WorldWideScience

Sample records for system reactive compensation

  1. Reactive power compensating system

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

    1987-01-01

    The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

  2. Reactive Power Compensating System.

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1985-01-04

    The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

  3. Reactive Power Compensator.

    Science.gov (United States)

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

  4. Reactive power compensator

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  5. Reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  6. Static reactive power compensators for high-voltage power systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

  7. Reactive Power Compensation Method Considering Minimum Effective Reactive Power Reserve

    Science.gov (United States)

    Gong, Yiyu; Zhang, Kai; Pu, Zhang; Li, Xuenan; Zuo, Xianghong; Zhen, Jiao; Sudan, Teng

    2017-05-01

    According to the calculation model of minimum generator reactive power reserve of power system voltage stability under the premise of the guarantee, the reactive power management system with reactive power compensation combined generator, the formation of a multi-objective optimization problem, propose a reactive power reserve is considered the minimum generator reactive power compensation optimization method. This method through the improvement of the objective function and constraint conditions, when the system load growth, relying solely on reactive power generation system can not meet the requirement of safe operation, increase the reactive power reserve to solve the problem of minimum generator reactive power compensation in the case of load node.

  8. Compensation of Reactive Power of Isolated Wind-Diesel Hybrid Power Systems

    Science.gov (United States)

    Sharma, P.; Bhatti, T. S.; Ramakrishna, K. S. S.

    2012-03-01

    This paper presents the automatic reactive power control of an isolated wind-diesel hybrid power system with a synchronous generator (SG) for a diesel genset and an induction generator (IG) with wind energy conversion systems (WECS) to generate electricity. To reduce the gap between reactive power generation and demand, a variable source of reactive power is used such as static synchronous compensator (STATCOM). The mathematical model of the system based on reactive power flow equations is developed. Three examples of the wind-diesel hybrid power systems are considered with different wind power generation capacities to study the effect of the wind power generation on the system performance. The study is based on small signal analysis by considering IEEE type-1 excitation system for the SG. The paper also shows the transient performance of the hybrid systems for 1 % step increase in reactive power load and 1 % step increase in reactive power load plus 1 % step increase in input wind power.

  9. Reactive Power Compensation Using an Energy Management System

    Science.gov (United States)

    2014-09-01

    power factor PG&E Pacific Gas and Electric PI proportional-integral PLL phase-locked loop PWM pulse width modulation RMS root mean square USMC...inverter via a bidirectional buck- boost converter . Pulse width modulation (PWM) with unipolar voltage switching delivers the H-bridge gate signals that...s. However, the inverter continues to sell reactive power to the grid, causing a spike in grid voltage. The inverter’s static synchronous

  10. Reactive power compensation a practical guide

    CERN Document Server

    Hofmann, Wolfgang; Just, Wolfgang

    2012-01-01

    The comprehensive resource on reactive power compensation, presenting the design, application and operation of reactive power equipment and installations The area of reactive power compensation is gaining increasing importance worldwide. If suitably designed, it is capable of improving voltage quality significantly, meaning that losses in equipment and power systems are reduced, the permissible loading of equipment can be increased, and the over-all stability of system operation improved. Ultimately, energy use and CO2 emisson are reduced. This unique guide discusses the

  11. Compensation for Harmonic Currents and Reactive Power in Wind Power Generation System using PWM Inverter

    Science.gov (United States)

    Shinohara, Katsuji; Shinhatsubo, Kurato; Iimori, Kenichi; Yamamoto, Kichiro; Saruban, Takamichi; Yamaemori, Takahiro

    In recent year, consciousness of environmental problems is enhancing, and the price of the electric power purchased by an electric power company is established expensive for the power plant utilizing the natural energy. So, the introduction of the wind power generation is promoted in Japan. Generally, squirrel-cage induction machines are widely used as a generator in wind power generation system because of its small size, lightweight and low-cost. However, the induction machines do not have a source of excitation. Thus, it causes the inrush currents and the instantaneous voltage drop when the generator is directly connected to a power grid. To reduce the inrush currents, an AC power regulator is used. Wind power generations are frequently connected to and disconnected from the power grid. However, when the inrush currents are reduced, harmonic currents are caused by phase control of the AC power regulator. And the phase control of AC power regulator cannot control the power factor. Therefore, we propose the use of the AC power regulator to compensate for the harmonic currents and reactive power in the wind power generation system, and demonstrate the validity of its system by simulated and experimental results.

  12. Study of static reactive power compensators for high-voltage power systems. Final report, May 12, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Byerly, R.T.; Bennon, R.J.; Taylor, E.R. Jr.; Poznaniak, D.T.

    1981-05-12

    A general study of the application of static VAR compensators (SVC's) to high-voltage transmission systems has been performed. Considerable emphasis has been placed on improvements to synchronous stability, and it is shown that SVC's can provide significant benefits in terms of damping for unstable modes of oscillation and increases in transient stability limits. This report includes descriptions of static VAR compensators, technical and economic comparisons of different compensators, compensator models for system studies, comprehensive study procedures, study results for two small-scale systems, and guidelines for SVC application.

  13. Engineering model of the electric drives of separation device for simulation of automatic control systems of reactive power compensation by means of serially connected capacitors

    Science.gov (United States)

    Juromskiy, V. M.

    2016-09-01

    It is developed a mathematical model for an electric drive of high-speed separation device in terms of the modeling dynamic systems Simulink, MATLAB. The model is focused on the study of the automatic control systems of the power factor (Cosφ) of an actuator by compensating the reactive component of the total power by switching a capacitor bank in series with the actuator. The model is based on the methodology of the structural modeling of dynamic processes.

  14. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...

  15. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  16. Coordination of baseload power plant group control with static reactive power compensator control

    Directory of Open Access Journals (Sweden)

    Zbigniew Szczerba

    2012-06-01

    Full Text Available Reactive power sources in power system nodes: generators and static reactive power compensators, are controlled by control systems. Generators – by generator node group controllers, compensators – by voltage controllers. The paper presents issues of these control systems’ coordination and proposals for its implementation.

  17. Advanced configuration of hybrid passive filter for reactive power and harmonic compensation.

    Science.gov (United States)

    Kececioglu, O Fatih; Acikgoz, Hakan; Sekkeli, Mustafa

    2016-01-01

    Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. Simulation results show that performance of reactive power and harmonic compensation with advanced hybrid passive filter is better than conventional hybrid passive filters.

  18. An introduction to reactive power compensation for wind farms

    International Nuclear Information System (INIS)

    Nigim, K.A.; Cairo Univ., Giza; Zobaa, A.F.; El Amin, I.

    2005-01-01

    The paper summarises the refereed contributions of seven articles reviewed for publication in the IJETP - Special Issue on 'Reactive compensation for wind farms'. The main goal of the special issue is to provide a forum to exchange information on the reactive power compensation requirements for wind farms and introducing possible price mechanisms for today's deregulated power industry. Uncompensated reactive power causes stress on the hosting utility grid as well as added expenses, which create in difficulties for power purchasing agreements from independent wind energy producers. Wind power producers need to comply with the hosting utility grid interconnection standards, e.g., voltage and frequency, as well as to provide controllable active and reactive sources of power. Active power supply is mainly dependent on the potential of wind power produced and the turbine design. Reactive power demand on the other hand depends on the conversion devices and the recovered power quantity fed to the grid. Static Var Compensators (SVC), Unified Power Quality Conditioners (UPQC), Unified Power Flow Controllers (UPFC), and the Distributed Static Synchronous Compensators (DSTATCOM) are all new emerging devices aimed at regulating the reactive power requirements. The excellent controllability of these devices has paved the way to flexible and dynamic controllers that are capable of regulating the flow of active and reactive power components. These devices are now suggested for the control of the reactive power requirement of wind generators. Studies have demonstrated acceptable voltage stabilisation results. This has increased the penetration level of wind power into existing distribution networks in many countries. (Author)

  19. Fail-safe reactivity compensation method for a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nygaard, Erik T.; Angelo, Peter L.; Aase, Scott B.

    2018-01-23

    The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.

  20. Advanced configuration of hybrid passive filter for reactive power and harmonic compensation

    OpenAIRE

    Kececioglu, O. Fatih; Acikgoz, Hakan; Sekkeli, Mustafa

    2016-01-01

    Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. ...

  1. Voltage Sag Mitigation and Load Reactive Power Compensation by UPQC

    OpenAIRE

    Ajitha, P; Jananisri, D

    2014-01-01

    This paper presents Unified Power Quality Conditioner(UPQC) that consist of series inverter and shunt inverter in back to back configuration which simultaneously compensate the power quality(PQ) problems of both voltage sag and load reactive power compensation . In this paper ,Neural network is tool which is considered for solving power quality problems. The simulation results from MATLAB/SIMULINK are discussed to validate the proposed method.

  2. An introduction to reactive power compensation for wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Nigim, K.A. [Waterloo Univ., Ont. (Canada). Dept. of Electrical and Computer Engineering; Cairo Univ., Giza (Egypt). Faculty of Engineering; Zobaa, A.F.; El Amin, I. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering

    2005-07-01

    The paper summarises the refereed contributions of seven articles reviewed for publication in the IJETP - Special Issue on 'Reactive compensation for wind farms'. The main goal of the special issue is to provide a forum to exchange information on the reactive power compensation requirements for wind farms and introducing possible price mechanisms for today's deregulated power industry. Uncompensated reactive power causes stress on the hosting utility grid as well as added expenses, which create in difficulties for power purchasing agreements from independent wind energy producers. Wind power producers need to comply with the hosting utility grid interconnection standards, e.g., voltage and frequency, as well as to provide controllable active and reactive sources of power. Active power supply is mainly dependent on the potential of wind power produced and the turbine design. Reactive power demand on the other hand depends on the conversion devices and the recovered power quantity fed to the grid. Static Var Compensators (SVC), Unified Power Quality Conditioners (UPQC), Unified Power Flow Controllers (UPFC), and the Distributed Static Synchronous Compensators (DSTATCOM) are all new emerging devices aimed at regulating the reactive power requirements. The excellent controllability of these devices has paved the way to flexible and dynamic controllers that are capable of regulating the flow of active and reactive power components. These devices are now suggested for the control of the reactive power requirement of wind generators. Studies have demonstrated acceptable voltage stabilisation results. This has increased the penetration level of wind power into existing distribution networks in many countries. (Author)

  3. Adaptive Compensation of Reactive Power With Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Hansen, Steffan

    2008-01-01

    This paper describes an adaptive method for compensating the reactive power with an active power filter (APF), which is initially rated for mitigation of only the harmonic currents given by a nonlinear industrial load. It is proven that, if the harmonic currents do not load the APF at the rated...

  4. Compensación de potencia reactiva en sistemas desbalanceados utilizando algoritmos genéticos Reactive power compensation in unbalanced systems using genetic algorithms

    Directory of Open Access Journals (Sweden)

    Davel Borges Vasconcellos

    2012-12-01

    Full Text Available La eficiencia energética de un sistema eléctrico depende en gran medida del factor de potencia con que opera y de una eficaz compensación de potencia reactiva si esta es necesaria. Una de las vías más utilizadas para efectuar la compensación del reactivo es el empleo de bancos de capacitores. La óptima aplicación de estos presupone tres aspectos: la selección de la capacidad más adecuada de los bancos, el tipo de compensador a utilizar, fijo o variable, así como la ubicación en el sistema de suministro eléctrico. En determinadas publicaciones, estos aspectos se tratan de forma independiente. Sin embargo, desde el punto de vista técnico ellos están mutuamente vinculados y todos poseen una implicación económica, lo que obliga a la necesidad de considerarlos en conjunto para un problema de optimización dado. Existen referencias de otros trabajos que desarrollan métodos que consideran estos aspectos de manera conjunta, pero presentan limitantes para ser aplicados en los sistemas de suministro eléctrico del sector terciario y donde predominan condiciones de desbalance. En este trabajo se presenta un método con el empleo de los algoritmos genéticos que posibilita una formulación más exacta del problema arrojando soluciones de mayor calidad. El programa desarrollado se soporta sobre software MATLAB, versión 7.8 (R2009a, utilizando las estructuras de programación de Genetic Algorithm and Direct Search Toolbox. La efectividad de su aplicación se muestra en casos de estudio correspondientes a sistemas de suministro eléctrico de dos hoteles pertenecientes al sector terciario en la provincia de Camagüey, Cuba.The energy efficiency of an electric system depends in great extent of the reactive power compensation that is carried out. One of the ways most used for reactive is power of capacitor banks. A good selection of these, presupposes three aspects: the selection of the banks capacity, the compensator type to be used and the

  5. Static compensators (STATCOMs) in power systems

    CERN Document Server

    Shahnia, Farhad; Ghosh, Arindam

    2014-01-01

    A static compensator (STATCOM), also known as static synchronous compensator, is a member of the flexible alternating current transmission system (FACTS) devices. It is a power-electronics based regulating device which is composed of a voltage source converter (VSC) and is shunt-connected to alternating current electricity transmission and distribution networks. The voltage source is created from a DC capacitor and the STATCOM can exchange reactive power with the network. It can also supply some active power to the network, if a DC source of power is connected across the capacitor. A STATCOM

  6. The Block Diagram for the Synchronous Motors used for the Compensation of the Reactive Power

    Directory of Open Access Journals (Sweden)

    Iulius Petrica

    2013-05-01

    Full Text Available The optimal control system for the compensation of the reactive power in an energetic consumer assembly is presented, containing one or more synchronous motors, connected to the same power bars in parallel, including asynchronous motors and static converters. The compensation of the reactive power absorbed from the system by the consumers is possible, using a optimal control system that controls the reactive power provided on the bars by the synchronous motors on condition that the power losses in the created whole are zero. A limited functional block diagram of the synchronous motor, which is the controlled object completed with the control circuits of the exciting tension and current is obtained having as set value the sum of all reactive currents of the consumers from the power assembly. The optimization is obtained using the module criterion of Kessler.

  7. Hybrid compensation arrangement in dispersed generation systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2005-01-01

    This paper presents a hybrid compensation system consisting of an active filter and distributed passive filters. In the system, each individual passive filter is connected to a distortion source and designed to eliminate main harmonics and supply reactive power for the distortion source, while...... the active filter is responsible for the correction of the system unbalance and the cancellation of the remaining harmonics. The paper also analyzes the effects of the circuit configuration on the system impedance characteristics and consequently the effectiveness of the filter system. Simulation studies...... are performed for a power system including the dispersed generation units connected into the system through power electronic converters and diode rectifier loads, which produce the distorted waveforms. The simulation results have demonstrated that good compensation effects can be achieved by using the combined...

  8. Hybrid compensation arrangement in dispersed generation systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2005-01-01

    This paper presents a hybrid compensation system consisting of an active filter and distributed passive filters. In the system, each individual passive filter is connected to a distortion source and designed to eliminate main harmonics and supply reactive power for the distortion source, while...... filter system consisting of distributed passive filters and an active filter....... the active filter is responsible for the correction of the system unbalance and the cancellation of the remaining harmonics. The paper also analyzes the effects of the circuit configuration on the system impedance characteristics and consequently the effectiveness of the filter system. Simulation studies...

  9. New developments in planning of reactive power compensation devices

    International Nuclear Information System (INIS)

    Blanchon, G.; Girard, N.; Logeay, Y.; Meslier, F.

    1987-01-01

    The need to compensate reactive-power is highlighted by the well-known problem that arises when starting up very powerful nuclear plants, sometimes located very far away from the areas of consumption. Since the EHV network is very expanded and highly meshed, such need varies considerably as a function of the availability of the generating units and the grid. To tackle this problem, the authors have drawn up a new, basically probabilistic, method which accounts for the great many different situations characterizing a large meshed network (1000 nodes) while providing reasonably safe operating conditions in case of n-1 contingency. It is today an operational method. The authors illustrate it with the results of a recent study on compensation device-planning on the EHV EDF network by 1990

  10. Principles for construction the compensators of reactive power with voltage stabilization for transformer substations

    Science.gov (United States)

    Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

    2017-10-01

    Based on the booster transformer and the transistor converter with a DC link, a system is proposed for fast and accurate unloading the electric network from reactive power with simultaneous stabilization of voltage among consumers. The system contains a discrete stage of reactive power compensation and adjustable part. The adjustable part includes series and parallel reactive power compensators. The series compensator consists of a booster transformer, a voltage inverter and is designed to be switched on to the high voltage of the transformer substations. The parallel compensator consists of a rectifier with an input choke and is connected to the low voltage of the substation. The rectifier and inverter are connected by a DC link with an LC filter. The rectifier regulates the output voltage and the phase of the sinusoidal input current. The inverter regulates the magnitude and phase of the voltage on the control winding of the booster transformer. The rectifier and inverter control systems are synchronized with the network and with pulse width modulation.

  11. Harmonic Resonance Damping with a Hybrid Compensation System in Power Systems with Dispersed Generation

    DEFF Research Database (Denmark)

    Chen, Zhe; Pedersen, John Kim; Blaabjerg, Frede

    2004-01-01

    A hybrid compensation system consisting of an active filter and a group of distributed passive filters has been studied previously. The passive filters are used for each distorting load or Dispersed Generation (DG) unit to remove major harmonics and provide reactive power compensation. The active...... filter is connected in parallel with the distributed passive filters and loads/DGs to correct the system unbalance and remove the remaining harmonic components. The effectiveness of the presented compensation system has also been demonstrated. This paper studies the performance of the hybrid compensation...... demonstrated that the harmonic resonance can be damped effectively. The hybrid filter system is an effective compensation system for dispersed generation systems. In the compensation system, the passive filters are mainly responsible for main harmonic and reactive power compensation of each individual load/ DG...

  12. EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6

  13. Dynamic Self Adjusting FACTS-Switched Filter Compensation Schemes for Wind-Smart Grid Interface Systems

    OpenAIRE

    Elgammal, Adel; Sharaf, Adel M.

    2016-01-01

    This paper validates a number of Flexible AC transmission system (FACTS) filter compensator devices on voltage stabilization and reactive power compensation in a distribution network with embedded wind energy conversion system (WECS).  The FACTS filter compensator schemes provide Better voltage stabilization, improved power quality, Interface security, efficient utilization, minimum harmonics levels and energy loss minimization of electricity networks with reactive power and FACTS control, wh...

  14. Single-Phase Boost Inverter-Based Electric Vehicle Charger With Integrated Vehicle to Grid Reactive Power Compensation

    DEFF Research Database (Denmark)

    Wickramasinghe Abeywardana, Damith Buddika; Acuna, Pablo; Hredzak, Branislav

    2018-01-01

    Vehicle to grid (V2G) reactive power compensation using electric vehicle (EV) onboard chargers helps to ensure grid power quality by achieving unity power factor operation. However, the use of EVs for V2G reactive power compensation increases the second-order harmonic ripple current component......-side capacitor without adversely affecting the EV battery. The operation of the boost inverter-based EV charger with second-order harmonic and switching frequency ripple current reduction, the dynamic behavior of the system, the transition between different operating modes, the DC-side capacitor voltage control...

  15. Settlement of reactive power compensation in the light of white certificates

    Science.gov (United States)

    Zajkowski, Konrad

    2017-10-01

    The article discusses the problem of the determination of savings on active energy as a result of a reactive power compensation. Statutory guidance on the required energy audit to obtain white certificates in the European Union was followed. The analysis was made on the basis of the Polish Law. The paper presents a detailed analytical method and an estimation method taking into account the impact on the line, the transformer and the generator. According to the relevant guidelines in the European Union, the reduction of CO2 emissions by calculating the saving of active power should be determined. The detailed method and an estimation method proposed for the determination of savings on active energy as a result of the reactive power compensation carried out possess some errors and inconvenience. The detailed method requires knowledge of the network topology and a determination of reactive power Q at each point of the network. The estimation method of analysis is easy in execution, especially if the consumer of energy is the main or the most significant purchaser of electricity in the network. Unfortunately, this latter method can be used only for activities that do not require high computational accuracy. The results obtained by this method are approximate values that can be used for the calculation of economic indicators. The estimation method is suitable for determining the number of white certificates when a power audit concerns a recipient of electricity, the structure of which is a large number of divisions scattered at many different locations in the power system.

  16. Settlement of reactive power compensation in the light of white certificates

    Directory of Open Access Journals (Sweden)

    Zajkowski Konrad

    2017-01-01

    The detailed method and an estimation method proposed for the determination of savings on active energy as a result of the reactive power compensation carried out possess some errors and inconvenience. The detailed method requires knowledge of the network topology and a determination of reactive power Q at each point of the network. The estimation method of analysis is easy in execution, especially if the consumer of energy is the main or the most significant purchaser of electricity in the network. Unfortunately, this latter method can be used only for activities that do not require high computational accuracy. The results obtained by this method are approximate values that can be used for the calculation of economic indicators. The estimation method is suitable for determining the number of white certificates when a power audit concerns a recipient of electricity, the structure of which is a large number of divisions scattered at many different locations in the power system.

  17. The Ormin software for the optimization of reactive energy compensation; Logiciel Ormin ou comment optimiser la compensation d`energie reactive

    Energy Technology Data Exchange (ETDEWEB)

    Kratz, M.

    1994-12-31

    The Ormin software allows for the determination of capacitor batteries to be installed in order to optimize the reactive energy compensation in an industrial plant, at the lowest cost; it gives also a compatibility diagnosis between capacitor batteries and harmonic current generating equipment. Cost estimation and calculation of investment payback periods are included

  18. Modern control of static var compensator for power system stability enhancement

    Directory of Open Access Journals (Sweden)

    Stelian-Emilian Oltean

    2012-06-01

    Full Text Available The effects of shunt compensation on power system transmission stability and modern approach of the reactive power control scheme have been investigated in this paper. Reactive power compensation is realized in shunt connection with two components: thyristor controlled reactor (TCR and thyristor switched capacitor (TSC. A special attention has been given in the following paragraphs to a modern control approach for power system stability enhancement which uses fuzzy logic. In the final part of the paper the modern control block scheme of static VAR compensator for reactive power in transmission systems is presented.

  19. Inductive voltage compensation in superconducting magnet systems

    International Nuclear Information System (INIS)

    Yeh, H.T.; Goddard, J.S.; Shen, S.S.

    1979-01-01

    This paper details several techniques of inductive voltage compensation developed for quench detection in superconducting magnet systems with multiple coils and power supplies, with particular application for the Large Coil Test Facility (LCTF). Sources of noise, their magnitudes, and the sensitivity required for normal zone detection to avoid damage to the magnets are discussed. Two passive compensation schemes (second difference and central difference) are introduced and illustrated by parameters of LCTF; these take advantage of coil symmetries and other system characteristics. An active compensation scheme based on current rate input fom pickup coils and utilizing theory on ac loss voltage for calibration was tested, and the experimental setup and test results are discussed

  20. What makes ecological systems reactive?

    Science.gov (United States)

    Snyder, Robin E

    2010-06-01

    Although perturbations from a stable equilibrium must ultimately vanish, they can grow initially, and the maximum initial growth rate is called reactivity. Reactivity thus identifies systems that may undergo transient population surges or drops in response to perturbations; however, we lack biological and mathematical intuition about what makes a system reactive. This paper presents upper and lower bounds on reactivity for an arbitrary linearized model, explores their strictness, and discusses their biological implications. I find that less stable systems (i.e. systems with long transients) have a smaller possible range of reactivities for which no perturbations grow. Systems with more species have a higher capacity to be reactive, assuming species interactions do not weaken too rapidly as the number of species increases. Finally, I find that in discrete time, reactivity is determined largely by mean interaction strength and neither discrete nor continuous time reactivity are sensitive to food web topology. 2010 Elsevier Inc. All rights reserved.

  1. Modelación de los efectos de la compensación de potencia reactiva en sistemas de suministro eléctrico Modelation of effects on reactive power compensation in secondary power systems

    Directory of Open Access Journals (Sweden)

    Davel Borges Vasconcellos

    2012-08-01

    Full Text Available Se presentan los inconvenientes de la potencia reactiva y a partir de allí se realiza la modelación matemática de los efectos económicos de ésta, aplicable a sistemas de suministro eléctrico. Los efectos tomados en cuenta son: los costos de inversión de los bancos de capacitores, los gastos de amortización de los bancos, los gastos de pérdidas de energía activa de los bancos, los beneficios por la mejora del factor de potencia, incluida la reducción de pérdidas de energía activa en el sistema, así como los beneficios por la liberación de la capacidad de carga, para el caso de empresas donde este aspecto pueda representar un atractivo económico. Para el análisis de los estados de carga antes y después de la compensación se utilizan algoritmos de flujos de potencia trifásicos, con el empleo de modelos de gráficos de carga ajustados, como aspecto novedoso. Estos efectos, de acuerdo con el sistema de tarifas eléctricas de Cuba, son integrados en una función de análisis económico, en este caso el Valor Actual Neto (VAN, la cual sirve de base para el planteamiento del problema de optimización, que puede derivar en la correcta selección de los dispositivos compensadores.The inconveniences of the reactive power are presented and from this are carried out the mathematical models of its economic effects applicable to secondary power systems. The effects taken into account are: the costs of the capacitors banks, the expenses of paying-off to the banks, the expenses of power losses to the banks, the benefits for the improvement of the power factor, included the reduction of power loss in the system, as well as the benefits for the liberation of the load capacity, to the case of companies where the latest aspect can represent an economic attractiveness. For the analysis after and before compensation, are consider load flow algorithm witch load model adjust. According to electrical tariff structures in Cuba, these effects are

  2. Towards a practical partial core transformer : compensation of reactive power requirements with a VSC

    Energy Technology Data Exchange (ETDEWEB)

    Bendre, V.; Bodger, P.; Wood, A. [Canterbury Univ., Christchurch (New Zealand). Dept. of Electrical and Computer Engineering

    2008-07-01

    In this study, a single-phase voltage source converter (VSC) STATCOM system was applied to a low voltage partial core transformer in order to compensate for the high lagging VARs of a partial core transformer. The transformer was then used as a full core transformer. The single phase partial core STATCOM transformer was modelled using a power system computer-aided design (PSCAD) electromagnetic transient direct current (EMTDC) program. The simulations were conducted to evaluate the partial core transformer's performance with inductive, capacitive and resistive loads. Short circuit and open circuit tests were conducted on the transformer's rectangular windings. The study showed that the STATCOM device can be used to reduce magnetizing reactance as well as to increase the reactive power requirement of partial core transformers. 14 refs., 2 tabs., 7 figs.

  3. Reactive power management in electric power systems - A case ...

    African Journals Online (AJOL)

    The reactive power consumption by industrial plants and generation patterns in the Ethiopian Electric Light and Power Authority's (EELPA) system is critically evaluated. The flaws in the incentive mechanism for reactive power compensation are identified and recommendations made. Further, the voltage profile at the ...

  4. Reactive power compensation considering high harmonics generation from internal and external nonlinear load

    Science.gov (United States)

    Skamyin, A. N.; Belsky, A. A.

    2017-10-01

    The paper deals with reactive power compensation by means of condenser batteries with harmonic distortions in voltage and current, resulting from internal and external nonlinear load regarding the connection point shared by consumers. The paper presents the dependencies of the capacitor’s overloading factor from the required reactive power for compensating. These relations can help to determine in which capacity area of the capacitor banks its operation is ensured without overload. The paper also presents algorithm for selecting parameters of condenser batteries which leads to minimization of the capacitors overload and maximization of the network power factor.

  5. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  6. Compensation systems for low temperature applications

    CERN Document Server

    Skoczen, Balzej T

    2004-01-01

    The book is dedicated to the behaviour of ductile materials at cryogenic temperatures, structural stability issues and reliability oriented parametric optimisation of compensation systems containing the corrugated bellows. The problems of local and global stability of systems containing bellows, coupling between the low-cycle fatigue and stability as well as evolution of plastic strain fields, micro-damage and strain induced phase transformation in the corrugated shells at cryogenic temperatures are presented. As a special feature reliability oriented optimum design of compensation systems under strength, stability, fatigue and geometrical constraints is discussed. The relevant applications in the particle accelerators and cryogenic transfer lines are shown.

  7. REACTIVE POWER COMPENSATION OF THE TRACTION NETWORK OF THE ELECTRIFIED RAILWAY TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Berzan V.P.

    2010-08-01

    Full Text Available The method of the parametrical analysis of reactive power compensation of traction network depending on load-ing position on stage between two traction substations is offered. Problem solutions are received in an explicit form at a unilateral and bilateral supplying of complex loading by traction network. The parametrical analysis of active loading influence on characteristics of the compensating devices mounted on low voltage bars of traction substations depending on a site of this loading between power supplies and the loading is made. It is shown, that depending on point of joining of active loading to network and its values the compensating device generally should generate both inductive, and capacitive reactive power for maintenance of power factor value of traction network .

  8. Transients in reactors for power systems compensation

    Science.gov (United States)

    Abdul Hamid, Haziah

    This thesis describes new models and investigations into switching transient phenomena related to the shunt reactors and the Mechanically Switched Capacitor with Damping Network (MSCDN) operations used for reactive power control in the transmission system. Shunt reactors and MSCDN are similar in that they have reactors. A shunt reactor is connected parallel to the compensated lines to absorb the leading current, whereas the MSCDN is a version of a capacitor bank designed as a C-type filter for use in the harmonic-rich environment. In this work, models have been developed and transient overvoltages due to shunt reactor deenergisation were estimated analytically using MathCad, a mathematical program. Computer simulations used the ATP/EMTP program to reproduce both single-phase and three-phase shunt reactor switching at 275 kV operational substations. The effect of the reactor switching on the circuit breaker grading capacitor was also examined by considering various switching conditions.. The main original achievement of this thesis is the clarification of failure mechanisms occurring in the air-core filter reactor due to MSCDN switching operations. The simulation of the MSCDN energisation was conducted using the ATP/EMTP program in the presence of surge arresters. The outcome of this simulation shows that extremely fast transients were established across the air-core filter reactor. This identified transient event has led to the development of a detailed air-core reactor model, which accounts for the inter-turn RLC parameters as well as the stray capacitances-to-ground. These parameters are incorporated into the transient simulation circuit, from which the current and voltage distribution across the winding were derived using electric field and equivalent circuit modelling. Analysis of the results has revealed that there are substantial dielectric stresses imposed on the winding insulation that can be attributed to a combination of three factors. (i) First, the

  9. Women's Experience in the Workers' Compensation System.

    Science.gov (United States)

    Guthrie, Robert; Jansz, Janis

    2006-09-01

    Gender differences is a question of major importance within workers' compensation given the increased role of women in the workforce over the past several decades. This article reviews literature relating to women's experiences following work injury. An Australian study is used as background to exploring the broad issue of the question of gender equity in workers' compensation. In doing so it takes account of historical, legal and medical issues. Women's experience in the workers' compensation system is different to that of men due to a range of factors. It is heavily influenced by the industrial environment in which they work. Women are paid less than men in many instances and work in gender-segregated circumstances, which often reduces their industrial bargaining power. Women also suffer different forms of injury and disease to men because of the different nature of their work. The Australian experience suggests that as a consequence of the combination of lesser industrial bargaining power, lower wages and differing forms of injury and disease women often receive less than men in compensation payments, struggle to obtain equity in the dispute resolution process and experience greater difficulties in returning to work following injury or disease.

  10. Phase Noise Compensation for OFDM Systems

    Science.gov (United States)

    Leshem, Amir; Yemini, Michal

    2017-11-01

    We describe a low complexity method for time domain compensation of phase noise in OFDM systems. We extend existing methods in several respects. First we suggest using the Karhunen-Lo\\'{e}ve representation of the phase noise process to estimate the phase noise. We then derive an improved datadirected choice of basis elements for LS phase noise estimation and present its total least square counterpart problem. The proposed method helps overcome one of the major weaknesses of OFDM systems. We also generalize the time domain phase noise compensation to the multiuser MIMO context. Finally we present simulation results using both simulated and measured phased noise. We quantify the tracking performance in the presence of residual carrier offset.

  11. Transient Stability Enhancement in Power System Using Static VAR Compensator (SVC

    Directory of Open Access Journals (Sweden)

    Youssef MOULOUDI

    2012-12-01

    Full Text Available In this paper, an indirect adaptive fuzzy excitation and static VAR (unit of reactive power, volt-ampere reactive compensator (SVC controller is proposed to enhance transient stability for the power system, which based on input-output linearization technique. A three-bus system, which contains a generator and static VAR compensator (SVC, is considered in this paper, the SVC is located at the midpoint of the transmission lines. Simulation results show that the proposed controller compared with a controller based on tradition linearization technique can enhance the transient stability of the power system under a large sudden fault, which may occur nearly at the generator bus terminal.

  12. A NEW RELAY DESIGN FOR REACTIVE POWER COMPENSATION AND ECONOMICAL COMPARISION WITH CLASSICAL RELAY

    Directory of Open Access Journals (Sweden)

    Mustafa ŞEKKELİ

    2007-02-01

    Full Text Available In most cases, reactive power compensation is otomatically achieved with reactive power control relay by switching on and off, stationary shunt capasitors to the electrical network. İn this study , a new relay has been designed and developed. İn this method, capasitors which is switched on and of are optimally choosen. İn classical relay , only one capasitor can be added or extructed to the network. But,in designing new relay, 1,2 or 3 capasitor banks which are nearest value for desired inductive reactive power can be optimally choosen. As a result , switching number of capacitor and contactor is reduced minimum value and line is loaded less inductive current , it means that less active power losses. New designed relay has been compared with classical one economically . This relay has been manufactured and approved experimantally.

  13. Análisis de la compensación de potencia reactiva en sistemas contaminados con armónicos; Analysis of the Reactive Power Compensation in Contaminated Systems with Harmonics

    Directory of Open Access Journals (Sweden)

    Secundino Marrero Ramírez

    2011-02-01

    Full Text Available En este artículo se presentan los resultados obtenidos en la evaluación de una red industrial con presenciade contaminación armónica, donde las cargas no lineales corresponden fundamentalmente a rectificadoresy variadores de velocidad. Se establecieron los armónicos típicos generados por estas cargas y ellopermitió determinar los niveles de distorsión armónica de tensión y corriente para analizar su influencia enla selección del banco de condensadores durante la compensación de la potencia reactiva atendiendo alcomportamiento del sistema ante diferentes estados de carga.  The article is given the evaluation obtained of an industrial network with the presence of harmoniccontamination, where the non lineal loads correspond fundamentally to rectifiers and variators of speed.Where the typical harmonic generated by these loads settled down and it allowed it to determine the levelsof harmonic distortion of tension and current to analyze their influence in the selection of the bank ofcondensers during the compensation of the power it reactivates assisting to the behavior of the systembefore different load states.

  14. The Compensation and Benefits System: Private Companies vs. Budgetary System

    Directory of Open Access Journals (Sweden)

    Aldea Bogdan

    2015-12-01

    Full Text Available The economic evolution of the last decades has entailed major changes concerning the Human Resource Management practices, in both private and budgetary sector of Romania. In order to maintain efficiency and market competitivity, a company must adapt to these changes by altering its human resource strategy since managers are encountering increasingly complex challenges as to attracting, motivating and retaining employees. Such an objective might be accomplished by elaborating a competitive system of employee compensation. This article focuses on the stage reached by the Human Resource Management in the compensation and benefits system of the private and budgetary sector. For the latter, we are focusing on the romanian system of higher education. This study demonstrates that the compensation and benefits system which is implemented in romanian universities is limited and can offer few opportunities as compared to the one implemented by private companies. It is worth saying that the legal system has a negative impact in this matter.

  15. MOTIVATION AND COMPENSATION IN HEALTH SYSTEM

    Directory of Open Access Journals (Sweden)

    K. N. Borisov

    2014-01-01

    Full Text Available By the defi nition accepted by WHO, «health» it is not simple absence of an illness, but a condition of full physical, moral, mental and social wellbeing. By this defi nition forms of behavior and a way of life of the people, allowing prolonging the period of active, creative and happy life are meant. Health of each person – the main value for modern society. A crisis state of population as open social system, it is shown by its indignation in reply to stressful infl uences of negative socio-economic factors. It is accompanied by change of a condition of the public health which level refl ects depth of occurring changes. In the conditions of market managing also, the policy in the fi eld of compensation, material encouragement and social support of medical workers essentially changes. A certain level of compensation regardless of should be guaranteed to the medical worker, whether mechanisms of economic incentives of its work are used or not. At the same time, the desire of the worker to hold a position with higher salary and desire to work on it is productive and is qualitative – far not same. Increase of material compensation not always leads to increase of labor motivation and aspiration it is better to work. Socially psychological bases of labor motivation of medical workers are those new approaches that will allow solving problems of increase of labor motivation more eff ectively. In article the assessment of labor motivation is analyzed by medical workers, measures for increase of labor motivation and according to improvement of quality of medical care are off ered. The majority of the western experts ineffi ciency of management recognize as the main problem of health care ofRussia. The conclusion that medical institutes, academies and institutes of a post degree obrazoyovaniye, professional development faculties, and, probably, and institutes an upravleyoniya, should adapt foreign experience (motivational, conceptual, technological

  16. MOTIVATION AND COMPENSATION IN HEALTH SYSTEM

    Directory of Open Access Journals (Sweden)

    K. N. Borisov

    2015-01-01

    Full Text Available By the definition accepted by WHO, «health» it is not simple absence of an illness, but a condition of full physical, moral, mental and social wellbeing. By this definition forms of behavior and a way of life of the people, allowing prolonging the period of active, creative and happy life are meant. Health of each person – the main value for modern society. A crisis state of population as open social system, it is shown by its indignation in reply to stressful influences of negative socio-economic factors. It is accompanied by change of a condition of the public health which level refl ects depth of occurring changes. In the conditions of market managing also, the policy in the field of compensation, material encouragement and social support of medical workers essentially changes. A certain level of compensation regardless of should be guaranteed to the medical worker, whether mechanisms of economic incentives of its work are used or not. At the same time, the desire of the worker to hold a position with higher salary and desire to work on it is productive and is qualitative – far not same. Increase of material compensation not always leads to increase of labor motivation and aspiration it is better to work. Socially psychological bases of labor motivation of medical workers are those new approaches that will allow solving problems of increase of labor motivation more effectively. In article the assessment of labor motivation is analyzed by medical workers, measures for increase of labor motivation and according to improvement of quality of medical care are off ered. The majority of the western experts inefficiency of management recognize as the main problem of health care ofRussia. The conclusion that medical institutes, academies and institutes of a post degree obrazoyovaniye, professional development faculties, and, probably, and institutes an upravleyoniya, should adapt foreign experience (motivational, conceptual, technological and

  17. Study on A Control Method of PAPF for Resonance Damping and Harmonics Compensation in Power System

    DEFF Research Database (Denmark)

    Zhou, Fang; Wu, Longhui; Chen, Zhe

    2009-01-01

    In power system, capacitors are widely used to compensate reactive power, which generally cause resonance problems in harmonic distorted network. In this paper, A method of using a parallel active power filter (PAPF) to damp the resonances is proposed. The proposed method is compound with traditi......In power system, capacitors are widely used to compensate reactive power, which generally cause resonance problems in harmonic distorted network. In this paper, A method of using a parallel active power filter (PAPF) to damp the resonances is proposed. The proposed method is compound...... with traditional method, it shows that whether the capacitor current is included in the detecting current of PAPF or not. Also the PAPF with proposed method has strong ability in harmonic compensation. Finally, the experiment results are presented to verify the analysis....

  18. Report of the working group for nuclear damage compensation system

    International Nuclear Information System (INIS)

    1989-01-01

    The Working Group for Nuclear Damage Compensation System was established within the Atomic Energy Commision of Japan on August 2, 1988. The Group has held five meetings to make a study on the revision of the reserve for nuclear damage compensation. The nuclear damage compensation system in Japan has been established under the Law Concerning Compensation for Nuclear Damages and the Law Concerning Contract for Compensation for Nuclear Damages. The former law requires the nuclear power plant operators to set up a reserve for damage compensation to ensure positive and quick payment of compensation in the event of an accident. The reserve is currently rely on liability insurance and a government compensation contract. The Working Group has concluded that the total reserve should be increased from the current yen10 bill. to yen30 bill. The amount of the reserve specified in the enforcement law for the Law Concerning Compensation for Nuclear Damages should also be increased accordingly. The Law Concerning compensation for Nuclear damage will also be applied to damage which occurs overseas as a result of an accident in Japan. (N.K.)

  19. Reactive Power Role and Its Controllability in AC Power Transmission Systems

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Blaabjerg, Frede

    2017-01-01

    affect the power system operation. Different reactive power generation technologies based on capacitors and power electronic converters are reviewed as possible sources for the reactive power compensation. Also, voltage and reactive power control methods of the mentioned technologies are briefly......This chapter is a general introduction to the reactive power role in the voltage control and the stability in power transmission systems. It starts with a brief overview of the potential limitations related to the transmission system loading and also different ways that the reactive power can...... explained for use in AC power transmission systems....

  20. Administrative compensation for medical injuries: lessons from three foreign systems.

    Science.gov (United States)

    Mello, Michelle M; Kachalia, Allen; Studdert, David M

    2011-07-01

    The United States requires patients injured by medical negligence to seek compensation through lawsuits, an approach that has drawbacks related to fairness, cost, and impact on medical care. Several countries, including New Zealand, Sweden, and Denmark, have replaced litigation with administrative compensation systems for patients who experience an avoidable medical injury. Sometimes called "no-fault" systems, such schemes enable patients to file claims for compensation without using an attorney. A governmental or private adjudicating organization uses neutral medical experts to evaluate claims of injury and does not require patients to prove that health care providers were negligent in order to receive compensation. Information from claims is used to analyze opportunities for patient safety improvement. The systems have successfully limited liability costs while improving injured patients' access to compensation. American policymakers may find many of the elements of these countries' systems to be transferable to demonstration projects in the U.S.

  1. Elements for the calculation of reactive energy compensation - II; Elementos para o calculo de compensacao de energia reativa - II

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Mathias [Lippstadt (Germany)

    2010-10-15

    The first part of this work, published on the prior edition of this periodical approached the fundaments requested for the calculation of the capacitor bank viewing to obtain a certain reactive power compensation. There exist however other objectives which use the described calculation principles, as it is described in this work sequence. (author)

  2. Autonomous Control of Current and Voltage Controlled DG Interface Inverters for Reactive Power Sharing and Harmonics Compensation in Islanded Microgrids

    DEFF Research Database (Denmark)

    Mousazadeh, Seyyed Yousef; Jalilain, Alireza; Savaghebi, Mehdi

    2018-01-01

    In microgrids, Voltage Source Inverters (VSIs) interfacing Distributed Generation (DG) units can be operated in Voltage or Current Controlled Modes (VCM/CCM). In this paper, a coordinated control of CCM and VCM units for reactive power sharing and voltage harmonics compensation is proposed....... This decentralized control scheme is based on the local measurement of signals. In this way, the need for communication links is removed which results in a simpler and more reliable structure compared to the communication based control structures. To be more exact, the VCM units contribute to harmonics compensation....... Experimental and simulation studies show that the harmonics compensation is achieved by using only local measurements in presence of virtual admittance/impedance schemes of CCM/VCM units. Furthermore, it is demonstrated that the reactive power sharing among the CCM and VCM units is obtained based...

  3. Wire compensation: Performance, SPS MDs, pulsed system

    CERN Document Server

    Dorda, U

    2008-01-01

    A wire compensation (BBLR) scheme has been proposed in order to improve the long range beam-beam performance of the nominal LHC and its phase 1 and phase 2 upgrades[1]. In this paper we present experimental experience of the CERN SPS wires (BBLR) and report on progress with the RF BBLR.

  4. Assessment of transient stability of cable based transmission grids with reactive power compensation

    DEFF Research Database (Denmark)

    Foo, Yii; Dall, Laurids; Silva, Filipe Miguel Faria da

    2017-01-01

    Underground transmission cables are gaining popularity due to its applications near cities and aesthetic purpose. For example in Denmark, the transmission power grid is changing significantly as many conventional overhead lines (OHL) are replaced by cables and more is expected over the coming years...... through a series of sensitivity analysis with respect to the cables compensation degree. A separate case of disconnecting the SRs of the faulted line is also carried out. The tendencies are initially observed and explained for smaller systems, Single-Machine Infinite Bus (SMIB) and 9-bus system...

  5. Dispersion Compensation of Fiber Optic Systems for KSC Applications

    Science.gov (United States)

    Kozaitis, Samuel P.; Hand, Larry

    1996-01-01

    Installed fibers such as those at the Kennedy Space Center (KSC) are optimized for use at 1310 nm because they have zero dispersion at that wavelength. An installed fiber system designed to operate at 1310 nm will operate at a much lower data rate when operated at 1550 nm because the dispersion is not zero at 1550 nm. Using dispersion measurements of both installed and dispersion compensating fibers, we compensated a 21.04 km length of installed fiber with 4.25 km of dispersion compensating fiber. Using the compensated fiber-optic link, we reduced the dispersion to 0.494 ps/nm-km, from an uncompensated dispersion of 16.8 ps/nm-km. The main disadvantage of the compensated link using DC fiber was an increase in attenuation. Although the increase was not necessarily severe, it could be significant when insertion losses, connector losses, and fiber attenuation are taken into account.

  6. Compensación de potencia reactiva mediante bancos asimétricos de capacitores; Reactive Power Compensation by Unbalanced Capacitor Banks

    Directory of Open Access Journals (Sweden)

    Ignacio Pérez Abril

    2011-02-01

    Full Text Available A pesar de que los sistemas de distribución primaria y secundaria son desbalanceados por naturaleza, lacompensación de potencia reactiva en estos sistemas, se realiza comúnmente mediante bancos decondensadores trifásicos balanceados. En este trabajo se presenta la formulación general para el problemade compensación de potencia reactiva en sistemas desbalanceados mediante bancos de condensadoresdesbalanceados. Se presentan cuatro ejemplos de compensación en el secundario de bancos desbalanceadosde transformadores monofásicos. Todos los ejemplos muestran que la compensación por bancosdesbalanceados de capacitores incrementa los beneficios con respecto al uso de bancos balanceados  In spite of the fact that primary and secondary distribution systems are unbalanced by nature, thereactive power compensation on these systems is commonly developed by the use of balanced capacitorbanks. In this paper, the general formulation for the reactive power compensation problem onunbalanced systems with unbalanced capacitor banks is developed. Four examples of reactive powercompensation on the secondary of unbalanced three-phase transformers banks are presented. All theexamples show that the compensation by unbalanced capacitor banks increases the active power lossessaving as well as reduce the transformer’s load and contributes to balance the line currents when the loadis unbalanced.

  7. REACT: A simple framework for reactive systems

    NARCIS (Netherlands)

    Holenderski, L.

    2008-01-01

    Many software/hardware systems developed in Philips Research, especially those that serve as demonstrators for research ideas or product proposals developed in the Lifestyle sector, are so-called reactive systems. A reactive system consists of sensors, actuators and a control module. Sensors and

  8. Performance and Analysis of Reactive Power Compensation by Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    Yogita Kumari

    2015-09-01

    Full Text Available The Unified Power Flow Controller (UPFC is the most versatile of the FACTS controllers envisaged so far. The main function of the UPFC is to control the flow of real and reactive power by injection of a voltage in series with the transmission line. Both the magnitude and the phase angle of the voltage can be varied independently. Real and Reactive power flow control can allow for power flow in prescribed routes, loading of transmission lines close to their thermal limits and can be utilized for improving transient and small signal stability of the power system. In this paper UPFC is incorporated in a SMIB (Single Machine Infinite Bus system and the response of SMIB system has been recorded with and without UPFC, thereafter the comparison of both the output has been done. When no UPFC is installed, real and reactive power through the transmission line cannot be controlled. This paper presents control and performance of UPFC intended for installation on that transmission line to control power flow. Installing the UPFC makes it possible to control amount of active power flowing through the line. Simulations are carried out using MATLAB software to validate the performance of the UPFC.

  9. TWO-LAYER PHASE COMPENSATING INTERFERENCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Georgiy V. Nikandrov

    2014-09-01

    Full Text Available The paper deals with creation of optical interferential coatings, giving the possibility to form the wave front without the change of energy characteristics of the incident and reflected radiation. Correction is achieved due to the layer, which thickness is a function of coordinate of an optical element surface. Selection technique is suggested for refractive index materials, forming two-layer interference coating that creates a coating with a constant coefficient of reflection on the surface of the optical element. By this procedure the change of coefficient of reflection for the optical element surface, arising because of the variable thickness is eliminated. Magnesium oxide and zirconium dioxide were used as the film-forming materials. The paper presents experimentally obtained thickness distribution of the layer, which is a part of the phase compensating coating. A new class of optical coatings proposed in the paper can find its application for correcting the form of a wave front.

  10. A respiratory compensating system: design and performance evaluation.

    Science.gov (United States)

    Chuang, Ho-Chiao; Huang, Ding-Yang; Tien, Der-Chi; Wu, Ren-Hong; Hsu, Chung-Hsien

    2014-05-08

    This study proposes a respiratory compensating system which is mounted on the top of the treatment couch for reverse motion, opposite from the direction of the targets (diaphragm and hemostatic clip), in order to offset organ displacement generated by respiratory motion. Traditionally, in the treatment of cancer patients, doctors must increase the field size for radiation therapy of tumors because organs move with respiratory motion, which causes radiation-induced inflammation on the normal tissues (organ at risk (OAR)) while killing cancer cells, and thereby reducing the patient's quality of life. This study uses a strain gauge as a respiratory signal capture device to obtain abdomen respiratory signals, a proposed respiratory simulation system (RSS) and respiratory compensating system to experiment how to offset the organ displacement caused by respiratory movement and compensation effect. This study verifies the effect of the respiratory compensating system in offsetting the target displacement using two methods. The first method uses linac (medical linear accelerator) to irradiate a 300 cGy dose on the EBT film (GAFCHROMIC EBT film). The second method uses a strain gauge to capture the patients' respiratory signals, while using fluoroscopy to observe in vivo targets, such as a diaphragm, to enable the respiratory compensating system to offset the displacements of targets in superior-inferior (SI) direction. Testing results show that the RSS position error is approximately 0.45 ~ 1.42 mm, while the respiratory compensating system position error is approximately 0.48 ~ 1.42 mm. From the EBT film profiles based on different input to the RSS, the results suggest that when the input respiratory signals of RSS are sine wave signals, the average dose (%) in the target area is improved by 1.4% ~ 24.4%, and improved in the 95% isodose area by 15.3% ~ 76.9% after compensation. If the respiratory signals input into the RSS respiratory signals are actual human respiratory

  11. System performance of new types of dispersion compensating fibres

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Tokle, Torger; Knudsen, Stig Nissen

    2001-01-01

    Summary form only given. The management of dispersion and non-linearities is of prime importance in WDM systems. Dispersion compensating fibres (DCF) are extremely attractive when used in conjunction with standard single mode fibres (SMF). New types of DCFs compensating for the dispersion of SMF...... in a 1:1 length ratio have been recently presented and intermediate types of DCF (compensating for SMF in a 1:2 or 1:3 length ratio) have also been designed and fabricated. The properties of the various types of available DCFs with dispersion of -17, -40, -54 and -100 ps/(nm.km), corresponding to SMF...... to DCF length ratios of about k=1 (inverse dispersion fibre - IDF), 2,3 and 6 (conventional DCF) respectively are shown. All these fibres also provide dispersion slope compensation. It can be seen that when the absolute value of the dispersion is reduced from DCF to IDF values, both attenuation and non...

  12. QKD system with fast active optical path length compensation

    Science.gov (United States)

    Park, Byung Kwon; Lee, Min Soo; Woo, Min Ki; Kim, Yong-Su; Han, Sang-Wook; Moon, Sung

    2017-06-01

    We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.

  13. Dimensional verification and location of the reactive static compensator in 220 kV; Verificacion del dimensionamiento y ubicacion del compensador estatico de reactivos en 220 kV

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Krekeler, Ubaldo [Administracion Nacional de Electricidad (ANDE), Asuncion (Paraguay)]. E-mail: ufernandez@ieee.org; Cardozo Sanchez, Freddy [Mirant Americas (United States)

    2001-07-01

    This work presents a determination verification of the compensation range and the location of reactive static compensator (RSC) in 220 kV. The verification is accomplished by analyses of the RSC effects in relation to the losses, loading and system voltage stability. The needed compensation range is investigated in full details, whereas that the required conversion level is directly related to this range. It is concluded that the RSC installation, foreseen for 2002, might be postponed for 2005/10 still without reinforcements in 500 kV. The Limpio substation seems to be the more suitable location in relation to the most analysed cases.

  14. Joint compensation of multiple RF impairments in MIMO STBC systems

    KAUST Repository

    Qi, Jian

    2011-09-01

    In this paper, we propose a compensation method for the joint effect of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk in multiple-input multiple-output (MIMO) orthogonal space-time block coding (OSTBC) systems. The performance of the MIMO OSTBC equipped with the proposed compensation mechanism is evaluated in terms of average symbol error probability and system capacity, in Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, and phase-shift keying modulation order. © 2011 IEEE.

  15. Investigation of SSR Characteristics of Hybrid Series Compensated Power System with SSSC

    Directory of Open Access Journals (Sweden)

    R. Thirumalaivasan

    2011-01-01

    Full Text Available The advent of series FACTS controllers, thyristor controlled series capacitor (TCSC and static synchronous Series Compensator (SSSC has made it possible not only for the fast control of power flow in a transmission line, but also for the mitigation of subsynchronous resonance (SSR in the presence of fixed series capacitors. SSSC is an emerging controller and this paper presents SSR characteristics of a series compensated system with SSSC. The study system is adapted from IEEE first benchmark model (FBM. The active series compensation is provided by a three-level twenty four-pulse SSSC. The modeling and control details of a three level voltage source converter-(VSC-based SSSC are discussed. The SSR characteristics of the combined system with constant reactive voltage control mode in SSSC has been investigated. It is shown that the constant reactive voltage control of SSSC has the effect of reducing the electrical resonance frequency, which detunes the SSR. The analysis of SSR with SSSC is carried out based on frequency domain method, eigenvalue analysis and transient simulation. While the eigenvalue and damping torque analysis are based on linearizing the D-Q model of SSSC, the transient simulation considers both D-Q and detailed three phase nonlinear system model using switching functions.

  16. An Integrated Thermal Compensation System for MEMS Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Sheng-Ren Chiu

    2014-03-01

    Full Text Available An active thermal compensation system for a low temperature-bias-drift (TBD MEMS-based gyroscope is proposed in this study. First, a micro-gyroscope is fabricated by a high-aspect-ratio silicon-on-glass (SOG process and vacuum packaged by glass frit bonding. Moreover, a drive/readout ASIC, implemented by the 0.25 µm 1P5M standard CMOS process, is designed and integrated with the gyroscope by directly wire bonding. Then, since the temperature effect is one of the critical issues in the high performance gyroscope applications, the temperature-dependent characteristics of the micro-gyroscope are discussed. Furthermore, to compensate the TBD of the micro-gyroscope, a thermal compensation system is proposed and integrated in the aforementioned ASIC to actively tune the parameters in the digital trimming mechanism, which is designed in the readout ASIC. Finally, some experimental results demonstrate that the TBD of the micro-gyroscope can be compensated effectively by the proposed compensation system.

  17. Persistent failure of the COIDA system to compensate occupational ...

    African Journals Online (AJOL)

    Cases of occupational disease, solvent encephalopathy and occupational asthma are used to exemplify failings of the workers' compensation system in South Africa, that include delays in processing claims, non-response to requests for information, and inadequate assessment of disability. These and other systemic ...

  18. Optimal design of passive gravity compensation system for articulated robots

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Gyun; Lee, Jae Young; Kim, Sang Hyun; Kim, Sung Rak [Hyundai Heavy Industries Co. Ltd., Daejeon (Korea, Republic of)

    2012-01-15

    In this paper, the optimal design of a spring type gravity compensation system for an articulated robot is presented. Sequential quadratic programming (SQP) is adopted to resolve various nonlinear constraints in spring design such as stress, buckling, and fatigue constraints, and to reduce computation time. In addition, continuous relaxation method is used to explain the integer valued design variables. The simulation results show that the gravity compensation system designed by proposed method improves the performance effectively without additional weight gain in the main workspace.

  19. Local dynamic range compensation for scanning electron microscope imaging system.

    Science.gov (United States)

    Sim, K S; Huang, Y H

    2015-01-01

    This is the extended project by introducing the modified dynamic range histogram modification (MDRHM) and is presented in this paper. This technique is used to enhance the scanning electron microscope (SEM) imaging system. By comparing with the conventional histogram modification compensators, this technique utilizes histogram profiling by extending the dynamic range of each tile of an image to the limit of 0-255 range while retains its histogram shape. The proposed technique yields better image compensation compared to conventional methods. © Wiley Periodicals, Inc.

  20. Simplified dead-time compensator for multiple delay SISO systems.

    Science.gov (United States)

    Torrico, Bismark Claure; Correia, Wilkley Bezerra; Nogueira, Fabrício Gonzalez

    2016-01-01

    This paper presents a dead-time compensation structure able to deal with stable and unstable multiple delay single input single output (SISO) systems. The proposed method aims to simplify the primary controller by replacing it for FIR filters placed at the feedback path. Such modification reduces the total number of parameters to be tuned which facilitates the overall design in comparison with other primary controllers normally considered. Simulation results show a better performance for the proposed control approach compared with other dead-time compensator (DTC) recently proposed in the literature. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Prototype for harmonic compensation in three phase systems

    Directory of Open Access Journals (Sweden)

    Alfonso Alzate Gómez

    2017-02-01

    Full Text Available Context: The traditional methodology for the control of harmonics consists in the use of passive filters tuned to the harmonic components to be eliminated. Passive filters require a frequency-demanding design to avoid resonance phenomena with other elements and they not respond to changes in the dynamics of the electric power system. Method: A best-performing solution alternative is parallel power active filters. These filters, unlike passive filters, inject compensation currents into the network and have adaptation  to changes in operating conditions. The implementation of an active filter involves hardware development but also software development. Algorithms are required for calculation of compensation currents and dc bus voltage control. Results: In this work a prototype for the harmonic compensation of 5kVA is designed and built in three phase distribution systems of 220V. The hardware fundamental elements are: coupling coil, capacitor, semiconductor devices and controller. The control algorithms that are responsible for the operation of the active filter at each instant of time are PQ theory, Linear Control-PWM and PI Control. Conclusions: The active power filters are a solution to the presence of harmonics in power systems. They compensate the harmonics generated by nonlinear loads and they don‘t have resonance problems and good dynamic response.

  2. Multiagent voltage and reactive power control system

    Directory of Open Access Journals (Sweden)

    I. Arkhipov

    2014-12-01

    Full Text Available This paper is devoted to the research of multiagent voltage and reactive power control system development. The prototype of the system has been developed by R&D Center at FGC UES (Russia. The control system architecture is based on the innovative multiagent system theory application that leads to the achievement of several significant advantages (in comparison to traditional control systems implementation such as control system efficiency enhancement, control system survivability and cyber security.

  3. Technology of VAr Compensators for Induction Generator Applications in Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    A. F. Zobaa

    2006-09-01

    Full Text Available Many of today utility interconnected wind farms use induction generator (IG to convert the captured wind mechanical power into electricity. Induction generator has some advantages over the synchronous generator (SG. The main advantages are its robustness and its capability to be synchronized directly to the grid. The main disadvantage, however, is its dependency on the grid for supplying its own reactive power ‘VAr’. Whether fixed or adjustable VAr systems are connected across its terminal, IG must operate at unity power factor at the rated loading while the wind power varies. With supervised control and appropriate coordination, VAr can be used to the benefits of both the wind farm developer and the hosting utility. The incorporation of today adjustable reactive power compensators such as the Static VAr Compensation (SVC and Static Synchronous Compensator (STATCOM with IG are vital ingredient toward a successful penetration of wind energy in today distribution grid to ensure voltage stability during the steady state and transient periods.

  4. Compensation of Reactive Power from Wind Turbines with Power Electronics Equipment

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Kaas

    1996-01-01

    that the supply line must deliver the reactive current with ensuing losses, the strong variation also will cause varying inductive voltage losses in the supply with flicker as a consequence. With power electronic equipment it is possible to produce the reactive power on location and reduce the losses and voltage...

  5. Synchronization of two chaotic systems: Dynamic compensator approach

    International Nuclear Information System (INIS)

    Chen, C.-K.; Lai, T.-W.; Yan, J.-J.; Liao, T.-L.

    2009-01-01

    This study is concerned with the identical synchronization problem for a class of chaotic systems. A dynamic compensator is proposed to achieve the synchronization between master and slave chaotic systems using only the accessible output variables. A sufficient condition is also proposed to ensure the global synchronization. Furthermore, the strictly positive real (SPR) restriction, which is normally required in most of the observer-based synchronization schemes, is released in our approach. Two numerical examples are included to illustrate the proposed scheme.

  6. Simulation of an active filter for compensation of reactive power and suppression of harmonic currents in the phases and in the neuter of an unbalanced three-phase system of 4 wires; Simulacion de un filtro activo para compensacion de potencia reactiva y supresion de corrientes armonicas en las fases y en el neutro de un sistema trifasico de 4 kilos desbalanceado

    Energy Technology Data Exchange (ETDEWEB)

    Mino Aguilar, Gerardo

    1999-05-01

    In here it is presented a brief review of the state of art of power active filters used in the common coupling points between AC sources and nonlinear loads formed by static converters of AC/DC, for the suppression of harmonic currents and instantaneous compensation of the reactive power. Starting off from the active filters that affect only the three balanced currents of the three-phase systems of 3 wires, it is arrived at the subject of this thesis, whose objective is to solve the problem of the reactive compensation and suppression of harmonic currents in the three phases as well as in the neuter of the three-phase systems of 4 wires. The main contribution of this thesis is the design, analysis and simulation of an active filter that besides of suppressing the harmonic currents and compensating the power factor in the three phases of an unbalanced three-phase system, also has the capacity of removing the current that circulates in the neuter due to the unbalance of the phase currents. This design is based on the extension of the theory of the instantaneous reactive power that includes the existence of the zero sequence components of in the phase currents. It is set out in the thesis a novel filter based on an three-phase inverter of 4 branches, 3 branches of phase and one branch of neuter, that to the best knowledge of the author it has not been reported in the literature. Use is made of an extensive number of simulation results to prove the validity of this filter, whose behavior is superior to the filters for suppression of currents in the neuter existing in the literature, of which also a comparative study is presented. The thesis also includes a mathematical and graphical analysis of the symmetrical components in balanced and unbalanced systems in order to know the nature of the harmonic currents of zero sequence. It is included a section on causes and effects of the harmonic contamination problem. [Spanish] Se presenta un breve revision del estado del

  7. Integration of Renewable Energy for the Harmonic Current and Reactive Power Compensation

    DEFF Research Database (Denmark)

    Pouresmaeil, Edris; Shaker, Hamid Reza; Mehrasa, Majid

    2015-01-01

    This paper deals with a control technique for multilevel converter topologies base on Direct Lyapunov Control Method (DLCM) for integration of Renewable Energy Resources (RER) into the power grid. The compensation of variations in reference current components is considered properly in this control...

  8. Research on reflective optical telescope system's wavefront aberration compensation method

    Science.gov (United States)

    Duan, Xueting

    Wavefront aberration measurement of the image quality of reflective telescope system which has a large aperture and long focal length is one of the frequently-used methods of high-precision test and alignment. It was widely used during the large aperture telescope manufacturing process. The influences of surface shape error of the reflective optical telescope system components were simulated and analyst by input the actual measuring data into the optical design software CODE V in this article. According to the test results compared to the alignment process, the accuracy of the simulation method was indicated. At the same time, the wavefront aberration optical compensation principle of the reflective optical telescope system was proved by the simulation of alignment. And in this article, the feasibility of the application of optical phase compensation alignment method was investigated.

  9. Ten years' experience using an integrated workers' compensation management system to control workers' compensation costs.

    Science.gov (United States)

    Bernacki, Edward J; Tsai, Shan P

    2003-05-01

    This work presents 10 years of experience using an Integrated Workers' Compensation Claims Management System that allows safety professionals, adjusters, and selected medical and nursing providers to collaborate in a process of preventing accidents and expeditiously assessing, treating, and returning individuals to productive work. The hallmarks of the program involve patient advocacy and customer service, steerage of injured employees to a small network of physicians, close follow-up, and the continuous dialogue between parties regarding claims management. The integrated claims management system was instituted in fiscal year 1992 servicing a population of approximately 21,000 individuals. The system was periodically refined and by the 2002 fiscal year, 39,000 individuals were managed under this paradigm. The frequency of lost-time and medical claims rate decreased 73% (from 22 per 1000 employees to 6) and 61% (from 155 per 1000 employees to 61), respectively, between fiscal year 1992 and fiscal year 2002. The number of temporary/total days paid per 100 insureds decreased from 163 in fiscal year 1992 to 37 in fiscal year 2002, or 77%. Total workers' compensation expenses including all medical, indemnity and administrative, decreased from $0.81 per $100 of payroll in fiscal year 1992 to $0.37 per $100 of payroll in fiscal year 2002, a 54% decrease. More specifically, medical costs per $100 of payroll decreased 44% (from $0.27 to $0.15), temporary/total, 61% (from $0.18 to $0.07), permanent/partial, 63% (from $0.19 to $0.07) and administrative costs, 48% ($0.16 to $0.09). These data suggests that workers' compensation costs can be reduced over a multi-year period by using a small network of clinically skilled health care providers who address an individual workers' psychological, as well as physical needs and where communication between all parties (e.g., medical care providers, supervisors, and injured employees) is constantly maintained. Furthermore, these results

  10. Continuous reactivity calculation for subcritical system

    International Nuclear Information System (INIS)

    Silva, Cristiano; Goncalves, Alessandro C.; Martinez, Aquilino S.; Silva, Fernando C. da

    2011-01-01

    With the rise of a new generation of nuclear reactors as for existence the ADS (Accelerator-Driven System), it is important to have a fast and accurate prediction of the variation in reactivity during a possible variation in the intensity of external sources. This paper presents a formulation for the calculation of reactivity in subcritical systems using the inverse method related only to nuclear power derivatives. One of the applications of the proposed method is the possibility of developing reactimeters that allow the continuous monitoring of subcritical systems. (author)

  11. Continuous reactivity calculation for subcritical system

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cristiano; Goncalves, Alessandro C.; Martinez, Aquilino S.; Silva, Fernando C. da, E-mail: cristiano@herzeleid.net, E-mail: aquilino@lmp.ufrj.br, E-mail: fernando@con.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Palma, Daniel A.P., E-mail: dapalma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    With the rise of a new generation of nuclear reactors as for existence the ADS (Accelerator-Driven System), it is important to have a fast and accurate prediction of the variation in reactivity during a possible variation in the intensity of external sources. This paper presents a formulation for the calculation of reactivity in subcritical systems using the inverse method related only to nuclear power derivatives. One of the applications of the proposed method is the possibility of developing reactimeters that allow the continuous monitoring of subcritical systems. (author)

  12. Friction characterization and compensation in electro-mechanical systems

    Science.gov (United States)

    Tjahjowidodo, Tegoeh; Al-Bender, Farid; Van Brussel, Hendrik; Symens, Wim

    2007-12-01

    Friction characterization is a prerequisite for an accurate control of electromechanical systems. This paper considers the identification and control of friction in a high load torque DC motor to the end of achieving accurate tracking. In the first place, model-based feedforward controllers for friction compensation are considered. For this purpose, friction model structures ranging from the classical Coulomb model through the recently developed generalized Maxwell slip (GMS) model are employed. The performance of those models is compared and contrasted in regard both to identification and to compensation. Subsequently, having an accurate model of the system, model-based feedback controllers are also considered, namely the DNPF and the gain scheduling controllers. We show further that the gain scheduling controller yields best performance.

  13. Hybrid harmonic compensation device adapted for variable speed drive system

    Science.gov (United States)

    Abramovich, B. N.; Sychev, Yu A.; Zimin, R. Yu

    2017-10-01

    The structure of the hybrid harmonic compensation device adapted for variable speed drive system is proposed in the paper. The main feature of the proposed device is the usage of common direct current link both for inverter of power frequency converter and for inverter of active part of the hybrid device. This decision allows to decrease the cost of active part of the proposed hybrid device. The proposed hybrid device is firstly intended for voltage and current harmonic determination and elimination. A mathematical model of generalized industrial power supply system with nonlinear load and the proposed hybrid device was developed by means of Matlab Simulink software. During simulation the proper efficiency of the proposed hybrid device is shown in different modes of voltage and current harmonic compensation.

  14. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  15. Design and synthesis of reactive separation systems

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, M.F.

    1992-01-01

    During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

  16. Study, analysis and simulation of a static compensator D-STATCOM for distribution systems of electric power

    Directory of Open Access Journals (Sweden)

    Ahmed MOKHTARI

    2014-11-01

    Full Text Available Flexible Alternative Current Transmission System « FACTS » devices are controllers based on power electronics. It has been demonstrated that they can improve transient stability and help to damp electromechanical oscillations in distribution power systems. The aim of this paper was to clarify the power flow without and with a Distribution Static Compensator « D-STATCOM » and to improve the quality of the Algerian network. It is a shunt compensation device which is generally used to solve power quality problems in distribution systems. The present work will use these devices to study the functions available in the control of reactive power compensation as well as maintaining voltage. The simulation is done under MATLAB/SIMULINK for D-STATCOM and voltage source converter (VSC. Through this paper, D-STATCOM has demonstrated excellent performance and effectively improved the power quality in distribution networks.

  17. Readout Circuits for Noise Compensation in ISFET Sensory System

    Science.gov (United States)

    Das, M. P.; Bhuyan, M.; Talukdar, C.

    2015-12-01

    This paper presents two different noise reduction techniques for ion sensitive field effect transistor (ISFET) readout configuration and their comparison. The proposed circuit configurations are immune to the noise generated from the ISFET sensory system and particularly to the low frequency pH dependent 1/ f electrochemical noise. The methods used under this study are compensation of noise by differential OPAMP based and Wheatstone bridge circuit, where two identical commercial ISFET sensors were used. The statistical and frequency analysis of the data generated by this two methods were compared for different pH value ranging from pH 2 to 10 at room temperature, and it is found that the readout circuits are able to compensate the noise to a great extent.

  18. Compensation of Imperfections for Vibratory Gyroscope Systems Using State Observers

    Directory of Open Access Journals (Sweden)

    Chien-Yu CHI

    2009-08-01

    Full Text Available This paper presents a novel approach that can compensate errors resulting from the imperfections of mechanical structures and interface circuits for MEMS gyroscope systems. Different from most of existing researches on gyroscopes wherein the mechanical structure and interface circuit are either assumed to be ideal or optimized individually, this approach uses state estimation techniques to compensate all those errors and to obtain correct angular rates in real time. The mechanical structure errors discussed in this paper may come from structure designs and fabrication imperfections. The interface circuit errors include: mismatch of differential capacitors, parasitic capacitance, offset voltage of operation amplifiers, and circuit noise. Simulation results indicates that, with the presence of those errors and a signal-to-noise ratio around 20, the proposed method can measure time-varying angular rates with a bandwidth up to 30 Hz and a sensing accuracy of 1×10-2 rad/sec.

  19. Time evolution of a small reactive system

    Directory of Open Access Journals (Sweden)

    J.P. Badiali

    2013-01-01

    Full Text Available We investigate the irreversible evolution of a small system in which a chemical reaction takes place. We have two main goals: the first requires to find an equation to produce a time-irreversible behavior,the second consists in introducing a simple exactly solvable model in order to understand basic facts in chemical kinetics. Our basic tool is the transition function counting the number of paths joining two points in the reactive coordinates system. An exact quantum Smoluchowski equation is derived for the reactive system in vacuum, in presence of a solvent in equilibrium at any time with the reactive system a new Smoluchowski equation is obtained. The transition from a quantum regime to a classical one is discussed. The case of a reactive system not in equilibrium with its neighborhood is investigated in terms of path integral and via a partial differential function. Memory effects and closure assumptions are discussed. Using a simple potential model the chemical rate constant is calculated exactly and questions such as the meaning of the activation energy or the physical content of the so-called prefactor are investigated.

  20. (statcom) in synchronous compensator

    African Journals Online (AJOL)

    eobe

    for adoption of advanced control technologies such as Flexible Alternating Current Transmission System (FACTS) with fast ... APPLICATION OF STATIC SYNCHRONOUS COMPENSATOR (STATCOM) IN IMPROVING POWER SYSTEM PERFORMANCE, R.A Jokojeje .... supply at bus i and is the reactive power demand at.

  1. Wind plant interaction with series-compensated power systems

    Science.gov (United States)

    Ramamurthy, Jayanth R.

    Wind power based generation has been rapidly growing world-wide during the recent past. In order to transmit large amounts of wind power over long distances, system planners may often add series compensation to existing transmission lines owing to several benefits such as improved steady-state power transfer limit, improved transient stability, and efficient utilization of transmission infrastructure. Application of series capacitors has posed resonant interaction concerns such as through subsynchronous resonance (SSR) with conventional turbine-generators. Wind turbine-generators may also be susceptible to such resonant interactions. However, not much information is available in literature and even engineering standards are yet to address these issues. The motivation problem for this research is based on an actual system switching event that resulted in undamped oscillations in a 345-kV series-compensated, typical ring-bus power system configuration. Based on time-domain ATP (Alternative Transients Program) modeling, simulations and analysis of system event records, the occurrence of subsynchronous interactions within the existing 345-kV series-compensated power system has been investigated. Effects of various small-signal and large-signal power system disturbances with both identical and non-identical wind turbine parameters (such as with a statistical-spread) has been evaluated. Effect of parameter variations on subsynchronous oscillations has been quantified using 3D-DFT plots and the oscillations have been identified as due to electrical self-excitation effects, rather than torsional interaction. Further, the generator no-load reactance and the rotor-side converter inner-loop controller gains have been identified as bearing maximum sensitivity to either damping or exacerbating the self-excited oscillations. A higher-order spectral analysis method based on modified Prony estimation has been successfully applied to the field records identifying dominant 9.79 Hz

  2. Reactivity Measurement and Analysis System (RMAS-7)

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, D.; Izquierdo, J.

    2015-07-01

    This paper tries to describe the Reactivity Measurement and Analysis System 7 (RMAS-7), which is an Areva’s hardware and software solution capable of accomplishing the physic startup tests in a work shift. RMAS-7 is a modular solution designed to be a powerful, convenient data collection and analysis system based on Ethernet communication network. This last feature allows RMAS-7 to have a distributed architecture. (Author)

  3. ACCOUNTING OF REACTIVE POWER COMPENSATION LEVEL AT PAYMENT CALCULATION OF TECHNOLOGICAL CONSUMPTION (LOSSES OF ELECTRIC POWER FOR ITS TRANSMISSION IN POWER NETWORK

    Directory of Open Access Journals (Sweden)

    E. P. Zabello

    2005-01-01

    Full Text Available The method is proposed to make a correction in payment for consumption of reactive energy and power which is attributed to deviation of actual activation energy losses for reactive power compensation from their standard value. It is recommended to calculate standard loss values for every voltage level and actual loss values are to be determined with the help of application of remote electronic accounting means in the current mode of power consumption.

  4. Reactive Power Sharing and Voltage Harmonic Distortion Compensation of Droop Controlled Single Phase Islanded Microgrids

    DEFF Research Database (Denmark)

    Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

    2014-01-01

    When paralleling multiple inverters that are capable of operating as an island, the inverters typically employ the droop control scheme. Traditional droop control enables the decentralized regulation of the local voltage and frequency of the microgrid by the inverters. The droop method also enabl...... and reduction of the voltage harmonic distortion at the point of common coupling (PCC). Experimental results were then presented to show the suitability of the proposed algorithms in achieving reactive power sharing and in improving the voltage harmonic distortion at the PCC....

  5. Motor System Plasticity and Compensation in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Daniel Zeller

    2013-07-01

    Full Text Available Multiple sclerosis (MS affects the central nervous system (CNS by inflammatory lesions, direct axonal injury, and by a rather diffuse and widespread neurodegeneration. For a long time, research has mainly focused on these destructive aspects of MS, while the compensatory effects of cellular repair and neural plasticity have received little consideration. However, as current effective immunomodulatory therapies may limit rather than preclude demyelination and axonal damage, additional therapeutic strategies promoting compensation of CNS damage might be of great use for preventing persistent impairment in MS. As a precondition for the development of such strategies, which may encompass pharmacological and behavioural interventions, but also non-invasive stimulation techniques, it seems fundamental to get deeper insights into the mechanisms of plasticity and adaptation at the systemic level. This review will provide a brief overview of what is known about plasticity of the motor system in patients with MS at present, with the main focus relying on evidence from functional imaging, neurophysiology, and motor learning. Overall, rapid-onset motor plasticity seems to be preserved even in advanced stages of the disease. Reorganisation processes, which can be shown early in the course of MS, are functionally relevant for motor compensation. In advanced MS, however, the brain´s adaptive reserve might be exhausted due to exceeding CNS injury. Future studies should address the question of how the later stages of central motor plasticity can be promoted best to preserve the patient´s autonomy for as long as possible.

  6. ADRC system of FSM for image motion compensation

    Science.gov (United States)

    Wang, Kaidi; Su, Xiuqin; Li, Zhe; Wu, Shaobo

    2017-02-01

    In order to increase the speed controlling accuracy of fast steering mirror (FSM) for image motion compensation and thus to increase the definition of picture taken by moving camera, active disturbance rejection control (ADRC) is designed. First, mathematical model of FSM driven by voice coil motor (VCM) is established. Next, ADRC algorithm and its simplified form in actual application are clarified. Finally, simulation research for controlled object is made. The result is compared to control effect of PID. Simulation curves demonstrate that the settling time of ADRC is 6 ms and the bandwidth of system attains 102.2 Hz, which are nearly the same as those of PID. When the error is very small, it can converge to zero at a faster rate if ADRC is used. When the same range disturbance is given to system, the relative error of ADRC reaches 0.050%, which is about 42% of that of PID.

  7. Research methods of simulate digital compensators and autonomous control systems

    Directory of Open Access Journals (Sweden)

    V. S. Kudryashov

    2016-01-01

    Full Text Available The peculiarity of the present stage of development of the production is the need to control and regulate a large number of process parameters, the mutual influence on each other that when using single-circuit systems significantly reduces the quality of the transition process, resulting in significant costs of raw materials and energy, reduce the quality of the products. Using a stand-alone digital control system eliminates the correlation of technological parameters, to give the system the desired dynamic and static properties, improve the quality of regulation. However, the complexity of the configuration and implementation of procedures (modeling compensators autonomous systems of this type, associated with the need to perform a significant amount of complex analytic transformation significantly limit the scope of their application. In this regard, the approach based on the decompo sition proposed methods of calculation and simulation (realization, consisting in submitting elements autonomous control part digital control system in a series parallel connection. The above theoretical study carried out in a general way for any dimension systems. The results of computational experiments, obtained during the simulation of the four autonomous control systems, comparative analysis and conclusions on the effectiveness of the use of each of the methods. The results obtained can be used in the development of multi-dimensional process control systems.

  8. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Søbrink, K.H.; Pedersen, Jørgen Kaas; Pedersen, Knud Ole Helgesen

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop and investig......Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop...... and investigate the use of a STATCOM by modelling and field testing an 8 MVar unit in a 24 MW wind farm....

  9. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop...

  10. Modelling and automatic reactive power control of isolated wind-diesel hybrid power systems using ANN

    International Nuclear Information System (INIS)

    Bansal, R.C.

    2008-01-01

    This paper presents an artificial neural network (ANN) based approach to tune the parameters of the static var compensator (SVC) reactive power controller over a wide range of typical load model parameters. The gains of PI (proportional integral) based SVC are optimised for typical values of the load voltage characteristics (n q ) by conventional techniques. Using the generated data, the method of multi-layer feed forward ANN with error back propagation training is employed to tune the parameters of the SVC. An ANN tuned SVC controller has been applied to control the reactive power of a variable slip/speed isolated wind-diesel hybrid power system. It is observed that the maximum deviations of all parameters are more for larger values of n q . It has been shown that initially synchronous generator supplies the reactive power required by the induction generator and/or load, and the latter reactive power is purely supplied by the SVC

  11. Measuring modules for the research of compensators of reactive power with voltage stabilization in MATLAB

    Science.gov (United States)

    Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

    2017-10-01

    A set of mathematical modules was developed for evaluation the energy performance in the research of electrical systems and complexes in the MatLab. In the electrotechnical library SimPowerSystems of the MatLab software, there are no measuring modules of energy coefficients characterizing the quality of electricity and the energy efficiency of electrical apparatus. Modules are designed to calculate energy coefficients characterizing the quality of electricity (current distortion and voltage distortion) and energy efficiency indicators (power factor and efficiency) are presented. There are described the methods and principles of building the modules. The detailed schemes of modules built on the elements of the Simulink Library are presented, in this connection, these modules are compatible with mathematical models of electrical systems and complexes in the MatLab. Also there are presented the results of the testing of the developed modules and the results of their verification on the schemes that have analytical expressions of energy indicators.

  12. Quantitative Models and Analysis for Reactive Systems

    DEFF Research Database (Denmark)

    Thrane, Claus

    The majority of modern software and hardware systems are reactive systems, where input provided by the user (possibly another system) and the output of the system is exchanged continuously throughout the (possibly) indefinite execution of the system. Natural examples include control systems, mobi......, energy consumption, latency, mean-time to failure, and cost. For systems integrated in mass-market products, the ability to quantify trade-offs between performance and robustness, under given technical and economic constraints, is of strategic importance....... by the environment in which they are embedded. This thesis studies the semantics and properties of a model-based framework for re- active systems, in which models and specifications are assumed to contain quantifiable information, such as references to time or energy. Our goal is to develop a theory of approximation......, in terms of a new mathematical basis for systems modeling which can incompas behavioural properties as well as environmental constraints. They continue by pointing out that, continuous performance and robustness measures are paramount when dealing with physical resource levels such as clock frequency...

  13. Development of a robust model-based reactivity control system

    International Nuclear Information System (INIS)

    Rovere, L.A.; Otaduy, P.J.; Brittain, C.R.

    1990-01-01

    This paper describes the development and implementation of a digital model-based reactivity control system that incorporates a knowledge of the plant physics into the control algorithm to improve system performance. This controller is composed of a model-based module and modified proportional-integral-derivative (PID) module. The model-based module has an estimation component to synthesize unmeasurable process variables that are necessary for the control action computation. These estimated variables, besides being used within the control algorithm, will be used for diagnostic purposes by a supervisory control system under development. The PID module compensates for inaccuracies in model coefficients by supplementing the model-based output with a correction term that eliminates any demand tracking or steady state errors. This control algorithm has been applied to develop controllers for a simulation of liquid metal reactors in a multimodular plant. It has shown its capability to track demands in neutron power much more accurately than conventional controllers, reducing overshoots to almost negligible value while providing a good degree of robustness to unmodeled dynamics. 10 refs., 4 figs

  14. Reactive extraction at liquid-liquid systems

    Science.gov (United States)

    Wieszczycka, Karolina

    2018-01-01

    The chapter summarizes the state of knowledge about a metal transport in two-phase system. The first part of this review focuses on the distribution law and main factors determination in classical solvent extraction (solubility and polarity of the solute, as well as inter- and intramolecules interaction. Next part of the chapter is devoted to the reactive solvent extraction and the molecular modeling requiring knowledge on type of extractants, complexation mechanisms, metals ions speciation and oxidation during complexes forming, and other parameters that enable to understand the extraction process. Also the kinetic data that is needed for proper modeling, simulation and design of processes needed for critical separations are discussed. Extraction at liquid-solid system using solvent impregnated resins is partially identical as in the case of the corresponding solvent extraction, therefore this subject was also presented in all aspects of separation process (equilibrium, mechanism, kinetics).

  15. Sweden: Autonomous Reactivity Control (ARC) Systems

    International Nuclear Information System (INIS)

    Qvist, Staffan A.

    2015-01-01

    The next generation of nuclear energy systems must be licensed, constructed, and operated in a manner that will provide a competitively priced supply of energy, keeping in consideration an optimum use of natural resources, while addressing nuclear safety, waste, and proliferation resistance, and the public perception concerns of the countries in which those systems are deployed. These issues are tightly interconnected, and the implementation of passive and inherent safety features is a high priority in all modern reactor designs since it helps to tackle many of the issues at once. To this end, the Autonomous Reactivity Control (ARC) system was developed to ensure excellent inherent safety performance of Generation-IV reactors while having a minimal impact on core performance and economic viability. This paper covers the principles for ARC system design and analysis, the problem of ensuring ARC system response stability and gives examples of the impact of installing ARC systems in well-known fast reactor core systems. It is shown that even with a relatively modest ARC installation, having a near-negligible impact on core performance during standard operation, cores such as the European Sodium Fast Reactor (ESFR) can be made to survive any postulated unprotected transient without coolant boiling or fuel melting

  16. Reactive Software Agent Anesthesia Decision Support System

    Directory of Open Access Journals (Sweden)

    Grant H. Kruger

    2011-12-01

    Full Text Available Information overload of the anesthesiologist through technological advances have threatened the safety of patients under anesthesia in the operating room (OR. Traditional monitoring and alarm systems provide independent, spatially distributed indices of patient physiological state. This creates the potential to distract caregivers from direct patient care tasks. To address this situation, a novel reactive agent decision support system with graphical human machine interface was developed. The system integrates the disparate data sources available in the operating room, passes the data though a decision matrix comprising a deterministic physiologic rule base established through medical research. Patient care is improved by effecting change to the care environment by displaying risk factors and alerts as an intuitive color coded animation. The system presents a unified, contextually appropriate snapshot of the patient state including current and potential risk factors, and alerts of critical patient events to the operating room team without requiring any user intervention. To validate the efficacy of the system, a retrospective analysis focusing on the hypotension rules were performed. Results show that even with vigilant and highly trained clinicians, deviations from ideal patient care exist and it is here that the proposed system may allow more standardized and improved patient care and potentially outcomes.

  17. Compensation of distributed delays in integrated communication and control systems

    Science.gov (United States)

    Ray, Asok; Luck, Rogelio

    1991-01-01

    The concept, analysis, implementation, and verification of a method for compensating delays that are distributed between the sensors, controller, and actuators within a control loop are discussed. With the objective of mitigating the detrimental effects of these network induced delays, a predictor-controller algorithm was formulated and analyzed. Robustness of the delay compensation algorithm was investigated relative to parametric uncertainties in plant modeling. The delay compensator was experimentally verified on an IEEE 802.4 network testbed for velocity control of a DC servomotor.

  18. Research on the critical parameters initialization of optical PMD compensator in high bit-rate systems

    Science.gov (United States)

    Zhao, Wenyu; Zhang, Haiyi; Ji, Yuefeng; Xu, Daxiong

    2004-05-01

    Based on the proposed polarization mode dispersion (PMD) compensation simulation model and statistical analysis method (Monte-Carlo), the critical parameters initialization of two typical optical domain PMD compensators, which include optical PMD method with fixed compensation differential group delay (DGD) and that with variable compensation DGD, are detailedly investigated by numerical method. In the simulation, the line PMD values are chosen as 3ps, 4ps and 5ps and run samples are set to 1000 in order to achieve statistical evaluation for PMD compensated systems, respectively. The simulation results show that for the PMD value pre-known systems, the value of the fixed DGD compensator should be set to 1.5~1.6 times of line PMD value in order to reach the optimum performance, but for the second kind of PMD compensator, the DGD range of lower limit should be 1.5~1.6 times of line PMD provided that of upper limit is set to 3 times of line PMD, if no effective ways are chosen to resolve the problem of local minimum in optimum process. Another conclusion can be drawn from the simulation is that, although the second PMD compensator holds higher PMD compensation performance, it will spend more feedback loops to look up the optimum DGD value in the real PMD compensation realization, and this will bring more requirements on adjustable DGD device, not only wider adjustable range, but rapid adjusting speed for real time PMD equalization.

  19. On Barbs and Labels in Reactive Systems

    Directory of Open Access Journals (Sweden)

    Filippo Bonchi

    2010-02-01

    Full Text Available Reactive systems (RSs represent a meta-framework aimed at deriving behavioral congruences for those computational formalisms whose operational semantics is provided by reduction rules. RSs proved a flexible specification device, yet so far most of the efforts dealing with their behavioural semantics focused on idem pushouts (IPOs and saturated (also known as dynamic bisimulations. In this paper we introduce a novel, intermediate behavioural equivalence: L-bisimilarity, which is able to recast both its IPO and saturated counterparts. The equivalence is parametric with respect to a set L of RSs labels, and it is shown that under mild conditions on L it is indeed a congruence. Furthermore, L-bisimilarity can also recast the notion of barbed semantics for RSs, proposed by the same authors in a previous paper. In order to provide a suitable test-bed, we instantiate our proposal by addressing the semantics of (asynchronous CCS and of the calculus of mobile ambients.

  20. Vector spot compensation applied in a CNC system for laser cutting machine

    Science.gov (United States)

    Xie, Qiong; Li, Shimin; Xu, Zhene; Wu, Heqing; Yin, Quan

    1999-09-01

    The vector spot compensation (VSP) is discussed in CNC system for laser cutting machine. The accuracy of laser cutting will be improved by VSP. The modularized vector algorithm which is different from that of traditional geometry algorithm not only unites the symbol system and simplifies the programming complexity, but also improves the spot compensation speed and offers the essential data for the spline interpolation.

  1. [The new financial compensation system PEPP: an ethical analysis].

    Science.gov (United States)

    Vollmann, J

    2014-11-01

    The new compensation system for psychiatric and psychosomatic institutions (German acronym: PEPP) not only constitutes a change in billing practices, but also necessitates an ethical investigation and analysis of possible consequences of the new legislation for those affected in practice. Following the presentation of the new PEPP and its consequences for psychiatric practice, problems and areas of conflict will be analyzed from an ethical perspective and discussed. Ethical conflicts exist in the following areas: (1) in the attempt to standardize inpatient care and invoicing for mental illnesses, (2) in poorer treatment for severely ill patients in view of degressive per diem rates, (3) in false incentives due to threshold values e.g. for 1:1 health professional-patient ratios in the case of coercive measures and (4) due to the inappropriate use of a supposed normative neutral quantitative economic model for a qualitative work area that often takes place in human border zones such as complex inpatient care of severely mentally ill patients. The ethical analysis of PEPP reveals that apart from the limited opportunities to improve efficiency, there is a considerable ethical risk of loss of quality in psychiatric inpatient care in particular for severely and chronically mentally ill patients.

  2. Reactive power control and optimisation of hybrid off shore tidal turbine with system uncertainties

    Directory of Open Access Journals (Sweden)

    Asit Mohanty

    2016-12-01

    Full Text Available This paper projects an isolated hybrid model of Offshore wind-diesel-tidal turbine and discusses the stability and reactive power management issue of the whole system. The hybrid system often loses its stability as it becomes prone to uncertain load and input parameters and therefore the necessity of Reactive power management becomes necessary. The overall stability of the hybrid offshore wind-diesel-tidal turbine is made possible by the management of reactive power in the hybrid system through the application of FACTS devices. And therefore the dynamic hybrid model of the DFIG and DDPMSG based offshore wind-diesel-tidal turbine is analysed for stability with different input parameters like wind and tidal energies. For detailed modelling and simulation, a small signal model of the whole hybrid system is designed and reactive power management of the system is achieved by the incorporation of a STATCOM controller. For improvement of stability and reactive power compensation of the hybrid system, GA and PSO optimised STATCOM controller is used.

  3. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  4. A design method of compensators for multi-variable control system with PID controllers 'CHARLY'

    International Nuclear Information System (INIS)

    Fujiwara, Toshitaka; Yamada, Katsumi

    1985-01-01

    A systematic design method of compensators for a multi-variable control system having usual PID controllers in its loops is presented in this paper. The method itself is able: to determine the main manipulating variable corresponding to each controlled variable with a sensitivity analysis in the frequency domain. to tune PID controllers sufficiently to realize adequate control actions with a searching technique of minimum values of cost functionals. to design compensators improving the control preformance and to simulate a total system for confirming the designed compensators. In the phase of compensator design, the state variable feed-back gain is obtained by means of the OPTIMAL REGULATOR THEORY for the composite system of plant and PID controllers. The transfer function type compensators the configurations of which were previously given are, then, designed to approximate the frequency responces of the above mentioned state feed-back system. An example is illustrated for convenience. (author)

  5. Simulation and Analysis of Passive Rolling Compensation of High Sea Salvage System

    Directory of Open Access Journals (Sweden)

    Lin Liqun

    2017-01-01

    Full Text Available Method and device of a flexible interception and salvage system was introduced in this paper. In order to study the effect of wave motion on salvage operation, we proposed a passive wave compensation scheme that utilizes a combination of variable-pitch cylinders and accumulators, and established the mathematical vibration model of the rolling motion of the salvage compensation system. With the relationships between the stiffness coefficient and the accumulator parametric of passive compensated gas-liquid system, we determined the effective compensation stiffness range through Mathematica simulation analysis. The relationship between the roll displacement of the salvage arm and the initial volume Vo of the accumulator has been analysed. The results show that the accumulatorVo in a certain range has a great influence on the passive compensation. However, when the volume is greater than 20m3, the compensation effect is weakened, and tend to a certain value, irrespective of the passive system accumulator volume capacity, it does not achieve full compensation. The results have important guidance on the design and optimization of rolling passive compensation of the practical high sea salvage system.

  6. Robust finite-time tracking control for nonlinear suspension systems via disturbance compensation

    Science.gov (United States)

    Pan, Huihui; Jing, Xingjian; Sun, Weichao

    2017-05-01

    This paper focuses on the finite-time tracking control with external disturbance for active suspension systems. In order to compensate unknown disturbance efficiently, a disturbance compensator with finite-time convergence property is studied. By analyzing the discontinuous phenomenon of classical disturbance compensation techniques, this study presents a simple approach to construct a continuous compensator satisfying the finite-time disturbance rejection performance. According to the finite-time separation principle, the design procedures of the nominal controller for the suspension system without disturbance and the disturbance compensator can be implemented in a completely independent manner. Therefore, the overall control law for the closed-loop system is continuous, which offers some distinct advantages over the existing discontinuous ones. From the perspective of practical implementation, the continuous controller can avoid effectively the unexpected chattering in active suspension control. Comparative experimental results are presented and discussed to illustrate the advantage and effectiveness of the proposed control strategy.

  7. Actinide and Xenon reactivity effects in ATW high flux systems

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, M. [Univ. of Virginia, Charlottesville, VA (United States); Olson, K.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)] [and others

    1995-10-01

    In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

  8. Actinide and xenon reactivity effects in ATW high flux systems

    International Nuclear Information System (INIS)

    Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C.

    1995-01-01

    In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

  9. Actinide and Xenon reactivity effects in ATW high flux systems

    International Nuclear Information System (INIS)

    Woosley, M.; Olson, K.; Henderson, D.L.

    1995-01-01

    In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

  10. Application of an evolutionary algorithm in the reactive compensation of transmission networks of electrical energy planning; Aplicacion de un algoritmo evolutivo en la planificacion de la compensacion reactiva de redes de transmision de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Galicia, Julio A.; Nieva Gomez, Rolando [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In the present work it is considered the mathematical formulation of the problem of the reactive compensation planning, The solution technique based on evolutionary programming is described and the results of compensation in the Northwest subsystem of the Mexican electrical system are shown. A technique of optimization based on the Evolutionary Programming is proposed to solve the problem of the Planning of the Reactive Compensation in transmission of electrical energy networks. The problem consists in determining how much compensation to add and where to locate it in such a way that the investment cost of the compensation equipment is diminished, plus the operation costs associated to the transmission losses, plus a penalty function associated to the violations of the operative limits of voltage. The compensation that is determined must allow that the network operates in normal conditions before any contingency of a pre-established assembly. The problem considered is non-linear and whole compound. Tests made to a representative system of the Northwest area of the Mexican electrical system of 171 nodes and 284 branches are reported. [Spanish] En el presente trabajo se plantea la formulacion matematica del problema de planificacion de la compensacion reactiva, se describe la tecnica de solucion basada en programacion evolutiva y se muestra resultados de compensacion en el subsistema Noroeste del sistema electrico mexicano. Se propone una tecnica de optimizacion basada en la Programacion Evolutiva para resolver el problema de la Planificacion de la Compensacion Reactiva en redes de transmision de energia electrica. El problema consiste en determinar cuanta compensacion agregar y donde ubicarla de tal manera que se minimice el costo de inversion del equipo de compensacion, mas los costos de operacion asociados a las perdidas de transmision, mas una funcion de penalizacion asociada a la violaciones de los limites operativos de voltaje. La compensacion que se determine

  11. Distributed Reactive Power Control based Conservation Voltage Reduction in Active Distribution Systems

    Directory of Open Access Journals (Sweden)

    EMIROGLU, S.

    2017-11-01

    Full Text Available This paper proposes a distributed reactive power control based approach to deploy Volt/VAr optimization (VVO / Conservation Voltage Reduction (CVR algorithm in a distribution network with distributed generations (DG units and distribution static synchronous compensators (D-STATCOM. A three-phase VVO/CVR problem is formulated and the reactive power references of D-STATCOMs and DGs are determined in a distributed way by decomposing the VVO/CVR problem into voltage and reactive power control. The main purpose is to determine the coordination between voltage regulator (VR and reactive power sources (Capacitors, D-STATCOMs and DGs based on VVO/CVR. The study shows that the reactive power injection capability of DG units may play an important role in VVO/CVR. In addition, it is shown that the coordination of VR and reactive power sources does not only save more energy and power but also reduces the power losses. Moreover, the proposed VVO/CVR algorithm reduces the computational burden and finds fast solutions. To illustrate the effectiveness of the proposed method, the VVO/CVR is performed on the IEEE 13-node test system feeder considering unbalanced loading and line configurations. The tests are performed taking the practical voltage-dependent load modeling and different customer types into consideration to improve accuracy.

  12. Rigorous method for compensation selection and alignment of microlithographic optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, H.N.; Sweeney, D.W.

    1998-03-25

    The assembly of an optical system requires the correction of aberrations in the entire imaging field by making selected rigid-body motions of the optical elements. We present a rigorous method for determining which adjustment motions, called compensators, to use for alignment. These compensators are found by employing techniques from linear algebra that choose the most independent vectors from a set which are interdependent. The method finds the smallest number of compensators to correct for misalignments of a given magnitude. As an example the method is applied to a four-mirror scanning ring-field EUV lithography system. It is shown that out of 32 degrees of freedom in the configuration of the optical elements, only eight compensators are required on the optics. By adjusting these compensators a misaligned configuration giving a 30 {lambda} wavefront error can be assembled to {lambda}/50 in the absence of measurement noise.

  13. Verification and compensation of respiratory motion using an ultrasound imaging system.

    Science.gov (United States)

    Chuang, Ho-Chiao; Hsu, Hsiao-Yu; Chiu, Wei-Hung; Tien, Der-Chi; Wu, Ren-Hong; Hsu, Chung-Hsien

    2015-03-01

    The purpose of this study was to determine if it is feasible to use ultrasound imaging as an aid for moving the treatment couch during diagnosis and treatment procedures associated with radiation therapy, in order to offset organ displacement caused by respiratory motion. A noninvasive ultrasound system was used to replace the C-arm device during diagnosis and treatment with the aims of reducing the x-ray radiation dose on the human body while simultaneously being able to monitor organ displacements. This study used a proposed respiratory compensating system combined with an ultrasound imaging system to monitor the compensation effect of respiratory motion. The accuracy of the compensation effect was verified by fluoroscopy, which means that fluoroscopy could be replaced so as to reduce unnecessary radiation dose on patients. A respiratory simulation system was used to simulate the respiratory motion of the human abdomen and a strain gauge (respiratory signal acquisition device) was used to capture the simulated respiratory signals. The target displacements could be detected by an ultrasound probe and used as a reference for adjusting the gain value of the respiratory signal used by the respiratory compensating system. This ensured that the amplitude of the respiratory compensation signal was a faithful representation of the target displacement. The results show that performing respiratory compensation with the assistance of the ultrasound images reduced the compensation error of the respiratory compensating system to 0.81-2.92 mm, both for sine-wave input signals with amplitudes of 5, 10, and 15 mm, and human respiratory signals; this represented compensation of the respiratory motion by up to 92.48%. In addition, the respiratory signals of 10 patients were captured in clinical trials, while their diaphragm displacements were observed simultaneously using ultrasound. Using the respiratory compensating system to offset, the diaphragm displacement resulted in

  14. In defense of a regulated system of compensation for living donation.

    Science.gov (United States)

    Matas, Arthur J; Hippen, Benjamin; Satel, Sally

    2008-08-01

    The organ shortage is the major problem in kidney transplantation today. Despite aggressive organ procurement efforts, the supply of donated kidneys, living and deceased, has not matched the growing demand; as a consequence, more and more qualified candidates are suffering on dialysis and then dying before being transplanted. Herein, we provide justification for a regulated system of compensation for donation. The main argument in favor of compensation is simple-financial incentives will increase donation, so fewer transplant candidates will suffer and die while waiting. In addition, development of a regulated system of compensation is the most effective means of crippling the core economic support for transplant tourism. Because dialysis is so much more expensive than a transplant, compensated donation could be cost-neutral to the healthcare system. Importantly, opinion polls suggest that the public would support compensation. As uncompensated kidney donation is widely accepted, persuasive arguments against compensation must explain why such a system would be morally distinguishable from uncompensated donation. We suggest that the potential advantages of a regulated system of compensation for donation far outweigh any potential disadvantages. It is time to advocate for a change in the law so that trials can be done.

  15. Study on APD real time compensation methods of laser Detection system

    Science.gov (United States)

    Ying, Feng; He, Zhang; Xiangjin, Zhang; Kun, Liu

    2011-02-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained by analyzing

  16. New Adaptive Method for IQ Imbalance Compensation of Quadrature Modulators in Predistortion Systems

    Directory of Open Access Journals (Sweden)

    Hassan Zareian

    2009-01-01

    Full Text Available Imperfections in quadrature modulators (QMs, such as inphase and quadrature (IQ imbalance, can severely impact the performance of power amplifier (PA linearization systems, in particular in adaptive digital predistorters (PDs. In this paper, we first analyze the effect of IQ imbalance on the performance of a memory orthogonal polynomials predistorter (MOP PD, and then we propose a new adaptive algorithm to estimate and compensate the unknown IQ imbalance in QM. Unlike previous compensation techniques, the proposed method was capable of online IQ imbalance compensation with faster convergence, and no special calibration or training signals were needed. The effectiveness of the proposed IQ imbalance compensator was validated by simulations. The results clearly show the performance of the MOP PD to be enhanced significantly by adding the proposed IQ imbalance compensator.

  17. A Study on Employees' Perception towards Compensation Management System in Selected Branches of SBI of Ujjain District

    OpenAIRE

    Harish Shukla; Shweta Tiwari

    2013-01-01

    Employee satisfaction is one of the most important aspects in the organization that cannot be ensured without proper compensation management system. The present work is based on the study of Compensation Management System in selected branches of SBI. SBI being the largest nationalized bank needs strong compensation management systems so that it can achieve rapid growth at national as well as international level. The study aims at knowing whether current compensation policy is able to attract,...

  18. Reactive oxygen species and the cardiovascular system

    NARCIS (Netherlands)

    Y.J.H.J. Taverne (Yannick); A.J.J.C. Bogers (Ad); D.J.G.M. Duncker (Dirk); D. Merkus (Daphne)

    2013-01-01

    textabstractEver since the discovery of free radicals, many hypotheses on the deleterious actions of reactive oxygen species (ROS) have been proposed. However, increasing evidence advocates the necessity of ROS for cellular homeostasis. ROS are generated as inherent by-products of aerobic metabolism

  19. A reactive data structure for geographic information systems

    NARCIS (Netherlands)

    Oosterom, P.J.M. van

    1989-01-01

    We introduce a Reactive Data Structure, that is a spatial data structure with detail levels. The two properties, spatial organization and detail levels, are the basis for a Geographic Information System with a multi-scale database. A reactive data structure is a novel type of data structure catering

  20. Reactivity Monitoring of Accelerator-Driven Nuclear Reactor Systems

    NARCIS (Netherlands)

    Uyttenhove, W.

    2016-01-01

    This thesis provides a methodology and set-up of a reactivity monitoring tool for Accelerator-Driven Systems (ADS). The reactivity monitoring tool should guarantee the operation of an ADS at a safe margin from criticality. Robustness is assured in different aspects of the monitoring tool: the choice

  1. Adaptive Harmonic Compensation in Residential Distribution Grid by Roof-Top PV Systems

    DEFF Research Database (Denmark)

    Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

    2018-01-01

    Fourier Transform (SDFT) algorithm and then individually compensate the measured harmonics by the proposed adaptive harmonic compensator. In the proposed approach, a current reference is separately determined for compensating each harmonic component. Then, a specific amount of additional current capacity...... grid- connected roof-top PV inverters in residential distribution grid can be an opportunity to engage these systems in the power quality issues as custom power devices. By implementing a proper control for roof-top PV inverters, these systems may in addition to inject the fundamental current......, additionally act like a virtual harmonic resistance and dedicate their additional current capacity to compensate the harmonics of residential distribution grid. In this paper, each roof-top PV system is a grid harmonic supervisor, where it continually measures the PCC voltage harmonics by Sliding Discrete...

  2. A dimension reduction method for flood compensation operation of multi-reservoir system

    Science.gov (United States)

    Jia, B.; Wu, S.; Fan, Z.

    2017-12-01

    Multiple reservoirs cooperation compensation operations coping with uncontrolled flood play vital role in real-time flood mitigation. This paper come up with a reservoir flood compensation operation index (ResFCOI), which formed by elements of flood control storage, flood inflow volume, flood transmission time and cooperation operations period, then establish a flood cooperation compensation operations model of multi-reservoir system, according to the ResFCOI to determine a computational order of each reservoir, and lastly the differential evolution algorithm is implemented for computing single reservoir flood compensation optimization in turn, so that a dimension reduction method is formed to reduce computational complexity. Shiguan River Basin with two large reservoirs and an extensive uncontrolled flood area, is used as a case study, results show that (a) reservoirs' flood discharges and the uncontrolled flood are superimposed at Jiangjiaji Station, while the formed flood peak flow is as small as possible; (b) cooperation compensation operations slightly increase in usage of flood storage capacity in reservoirs, when comparing to rule-based operations; (c) it takes 50 seconds in average when computing a cooperation compensation operations scheme. The dimension reduction method to guide flood compensation operations of multi-reservoir system, can make each reservoir adjust its flood discharge strategy dynamically according to the uncontrolled flood magnitude and pattern, so as to mitigate the downstream flood disaster.

  3. Investigation of the behavior of a three phase grid-connected photovoltaic system to control active and reactive power

    Energy Technology Data Exchange (ETDEWEB)

    Tsengenes, Georgios; Adamidis, Georgios [Department of Electrical Engineering and Computer Engineering, Democritus University of Thrace, University Campus Kimmeria, 67100 Xanthi (Greece)

    2011-01-15

    In this paper, a photovoltaic (PV) system, with maximum power point tracking (MPPT), connected to a three phase grid is presented. The connection of photovoltaic system on the grid takes place in one stage using voltage source inverter (VSI). For a better utilization of the photovoltaic system, the control strategy applied is based on p-q theory. According to this strategy during sunlight the system sends active power to the grid and at the same time compensates the reactive power of the load. In case there is no sunlight (during the night for instance), the inverter only compensates the reactive power of the load. In this paper the use of p-q theory to supply the grid with active power and compensate the reactive power of the load is investigated. The advantage of this control strategy is that the photovoltaic system is operated the whole day. Furthermore, the p-q theory uses simple algebraic calculations without demanding the use of PLL to synchronize the inverter with the grid. (author)

  4. Self-enhancement and cardiovascular reactivity: limitations of the hemodynamic profile-compensation deficit (HP-CD) model of blood pressure regulation.

    Science.gov (United States)

    Why, Yong Peng; Chen, Maximillian Ruyang

    2013-02-01

    We examined the consistency of results obtained when examining the relationship between self-enhancement and cardiovascular reactivity via analysing raw cardiovascular data and compared this with the hemodynamic profile-compensation deficit (HP-CD) model of blood pressure regulation (James et al., 2012) method. A sample of 112 male participants underwent a computer-based task three times in three weeks. Our results indicate that significant results for self-enhancement and hemodynamic cardiovascular reactivity found using raw cardiovascular data were non-significant when HP-CD model was used. Furthermore, the HP-CD model also obfuscates significant baseline changes with reactivity. We also found that the correlations between blood pressure reactivity and hemodynamic processes obtained in the laboratory setting was reduced rather than enhanced with the use of the HP-CD model. Our results suggest that the HP-CD model should be used cautiously and could contribute to inconsistent results when examining the role of psychological factors in biological outcomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Is clinician refusal to treat an emerging problem in injury compensation systems?

    Science.gov (United States)

    Brijnath, Bianca; Mazza, Danielle; Kosny, Agnieszka; Bunzli, Samantha; Singh, Nabita; Ruseckaite, Rasa; Collie, Alex

    2016-01-20

    The reasons that doctors may refuse or be reluctant to treat have not been widely explored in the medical literature. To understand the ethical implications of reluctance to treat there is a need to recognise the constraints of doctors working in complex systems and to consider how these constraints may influence reluctance. The aim of this paper is to illustrate these constraints using the case of compensable injury in the Australian context. Between September and December 2012, a qualitative investigation involving face-to-face semistructured interviews examined the knowledge, attitudes and practices of general practitioners (GPs) facilitating return to work in people with compensable injuries. Compensable injury management in general practice in Melbourne, Australia. 25 GPs who were treating, or had treated a patient with compensable injury. The practice of clinicians refusing treatment was described by all participants. While most GPs reported refusal to treat among their colleagues in primary and specialist care, many participants also described their own reluctance to treat people with compensable injuries. Reasons offered included time and financial burdens, in addition to the clinical complexities involved in compensable injury management. In the case of compensable injury management, reluctance and refusal to treat is likely to have a domino effect by increasing the time and financial burden of clinically complex patients on the remaining clinicians. This may present a significant challenge to an effective, sustainable compensation system. Urgent research is needed to understand the extent and implications of reluctance and refusal to treat and to identify strategies to engage clinicians in treating people with compensable injuries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Reactive power static sources in the diagnosis of insulation condition of the induction motor and the power supply cable in terms of local compensation

    Directory of Open Access Journals (Sweden)

    Валерій Єгорович Кривоносов

    2017-06-01

    Full Text Available Reactive power compensation is particularly relevant for the industrial companies, major power consumers of which are asynchronous motors (АM. The most effective reactive power compensation is at placing the capacitor bank (CB directly at the points of AM connection. The capacity of the CB and the method of controlling the power factor depend on the AM loading conditions. Under operating conditions ensuring AM reliable start-up after a technological pause is an important task. Reliable motor start-up is possible when the insulation resistance of the stator windings is equal to or above 0.5 megohms. The discharge of the capacitor bank at the moment of the AM disconnection from the network, makes it possible to use the power stored in the CB to diagnose insulation condition and suitability of the AM to a safe start. The speed of the CB discharge is the criterion showing that the AM winding insulation resistance is of critical value. The capacitors discharge simulation made it possible to develop a method to protect the AM and the power cable as well as to formulate an algorithm to identify one-, two-, three- and interphase short circuit when operating, and at the time of the AM disconnection from the network and to define the critical value of the insulation resistance according to the capacitor discharge speed

  7. Techniques for reactive system design: the tools in TRADE

    NARCIS (Netherlands)

    Wieringa, Roelf J.; Jansen, D.N.; Dittrich, K.R.; Geppert, A.; Norrie, M.C.

    Reactive systems are systems whose purpose is to maintain a certain desirable state of affairs in their environment, and include information systems, groupware, workflow systems, and control software. The current generation of information system design methods cannot cope with the high demands that

  8. Two-frequency, one-detector reactivity system (TFODRS)

    International Nuclear Information System (INIS)

    Sachs, R.D.; Woodall, D.M.

    1985-01-01

    A two-frequency, one-detector reactivity system (TFODRS) was experimentally verified on the University of New Mexico (UNM) AGN-201M thermal reactor. That system was used to obtain the absolute steady-state reactivity and to demonstrate the feasibility of acquiring the transient reactivity. A detailed description of TFODRS hardware and software is given in this paper. The TFODRS obtains the absolute and net reactivity by computing the frequency spectrum of the reactor neutron-detector signal. The ratio of the high-frequency to the low-frequency components about an empirical break point is used to determine the reactivity. The TFODRS was successfully used to measure a known AGN-201M steady-state reactivity, with a relative error of 18%. TFODRS transient curves as a function of reactivity were shown to be different from the steady-state curves. The transient curves appear to be a function of the rate of reactivity insertion. The authors speculate that a modified TFODRS, using state-of-the-art microprocessors, could be used for fast reactors. The TFODRS is not presently a practicable reactimeter. However, with more research and development, it is felt it could be used in near-term nuclear industry applications, such as monitoring fuel storage pools

  9. Bias-Compensated Normalized Maximum Correntropy Criterion Algorithm for System Identification with Noisy Input

    OpenAIRE

    Ma, Wentao; Zheng, Dongqiao; Li, Yuanhao; Zhang, Zhiyu; Chen, Badong

    2017-01-01

    This paper proposed a bias-compensated normalized maximum correntropy criterion (BCNMCC) algorithm charactered by its low steady-state misalignment for system identification with noisy input in an impulsive output noise environment. The normalized maximum correntropy criterion (NMCC) is derived from a correntropy based cost function, which is rather robust with respect to impulsive noises. To deal with the noisy input, we introduce a bias-compensated vector (BCV) to the NMCC algorithm, and th...

  10. Reactive In-flight Multisensor Security System (RIMSS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for in-flight event detection and monitoring systems is clear. To address this and other safety and security needs, IEM proposed the Reactive In-flight...

  11. Refractive Index Compensation in Over-Determined Interferometric Systems

    Directory of Open Access Journals (Sweden)

    Zdeněk Buchta

    2012-10-01

    Full Text Available We present an interferometric technique based on a differential interferometry setup for measurement under atmospheric conditions. The key limiting factor in any interferometric dimensional measurement are fluctuations of the refractive index of air representing a dominating source of uncertainty when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of an over-determined interferometric setup where a reference length is derived from a mechanical frame made from a material with a very low thermal coefficient. The technique allows one to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range, acting as a tracking refractometer. The principle is demonstrated in an experimental setup.

  12. Compensación de la potencia reactiva en sistemas de baja tensión mediante bancos de capacitores fijos, utilizando algoritmos genéticos; Reactive compensation in low voltaje power systems with fixed capaciyors banks using genetic algorithms

    Directory of Open Access Journals (Sweden)

    Davel Borges Vasconcellos

    2011-05-01

    Full Text Available Una óptima selección de estos, presupone tres aspectos: la selección de la capacidad de los bancos, el tipo de compensador a utilizar, así como la ubicación en el sistema eléctrico de baja tensión Existen referencias de métodos que consideran los tres aspectos de manera conjunta, basados en la programación matemática, pero estos presentan limitantes dado que no pueden representar todos los efectos de la compensación y se basan en técnicas de programación continua, siendo este un problema de optimización complejo de espacio de búsqueda discreto.En tal sentido, hemos desarrollado un método con el empleo de los algoritmos genéticos que posibilita una formulación más exacta del problema. El método ha sido programado con ayuda del MATLAB, versión 7.5 (R2007b, utilizando las estructuras de programación de Genetic Algorithm and Direct Search Toolbox. La efectividad del mismo se muestra en un ejemplo real de aplicación al sistema eléctrico de baja tensión de una instalación hotelera del Grupo Cubanacan de la provincia de Camagüey.  A good selection of these, presupposes three aspects: the selection of the banks capacity, the compensador type to use, as well as the location in the low voltage system.References of methods that consider the three aspects in a same problem are based on the mathematical programming, but these cannot represent all the effects of the compensation and these based in technical of continuous programming, being this a complex optimization problem of discreet search space.In the paper, we have developed a method with the employment of the genetic algorithms, which facilitates a more exact problem formulation. The method has been programmed in MATLAB, version 7.5 (R2007b, using programming structures of Genetic Algorithm and Direct Search Toolbox.The effectiveness is shown in an example of real application to the low voltage system of a hotel installation of the Cubanacan Company in Camagüey.

  13. Differences in perceived fairness and health outcomes in two injury compensation systems: a comparative study

    Directory of Open Access Journals (Sweden)

    Nieke A. Elbers

    2016-07-01

    Full Text Available Abstract Background Involvement in a compensation process following a motor vehicle collision is consistently associated with worse health status but the reasons underlying this are unclear. Some compensation systems are hypothesised to be more stressful than others. In particular, fault-based compensation systems are considered to be more adversarial than no-fault systems and associated with poorer recovery. This study compares the perceived fairness and recovery of claimants in the fault-based compensation system in New South Wales (NSW to the no-fault system in Victoria, Australia. Methods One hundred eighty two participants were recruited via claims databases of the compensation system regulators in Victoria and NSW. Participants were > 18 years old and involved in a transport injury compensation process. The crash occurred 12 months (n = 95 or 24 months ago (n = 87. Perceived fairness about the compensation process was measured by items derived from a validated organisational justice questionnaire. Health outcome was measured by the initial question of the Short Form Health Survey. Results In Victoria, 84 % of the participants considered the claims process fair, compared to 46 % of NSW participants (χ2 = 28.54; p < .001. Lawyer involvement and medical assessments were significantly associated with poorer perceived fairness. Overall perceived fairness was positively associated with health outcome after adjusting for demographic and injury variables (Adjusted Odds Ratio = 2.8, 95 % CI = 1.4 – 5.7, p = .004. Conclusion The study shows large differences in perceived fairness between two different compensation systems and an association between fairness and health. These findings are politically important because compensation processes are designed to improve recovery. Lower perceived fairness in NSW may have been caused by potential adversarial aspects of the scheme, such as liability assessment, medical

  14. Compensating Victims of Mass Disasters Through the Court System: Procedural Challenges and Innovations

    Directory of Open Access Journals (Sweden)

    Edward Sherman

    2013-01-01

    Full Text Available How best to compensate victims of mass disasters – whether made by man or nature – is a worldwide problem. This article considers the very different approaches in three recent U.S. disasters. In the 2001 9/11 terrorist bombings, in which the wrong-doers could not reached, the government bore the brunt of the compensation. In the Katrina litigation, where the damage was from the 2005 hurricane, long-term losses had to be recovered through insurance or tort suits, neither of which turned out very satisfactorily for the victims. In the BP Oil Spill litigation, resulting from the 2010 oil spill in the Gulf of Mexico, the court tort system has been the primary source of compensation against BP and its partners that were responsible for the disaster. The ‘claims process’ that has been central to insuring long-term compensation is examined.

  15. Design and Development of Virtual Reactivity System for PWR

    International Nuclear Information System (INIS)

    Anwar, M. I.

    2012-01-01

    The reactivity monitoring and investigation is an important mean to ensure the safety operation of a nuclear power plant. But the reactivity of the nuclear reactor usually cannot be directly measured. It should be computed with certain estimation method. In this thesis, an effort has been made using an artificial neural network and highly fluctuating experimental data for predicting the total reactivity of the nuclear reactor based on all components of net reactivity. This virtual reactivity system is designed by taking advantage of neural network's nonlinear mapping capability. Based on analysis of the reactivity contributing factors, several neural network models are built separately for control rod, boron, poisons, fuel Doppler Effect and moderator effect. Extensive simulation and validation tests for PWR show that satisfied results have been obtained with the proposed approach. It presents a new idea to estimate the PWR's reactivity using artificial intelligence. All the design and simulation work is carried out in MATLAB and a real time programming environment is chosen for the computation and prediction of reactivity. (author)

  16. Reactivation System for Proton-Exchange Membrane Fuel-Cells

    Directory of Open Access Journals (Sweden)

    Roberto Giral

    2012-07-01

    Full Text Available In recent years, Proton-Exchange Membrane Fuel Cells (PEMFCs have been the focus of very intensive researches. Manufacturers of these alternative power sources propose a rejuvenation sequence after the FC has been operating at high power for a certain period of time. These rejuvenation methods could be not appropriate for the reactivation of the FC when it has been out of operation for a long period of time or after it has been repaired. Since the developed reactivation system monitors temperature, current, and the cell voltages of the stack, it could be also useful for the diagnostic and repairing processes. The limited number of published contributions suggests that systems developing reactivation techniques are an open research field. In this paper, an automated system for reactivating PEMFCs and results of experimental testing are presented.

  17. Digital nonlinearity compensation in high-capacity optical communication systems considering signal spectral broadening effect.

    Science.gov (United States)

    Xu, Tianhua; Karanov, Boris; Shevchenko, Nikita A; Lavery, Domaniç; Liga, Gabriele; Killey, Robert I; Bayvel, Polina

    2017-10-11

    Nyquist-spaced transmission and digital signal processing have proved effective in maximising the spectral efficiency and reach of optical communication systems. In these systems, Kerr nonlinearity determines the performance limits, and leads to spectral broadening of the signals propagating in the fibre. Although digital nonlinearity compensation was validated to be promising for mitigating Kerr nonlinearities, the impact of spectral broadening on nonlinearity compensation has never been quantified. In this paper, the performance of multi-channel digital back-propagation (MC-DBP) for compensating fibre nonlinearities in Nyquist-spaced optical communication systems is investigated, when the effect of signal spectral broadening is considered. It is found that accounting for the spectral broadening effect is crucial for achieving the best performance of DBP in both single-channel and multi-channel communication systems, independent of modulation formats used. For multi-channel systems, the degradation of DBP performance due to neglecting the spectral broadening effect in the compensation is more significant for outer channels. Our work also quantified the minimum bandwidths of optical receivers and signal processing devices to ensure the optimal compensation of deterministic nonlinear distortions.

  18. Redundant unbalance compensation of an active magnetic bearing system

    Science.gov (United States)

    Hutterer, Markus; Kalteis, Gerald; Schrödl, Manfred

    2017-09-01

    To achieve a good running behavior of a magnetic levitated rotor, a well-developed position controller and different compensation methods are required. Two very important structures in this context are the reduction of the gyroscopic effect and the unbalance vibration. Both structures have in common that they need the angular velocity information for calculation. For industrial applications this information is normally provided by an angle sensor which is fixed on the rotor. The angle information is also necessary for the field oriented control of the electrical drive. The main drawback of external position sensors are the case of a breakdown or an error of the motor controller. Therefore, the magnetic bearing can get unstable, because no angular velocity information is provided. To overcome this problem the presented paper describes the development of a selfsensing unbalance rejection in combination with a selfsensing speed control of the motor controller. Selfsensing means in this context that no angle sensor is required for the unbalance or torque control. With such structures two redundant speed and angle information sources are available and can be used for the magnetic bearing and the motor controller without the usage of an angle sensor.

  19. Hysteresis and compensation behaviors of spin-3/2 cylindrical Ising nanotube system

    International Nuclear Information System (INIS)

    Kocakaplan, Yusuf; Keskin, Mustafa

    2014-01-01

    The hysteresis and compensation behaviors of the spin-3/2 cylindrical Ising nanotube system are studied within the framework of the effective-field theory with correlations. The effects of the Hamiltonian parameters are investigated on the magnetic and thermodynamic quantities, such as the total magnetization, hysteresis curves, and compensation behaviors of the system. Depending on the Hamiltonian parameters, some characteristic hysteresis behaviors are found, such as the existence of double and triple hysteresis loops. According to Néel classification nomenclature, the system displays Q-, R-, P-, N-, M-, and S- types of compensation behaviors for the appropriate values of the system parameters. We also compare our results with some recently published theoretical and experimental works and find a qualitatively good agreement

  20. Hysteresis and compensation behaviors of spin-3/2 cylindrical Ising nanotube system

    Energy Technology Data Exchange (ETDEWEB)

    Kocakaplan, Yusuf [Graduate School of Natural and Applied Sciences, Erciyes University, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2014-09-07

    The hysteresis and compensation behaviors of the spin-3/2 cylindrical Ising nanotube system are studied within the framework of the effective-field theory with correlations. The effects of the Hamiltonian parameters are investigated on the magnetic and thermodynamic quantities, such as the total magnetization, hysteresis curves, and compensation behaviors of the system. Depending on the Hamiltonian parameters, some characteristic hysteresis behaviors are found, such as the existence of double and triple hysteresis loops. According to Néel classification nomenclature, the system displays Q-, R-, P-, N-, M-, and S- types of compensation behaviors for the appropriate values of the system parameters. We also compare our results with some recently published theoretical and experimental works and find a qualitatively good agreement.

  1. An improved current control scheme for grid-connected DG unit based distribution system harmonic compensation

    DEFF Research Database (Denmark)

    He, Jinwei; Wei Li, Yun; Wang, Xiongfei

    2013-01-01

    In order to utilize DG unit interfacing converters to actively compensate distribution system harmonics, this paper proposes an enhanced current control approach. It seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current...... the fundamental current reference. The proposed power control scheme effectively eliminates the impacts of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated. Experimental results from a single...... controller has two well decoupled control branches to independently control fundamental and harmonic DG currents, phase-locked loops (PLL) and system harmonic component extractions can be avoided during system harmonic compensation. Moreover, a closed-loop power control scheme is also employed to derive...

  2. Initial-beam-loading compensation system for high-intensity electron linacs

    International Nuclear Information System (INIS)

    Satoh, M.; Matsumoto, T.; Shidara, T.; Fukuda, S.; Kobayashi, H.; Kamiya, Y.; Nakamura, N.; Koseki, T.; Miura, S.

    2005-01-01

    We developed an initial-beam-loading compensation system for electron linacs. This system consists of a ΔΦ-A (phase-to-amplitude) modulator and a fast-phase detector. The ΔΦ-A modulator can modulate the phase and the amplitude of a low-power RF simultaneously. Low-power and high-power tests were successfully carried out at KEK. The result of the high-power tests show that our system can reduce the energy spread from 27 to 0.3% for a 300-mA average current. The system that we developed can be a powerful tool for initial-beam-loading compensation. In addition, a numerical calculation method using the power-flow matrix was formulated to perform a fast beam-energy calculation with a simple algorithm. This method can be used to obtain the target RF waveform for energy-spread compensation

  3. Subdivision Error Analysis and Compensation for Photoelectric Angle Encoder in a Telescope Control System

    Directory of Open Access Journals (Sweden)

    Yanrui Su

    2015-01-01

    Full Text Available As the position sensor, photoelectric angle encoder affects the accuracy and stability of telescope control system (TCS. A TCS-based subdivision error compensation method for encoder is proposed. Six types of subdivision error sources are extracted through mathematical expressions of subdivision signals first. Then the period length relationships between subdivision signals and subdivision errors are deduced. And the error compensation algorithm only utilizing the shaft position of TCS is put forward, along with two control models; Model I is that the algorithm applies only to the speed loop of TCS and Model II is applied to both speed loop and position loop. Combined with actual project, elevation jittering phenomenon of the telescope is discussed to decide the necessity of DC-type subdivision error compensation. Low-speed elevation performance before and after error compensation is compared to help decide that Model II is preferred. In contrast to original performance, the maximum position error of the elevation with DC subdivision error compensation is reduced by approximately 47.9% from 1.42″ to 0.74″. The elevation gets a huge decrease in jitters. This method can compensate the encoder subdivision errors effectively and improve the stability of TCS.

  4. A denotational theory of synchronous reactive systems

    OpenAIRE

    Benveniste , Albert; Le Guernic , Paul; Sorel , Yves; Sorine , Michel

    1992-01-01

    International audience; In this paper, systems which interact permanently with their environments are considered. Such systems are encountered, for instance, in real-time control or signal processing systems, C3-systems, and man-machine interfaces, to mention just a few cases. The design and implementation of such systems require a concurrent programming language which can be used to verify and synthesize the synchronization mechanisms, and to perform transformations of the concurrent source ...

  5. Reactive power compensation capability of a STATCOM based on two types of Modular Multilevel Cascade Converters for offshore wind application

    DEFF Research Database (Denmark)

    Tanaka, Takaaki; Wang, Huai; Ma, Ke

    2017-01-01

    Static Synchronous Compensators (STATCOMs) have been applied for offshore wind power plants to satisfy the grid codes under both normal operation and grid fault conditions. This paper investigates the performances of two types of Modular Multilevel Cascade Converters (MMCC) for STATCOM applications......, with the special focus on asymmetrical Low-Voltage-Ride-Through (LVRT) operation under grid faults. The design of an 80 MVar / 33 kV STATCOM is first presented. The electro-thermal stress of the power modules used in each type of MMCC is analyzed with voltage balancing control under grid faults. Finally...

  6. Design and implementation of a 2-DOF PID compensation for magnetic levitation systems.

    Science.gov (United States)

    Ghosh, Arun; Rakesh Krishnan, T; Tejaswy, Pailla; Mandal, Abhisek; Pradhan, Jatin K; Ranasingh, Subhakant

    2014-07-01

    This paper employs a 2-DOF (degree of freedom) PID controller for compensating a physical magnetic levitation system. It is shown that because of having a feedforward gain in the proposed 2-DOF PID control, the transient performance of the compensated system can be changed in a desired manner unlike the conventional 1-DOF PID control. It is also shown that for a choice of PID parameters, although the theoretical loop robustness is the same for both the compensated systems, in real-time, 2-DOF PID control may provide superior robustness if a suitable choice of the feedforward parameter is made. The results are verified through simulations and experiments. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Load compensation for single phase system using series active filter

    African Journals Online (AJOL)

    user

    Abstract. The exponentially rising application of power electronics based appliances in Domestic Consumer Voltage Distribution. System (DCVDS) has enhanced power quality problems even at the lowest voltage level in distribution system. Starting from transmission system to low voltage distribution system, quite a good ...

  8. Development of a new initial-beam-loading compensation system and its application to a free-electron-laser linac

    Directory of Open Access Journals (Sweden)

    M. Satoh

    2009-01-01

    Full Text Available We have developed an initial-beam-loading compensation system by a new compensation method, where the system modulates the phase and amplitude of a low-level rf signal simultaneously, thereby optimizing a high-power rf waveform fed to an accelerating structure to compensate the beam energy spread. This compensation system is very compact and can easily be installed in and removed from a klystron system. This system was used in a beam test performed in the 125 MeV electron linac of the Laboratory for Electron Beam Research and Application in Nihon University. Experimental results demonstrate that this system effectively corrects the beam energy spread due to the initial-beam-loading effect. The new compensation method is expected to be effective in the compensation of energy spread in high-intensity and long-pulse beams in electron linacs.

  9. An evaluation system for financial compensation in traditional Chinese medicine services.

    Science.gov (United States)

    Dou, Lei; Yin, Ai-Tian; Hao, Mo; Lu, Jun

    2015-10-01

    To describe the major factors influencing financial compensation in traditional Chinese medicine (TCM) and prioritize what TCM services should be compensated for. Two structured questionnaires-a TCM service baseline questionnaire and a service cost questionnaire-were used to collect information from TCM public hospitals on TCM services provided in certain situations and service cost accounting. The cross-sectional study examined 110 TCM services provided in four county TCM public hospitals in Shandong province. From the questionnaire data, a screening index system was established via expert consultation and brainstorming. Comprehensive evaluation of TCM services was performed using the analytic hierarchy process method. Weighted coefficients were used to measure the importance of each criterion, after which comprehensive evaluation scores for each service were ranked to indicate what services should receive priority for financial compensation. Economy value, social value, and efficacy value were the three main criteria for screening for what TCM services should be compensated for. The economy value local weight had the highest value (0.588), of which the profit sub-criterion (0.278) was the most important for TCM financial compensation. Moxibustion was tied for the highest comprehensive evaluation scores, at 0.65 while Acupuncture and Massage Therapy were tied for the second and third highest, with 0.63 and 0.58, respectively. Government and policymakers should consider offer financial compensation to Moxibustion, Acupuncture, Massage Therapy, and TCM Orthopedics as priority services. In the meanwhile, it is essential to correct the unreasonable pricing, explore compensation methods, objects and payment, and revise and improve the accounting system for the costs of TCM services. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Convergence Analysis of Wireless Remote Iterative Learning Control Systems with Dropout Compensation

    Directory of Open Access Journals (Sweden)

    Li-xun Huang

    2013-01-01

    Full Text Available The wireless remote iterative learning control (ILC system with random data dropouts is considered. The data dropout is viewed as a binary switching sequence which obeys the Bernoulli distribution. In order to eliminate the effect of data dropouts on the convergence property of output error, the signal at the same time with the lost one but in the last iteration is used to compensate the data dropout at the actuator. With the dropout compensation, the convergence property of output error is analyzed by studying the element values of system transition matrix. Finally, some simulation results are given to illustrate the validity of the proposed method.

  11. Prospective application of advanced series compensation to improve transmission system performance

    Energy Technology Data Exchange (ETDEWEB)

    Gama, C.A.; Scavassa, J.L.; Silva, W.M. da; Silva, J.M.M. da; Ponte, J.R. [ELETRONORTE, Brasilia, DF (Brazil)

    1994-12-31

    This paper describes the main aspects and results of the planning studies undertaken to evaluate the technical benefits of using Thyristor Controlled Series Compensation (TCSC), in a large 500 kV transmission system (Brazilian North-Northeast system). TCSC controllers design and simplified models for digital non-linear time domain simulations are discussed. The proposed controllers are tuned and used to support the comparative analysis between controlled and fixed series compensation. The relevant conclusions concerning this comparison are highlighted. (author) 2 refs., 14 figs., 3 tabs.

  12. Analysis and compensation of I/Q imbalance in amplify-and-forward cooperative systems

    KAUST Repository

    Qi, Jian

    2012-04-01

    In this paper, dual-hop amplify-and-forward (AF) cooperative systems in the presence of in-phase and quadrature-phase (I/Q) imbalance, which refers to the mismatch between components in I and Q branches, are investigated. First, we analyze the performance of the considered AF cooperative protocol without compensation for I/Q imbalance as the benchmark. Furthermore, a compensation algorithm for I/Q imbalance is proposed, which makes use of the received signals at the destination, from the source and relay nodes, together with their conjugations to detect the transmitted signal. The performance of the AF cooperative system under study is evaluated in terms of average symbol error probability (SEP), which is derived considering transmission over Rayleigh fading channels. Numerical results are provided and show that the proposed compensation algorithm can efficiently mitigate the effect of I/Q imbalance. © 2012 IEEE.

  13. Effection of grinding system rigidity ultra-precision grinding of aspheric mould and error compensation

    Science.gov (United States)

    Yin, S. H.; Gong, S.

    2016-10-01

    In ultra-precision oblique axis grinding process for machining micro aspherical mould, form error of aspherical surface is caused by the inconsistence elastic deformation of grinding system, which derived from differences velocity from inside to out. In this case, whole PV value can meet requirements, however, pits are produced in central after error compensation, which is unworkable. In this paper, mechanism of machining error caused by grinding system rigidity is analyzed, and experiments are carried out. Form error compensation grinding are carried out in the central local area, based on traditional error compensation method, which can effectively eliminate the pits of surface center. In this method, cemented carbide YG8 which diameter is about 6mm is ground. The results showed that the form accuracy under PV 200 nm and under PV 50 nm within the scope of 1 mm, and the surface roughness under Ra2nm.

  14. Robust terahertz self-heterodyne system using a phase noise compensation technique.

    Science.gov (United States)

    Song, Hajun; Song, Jong-In

    2015-08-10

    We propose and demonstrate a robust terahertz self-heterodyne system using a phase noise compensation technique. Conventional terahertz self-heterodyne systems suffer from degraded phase noise performance due to phase noise of the laser sources. The proposed phase noise compensation technique uses an additional photodiode and a simple electric circuit to produce phase noise identical to that observed in the terahertz signal produced by the self-heterodyne system. The phase noise is subsequently subtracted from the terahertz signal produced by the self-heterodyne system using a lock-in amplifier. While the terahertz self-heterodyne system using a phase noise compensation technique offers improved phase noise performance, it also provides a reduced phase drift against ambient temperature variations. The terahertz self-heterodyne system using a phase noise compensation technique shows a phase noise of 0.67 degree in terms of a standard deviation value even without using overall delay balance control. It also shows a phase drift of as small as approximately 10 degrees in an open-to-air measurement condition without any strict temperature control.

  15. Healing or harming? Healthcare provider interactions with injured workers and insurers in workers' compensation systems.

    Science.gov (United States)

    Kilgour, Elizabeth; Kosny, Agnieszka; McKenzie, Donna; Collie, Alex

    2015-03-01

    Healthcare providers (HCPs) are influential in the injured worker's recovery process and fulfil many roles in the delivery of health services. Interactions between HCPs and insurers can also affect injured workers' engagement in rehabilitation and subsequently their recovery and return to work. Consideration of the injured workers' perceptions and experiences as consumers of medical and compensation services can provide vital information about the quality, efficacy and impact of such systems. The aim of this systematic review was to identify and synthesize published qualitative research that focused on the interactions between injured workers, HCPs and insurers in workers' compensation systems in order to identify processes or interactions which impact injured worker recovery. A search of six electronic databases for literature published between 1985 and 2012 revealed 1,006 articles. Screening for relevance identified 27 studies which were assessed for quality against set criteria. A final 13 articles of medium and high quality were retained for data extraction. Findings were synthesized using a meta-ethnographic approach. Injured workers reported that HCPs could play both healing and harming roles in their recovery. Supportive patient-centred interaction with HCPs is important for injured workers. Difficult interactions between HCPs and insurers were highlighted in themes of adversarial relations and organisational pressures. Insurer and compensation system processes exerted an influence on the therapeutic relationship. Recommendations to improve relationships included streamlining administrative demands and increasing education and communication between the parties. Injured workers with long term complex injuries experience difficulties with healthcare in the workers' compensation context. Changes in insurer administrative demands and compensation processes could increase HCP participation and job satisfaction. This in turn may improve injured worker recovery

  16. System Error Compensation Methodology Based on a Neural Network for a Micromachined Inertial Measurement Unit

    Science.gov (United States)

    Liu, Shi Qiang; Zhu, Rong

    2016-01-01

    Errors compensation of micromachined-inertial-measurement-units (MIMU) is essential in practical applications. This paper presents a new compensation method using a neural-network-based identification for MIMU, which capably solves the universal problems of cross-coupling, misalignment, eccentricity, and other deterministic errors existing in a three-dimensional integrated system. Using a neural network to model a complex multivariate and nonlinear coupling system, the errors could be readily compensated through a comprehensive calibration. In this paper, we also present a thermal-gas MIMU based on thermal expansion, which measures three-axis angular rates and three-axis accelerations using only three thermal-gas inertial sensors, each of which capably measures one-axis angular rate and one-axis acceleration simultaneously in one chip. The developed MIMU (100 × 100 × 100 mm3) possesses the advantages of simple structure, high shock resistance, and large measuring ranges (three-axes angular rates of ±4000°/s and three-axes accelerations of ±10 g) compared with conventional MIMU, due to using gas medium instead of mechanical proof mass as the key moving and sensing elements. However, the gas MIMU suffers from cross-coupling effects, which corrupt the system accuracy. The proposed compensation method is, therefore, applied to compensate the system errors of the MIMU. Experiments validate the effectiveness of the compensation, and the measurement errors of three-axis angular rates and three-axis accelerations are reduced to less than 1% and 3% of uncompensated errors in the rotation range of ±600°/s and the acceleration range of ±1 g, respectively. PMID:26840314

  17. The feasibility of the auto tuning respiratory compensation system with ultrasonic image tracking technique.

    Science.gov (United States)

    Chuang, Ho-Chiao; Hsu, Hsiao-Yu; Nieh, Shu-Kan; Tien, Der-Chi

    2015-01-01

    The purpose of this study is to assess the feasibility of using the analytical technique of ultrasound images in combination with an auto tumor localization system. During respiration, the activity of breathing in and out causes organs displacement at the lower lobe of the lung, and the maximum displacement range happens in the Superior-Inferior (SI) direction. Therefore, in this study all the tumor positioning is in SI direction under respiratory compensation, in which the compensations are carried out to the organs at the lower lobe and adjacent to the lower lobe of lung.In this research, due to the processes of ultrasound imaging generation, image analysis and signal transmission, when the captured respiratory signals are sent to auto tumor localization system, there was a signal time delay. The total delay time of the entire signal transmission process was 0.254 ± 0.023 seconds (with the lowest standard deviation) after implementing a series of analyses. To compensate for this signal delay time (0.254 ± 0.023 sec), a phase lead compensator (PLC) was designed and built into the auto tumor localization system. By analyzing the impact of the delay time and the respiratory waveforms under different frequencies on the phase lead compensator, an overall system delay time can be configured. Results showed as the respiratory frequency increased, variable value ``a'' and the subsequent gain ``k'' in the controller becomes larger. Moreover, value ``a'' and ``k'' increased as the system delay time increased when the respiratory frequency was fixed. The relationship of value ``a'' and ``k'' to the respiratory frequency can be obtained by using the curve fitting method to compensate for the respiratory motion for tumor localization. Through the comparison of the uncompensated signal and the compensated signal performed by the auto tumor localization system on the simulated respiratory signal, the feasibility of using ultrasound image analysis technology combined with the

  18. Load compensation for single phase system using series active filter ...

    African Journals Online (AJOL)

    In this paper a new control strategy for series active filter has been proposed for improvement of power quality problems in single phase system. Since the non linear loads in the system comprises of both voltage source harmonic and current source harmonic loads and the dominancy of each type of load varies from time to ...

  19. Low Value Capacitance Measurement System with Adjustable Lead Capacitance Compensation

    OpenAIRE

    Gautam Sarkar; Anjan Rakshit; Amitava Chatterjee; Kesab Bhattacharya

    2013-01-01

    The present paper describes the development of a low cost, highly accurate low capacitance measurement system that can be used over a range of 0 – 400 pF with a resolution of 1 pF. The range of capacitance may be easily altered by a simple resistance or capacitance variation of the measurement circuit. This capacitance measurement system uses quad two-input NAND Schmitt trigger circuit CD4093B with hysteresis for the measurement and this system is integrated with PIC 18F2550 microcontroller f...

  20. Half-metallic compensated ferrimagnetism with a tunable compensation point over a wide temperature range in the Mn-Fe-V-Al Heusler system

    Directory of Open Access Journals (Sweden)

    Rolf Stinshoff

    2017-10-01

    Full Text Available The cubic Heusler compound Mn1.5FeV0.5Al with the L21 Heusler structure is the first fully compensated half-metallic ferrimagnet with 24 valence electrons. The ferrimagnetic state can be tuned by changing the composition such that the compensation point appears at finite temperatures ranging from 0 K up to 226 K, while retaining half-metallicity in the system. In this paper, the structural, magnetic and transport properties of the Mn-Fe-V-Al system are discussed. Magnetic reversal and a change of sign of the anomalous Hall effect were observed at the compensation point, which gives rise to a sublattice spin-crossing. These materials present new possibilities for potential spintronic devices because of their advantageous properties such as imperceptibility to external fields, lower power consumption and ultrafast switching in the THz region.

  1. Design and synthesis of reactive separation systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, M.F.

    1992-12-31

    During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

  2. Power system compensation using a power electronics integrated transformer

    OpenAIRE

    Atef Abbas Elsaharty, Mohamed; Candela García, José Ignacio; Rodríguez Cortés, Pedro

    2017-01-01

    This paper presents a new transformer, i.e., the Custom Power Active Transformer (CPAT) - which integrates shunt and series equivalent circuits within the transformer's magnetic structure. Thus, it provides power system services using a single transformer. The CPAT equipped with a power converter can be utilized in distribution systems to control grid-current and load-voltage waveforms while operating as a step-up or step-down transformer between the grid and load. Moreover, it can provide ot...

  3. Reactive Power Management in Electric Power Systems

    African Journals Online (AJOL)

    The quality of electric power at a supply point can be quantified in terms of how stab)e are the voltage and frequency and how close is the power factor to unity. The continuity of supply and in three-phase systems the degree to which the phase currents and voltages are balanced constitute additional quality parameters.

  4. Online Sensor Drift Compensation for E-Nose Systems Using Domain Adaptation and Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Zhiyuan Ma

    2018-03-01

    Full Text Available Sensor drift is a common issue in E-Nose systems and various drift compensation methods have received fruitful results in recent years. Although the accuracy for recognizing diverse gases under drift conditions has been largely enhanced, few of these methods considered online processing scenarios. In this paper, we focus on building online drift compensation model by transforming two domain adaptation based methods into their online learning versions, which allow the recognition models to adapt to the changes of sensor responses in a time-efficient manner without losing the high accuracy. Experimental results using three different settings confirm that the proposed methods save large processing time when compared with their offline versions, and outperform other drift compensation methods in recognition accuracy.

  5. How do workers with a notified mental disorder experience the Danish Workers’ Compensation System?

    DEFF Research Database (Denmark)

    Ladegaard, Yun Katrine

    2014-01-01

    ), but research exploring workers' experiences of the WCS and what factors can lead to and protect against WD are lacking. This study aims at bridging this gap. Methods Semi-structured interviews were conducted with 10 workers notified with a mental disorder. The interview guide was developed based...... to fill out, and questions addressing the psychosocial work environment were missing. Communication from the Board of industrial Injuries (BOII) was lacking, and procedure and timelines unclear. Workers' goal was not to achieve eeconomical compensation, but that their disorder was recognised as caused......Background An increasing number of employees is notified with a mental disorder in the Danish Workers’ Compensation System (WCS). However, only few are recognized and even less are granted a compensation. Research shows that notification in WCS increases the risk of work disability (WD...

  6. Online Sensor Drift Compensation for E-Nose Systems Using Domain Adaptation and Extreme Learning Machine

    Science.gov (United States)

    Luo, Guangchun; Qin, Ke; Wang, Nan; Niu, Weina

    2018-01-01

    Sensor drift is a common issue in E-Nose systems and various drift compensation methods have received fruitful results in recent years. Although the accuracy for recognizing diverse gases under drift conditions has been largely enhanced, few of these methods considered online processing scenarios. In this paper, we focus on building online drift compensation model by transforming two domain adaptation based methods into their online learning versions, which allow the recognition models to adapt to the changes of sensor responses in a time-efficient manner without losing the high accuracy. Experimental results using three different settings confirm that the proposed methods save large processing time when compared with their offline versions, and outperform other drift compensation methods in recognition accuracy. PMID:29494543

  7. Hybrid VAR compensator with improved efficiency

    Directory of Open Access Journals (Sweden)

    V. V. Burlaka

    2015-03-01

    Full Text Available In modern electrical networks thyristor-switched capacitors (TSC are most used devices for VAR compensation. These devices don’t contain rotating parts and mechanical contacts, provide a stepwise control of reactive power and no generation of harmonics to the network. However, with the help of TSC it’s not possible to ensure smooth control of reactive power and capacitor banks (CB are exposed to the negative impact of higher harmonic components of the network voltage. Hybrid VAR compensator don’t have such drawbacks. It consists of active filter (AF and capacitor bank with discrete regulation. The main drawback of such systems is the necessity of accessing all six terminals of CB, while most of them are manufactured with three terminals, internally delta-connected. In the article, the topology and control system of hybrid VAR compensator free from beforementioned drawback, is proposed. The control system provides operating modes of overcompensation or undercompensation reactive power. VAR distribution regulator performs redistribution of reactive power between active filter and capacitor banks with the condition to minimize active filter’s power. Scheme of the hybrid VAR compensator, which includes a three-phase three-terminal delta-connected capacitor banks, is shown. Proposed approach allows to provide smooth control of reactive power, isolate the capacitor bank from harmonic currents and use a more effective low-voltage power components

  8. Multipurpose Compensation Scheme for Voltage Sag/Swell and Selective Harmonics Elimination in Distribution Systems

    Directory of Open Access Journals (Sweden)

    Mustafa Inci

    2018-01-01

    Full Text Available Voltage harmonics, sag, and swell are the most harmful disturbances in distribution systems. This paper introduces a novel effective controller method for simultaneous compensation of both voltage sag/swell and voltage harmonics by using multifunctional dynamic voltage restorer. In proposed controller method called FFT with integrated ISRF, ISRF detects the magnitudes of voltage sag/swell quickly and precisely, and FFT extracts the selective components of voltage harmonics very effectively. The proposed method integrates the superior properties of ISRF and FFT methods. FFT integrated ISRF is applied for the first time to provide the compensation of both sag/swell and selective harmonics together. The proposed system has ability to compensate symmetrical/asymmetrical sag/swell and symmetrical/asymmetrical selective harmonics which are 5th, 7th, 11th and 13th. The controlled system is modelled in PSCAD/EMDTC and compared with conventional methods. The performance results verify that the proposed method compensates voltage disturbances effectively in the system.

  9. Automatic Visualization of Software Requirements: Reactive Systems

    International Nuclear Information System (INIS)

    Castello, R.; Mili, R.; Tollis, I.G.; Winter, V.

    1999-01-01

    In this paper we present an approach that facilitates the validation of high consequence system requirements. This approach consists of automatically generating a graphical representation from an informal document. Our choice of a graphical notation is statecharts. We proceed in two steps: we first extract a hierarchical decomposition tree from a textual description, then we draw a graph that models the statechart in a hierarchical fashion. The resulting drawing is an effective requirements assessment tool that allows the end user to easily pinpoint inconsistencies and incompleteness

  10. Dual PD Control Regulation with Nonlinear Compensation for a Ball and Plate System

    Directory of Open Access Journals (Sweden)

    Sergio Galvan-Colmenares

    2014-01-01

    Full Text Available The normal proportional derivative (PD control is modified to a new dual form for the regulation of a ball and plate system. First, to analyze this controller, a novel complete nonlinear model of the ball and plate system is obtained. Second, an asymptotic stable dual PD control with a nonlinear compensation is developed. Finally, the experimental results of ball and plate system are provided to verify the effectiveness of the proposed methodology.

  11. Motor System Plasticity and Compensation in Multiple Sclerosis

    OpenAIRE

    Daniel Zeller

    2015-01-01

    Multiple sclerosis (MS) affects the central nervous system (CNS) by inflammatory lesions, direct axonal injury, and by a rather diffuse and widespread neurodegeneration. For a long time, research has mainly focused on these destructive aspects of MS, while the compensatory effects of cellular repair and neural plasticity have received little consideration. However, as current effective immunomodulatory therapies may limit rather than preclude demyelination and axonal damage, additional therap...

  12. Satisfaction, Motivation, and Retention in Academic Faculty Incentive Compensation Systems: A CERA Survey.

    Science.gov (United States)

    Willis, Deanna; Williams, Jane; Gebke, Kevin; Bergus, George

    2018-02-01

    The use of incentive compensation in academic family medicine has been a topic of interest for many years, yet little is known about the impact of these systems on individual faculty members. Better understanding is needed about the relationship of incentive compensation systems (ICSs) to ICS satisfaction, motivation, and retention among academic family medicine faculty. The Council of Academic Family Medicine (CAFM) Educational Research Alliance (CERA) conducted a nationwide survey of its members in 2013. This study reports the results of the incentive compensation question subset of the larger omnibus survey. The overall response rate was 53%. The majority (70% [360/511]) of academic faculty reported that they are eligible for some type of incentive compensation. The faculty reported moderate satisfaction, with only 38% being satisfied or highly satisfied with their ICS. Overall mean motivation and intent to remain in their current position were similar. The percentage of total income available as an incentive explained less than 10% of the variance of those outcomes. Faculty perceptions of appropriateness of the measures, understanding of the measurement and reward systems, and perception of due process are all related to satisfaction with the ICS, motivation, and retention. ICSs are common in academic family medicine, yet most faculty do not find them to motivate their choice of activities or promote staying in their current position. Design and implementation are both important in promoting faculty satisfaction with the ICS, motivation, and retention.

  13. Two-dimensional simulation of reactive diffusion in binary systems

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jiří; Stopka, J.; Fischer, F. D.

    2014-01-01

    Roč. 95, DEC (2014), s. 309-315 ISSN 0927-0256 R&D Projects: GA ČR(CZ) GA14-24252S Institutional support: RVO:68081723 Keywords : Phase transformation * Diffusion-controlled interface migration * Reactive diffusion * Multiphase system * Intermetallic compounds Subject RIV: BJ - Thermodynamics Impact factor: 2.131, year: 2014

  14. Abstract interpretation of reactive systems : preservation of CTL*

    NARCIS (Netherlands)

    Dams, D.; Grumberg, O.; Gerth, R.

    The advent of ever more complex reactive systems in increasingly critical areas calls for the development of automated verification techniques. Model checking is one such technique, which has proven quite successful. However, the state explosion problem remains the stumbling block in many

  15. Hematocrit Compensation in Electrochemical Blood Glucose Monitoring Systems

    Science.gov (United States)

    Teodorczyk, Maria; Cardosi, Marco; Setford, Steven

    2012-01-01

    Background Hematocrit (Hct) is a common interferent in test strips used by diabetes patients to self-monitor blood glucose (BG), resulting in measurement bias. Described is an electrochemical BG monitoring system (OneTouch® Verio™) that uses a cofacial sensor design, soluble enzyme chemistry, and multiphasic waveform to effectively correct for patient Hct, delivering an accurate reading for whole BG. Methods The test strip comprises thin-film gold and palladium electrodes arranged cofacially and spatially separated with a thin spacer. Soluble glucose-sensing reagents are located on the lower palladium electrode and are hydrated on sample application. Blood glucose is oxidized by flavoprotein glucose dehydrogenase, with electron transfer via (reduced) potassium ferrocyanide mediator at the palladium electrode. Hematocrit levels are estimated by measuring oxidation of mediator diffusion to the upper gold electrode during the first portion of the assay. The Hct-corrected glucose levels are determined by an on-meter algorithm. Results In performance testing of blood samples at five glucose levels (30–560 mg/dl) and five Hct levels (19–61%), using 12 test meters and 3 test strip lots, 100% of results (N = 2700) met International Organization for Standardization accuracy criteria (within ± 15 mg/dl and ± 20% of reference results at glucose levels of <75 and ≥75 mg/dl, respectively). Furthermore, 99.9% (2698 of 2700) of results were within ±12 mg/dl and ± 15% of reference values at glucose levels <80 and ≥80 mg/dl, respectively. Conclusions The technology used in this system provides accurate BG measurements that are insensitive to Hct levels across the range 20–60%. PMID:22768896

  16. Assesment and Analyze Hybride Control System in Distribution Static Synchronous Compensator Based Current Source Converter

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Ali Zanjani

    2011-10-01

    Full Text Available With the rapid technology advancement in control processes, electric utilities are experiencing more demanding requirements on the power quality from the large industrial power consumers. For achieved this purpose use of FACTS devices. One of kind compensator is D-Statcom, using in distribution system for conquest of power quality problem. This paper presents system modeling and control design techniques of distribution static synchronous compensator. For reach an optimal design, using a hybride state-feedback and d-q control systems. Using direct sampling on network parameter, than conventional control system, as well as fast dynamic responses are achieved. The derived simulations are tried to verify the result of this paper.

  17. Impact of seasonal forcing on reactive ecological systems.

    Science.gov (United States)

    Vesipa, Riccardo; Ridolfi, Luca

    2017-04-21

    Our focus is on the short-term dynamics of reactive ecological systems which are stable in the long term. In these systems, perturbations can exhibit significant transient amplifications before asymptotically decaying. This peculiar behavior has attracted increasing attention. However, reactive systems have so far been investigated assuming that external environmental characteristics remain constant, although environmental conditions (e.g., temperature, moisture, water availability, etc.) can undergo substantial changes due to seasonal cycles. In order to fill this gap, we propose applying the adjoint non-modal analysis to study the impact of seasonal variations of environmental conditions on reactive systems. This tool allows the transient dynamics of a perturbation affecting non-autonomous ecological systems to be described. To show the potential of this approach, a seasonally forced prey-predator model with a Holling II type functional response is studied as an exemplifying case. We demonstrate that seasonalities can greatly affect the transient dynamics of the system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Nonlinear compensation techniques for magnetic suspension systems. Ph.D. Thesis - MIT

    Science.gov (United States)

    Trumper, David L.

    1991-01-01

    In aerospace applications, magnetic suspension systems may be required to operate over large variations in air-gap. Thus the nonlinearities inherent in most types of suspensions have a significant effect. Specifically, large variations in operating point may make it difficult to design a linear controller which gives satisfactory stability and performance over a large range of operating points. One way to address this problem is through the use of nonlinear compensation techniques such as feedback linearization. Nonlinear compensators have received limited attention in the magnetic suspension literature. In recent years, progress has been made in the theory of nonlinear control systems, and in the sub-area of feedback linearization. The idea is demonstrated of feedback linearization using a second order suspension system. In the context of the second order suspension, sampling rate issues in the implementation of feedback linearization are examined through simulation.

  19. Former migrant mineworkers with respiratory disease: the South African compensation system, and implications for neighbouring countries.

    Science.gov (United States)

    Steen, T W; Mabongo, N; Moeti, T; Monare, B; Trapido, A S

    2000-01-01

    In the region of Southern Africa, substantial numbers of people, primarily males, have been employed in the South African mining industry. Migrant workers from neighbouring countries have constituted a large part of the work force. Until recently, there has been little or no attention directed toward the state of health of these individuals, despite the fact that their work involves a high health risk, especially in regard to mine-related lung diseases. In addition, the South African workers' compensation programme has seldom been utilised by the migrant worker who is a victim of occupational disease. However, recent experiences from Botswana show that compensation claims can be successfully made from the neighbouring countries where the migrant workers originate. Efforts are being made to address the problem systematically, and the government of Botswana is actively involved. The major occupational lung disorders are described briefly, and differential diagnostic problems with pulmonary TB are discussed. Furthermore, a survey of the compensation system in South Africa is presented, and practical steps for medical examinations involving compensation claims are described.

  20. A new method for distortion magnetic field compensation of a geomagnetic vector measurement system

    International Nuclear Information System (INIS)

    Liu, Zhongyan; Pan, Mengchun; Tang, Ying; Zhang, Qi; Geng, Yunling; Wan, Chengbiao; Chen, Dixiang; Tian, Wugang

    2016-01-01

    The geomagnetic vector measurement system mainly consists of three-axis magnetometer and an INS (inertial navigation system), which have many ferromagnetic parts on them. The magnetometer is always distorted by ferromagnetic parts and other electric equipments such as INS and power circuit module within the system, which can lead to geomagnetic vector measurement error of thousands of nT. Thus, the geomagnetic vector measurement system has to be compensated in order to guarantee the measurement accuracy. In this paper, a new distortion magnetic field compensation method is proposed, in which a permanent magnet with different relative positions is used to change the ambient magnetic field to construct equations of the error model parameters, and the parameters can be accurately estimated by solving linear equations. In order to verify effectiveness of the proposed method, the experiment is conducted, and the results demonstrate that, after compensation, the components errors of measured geomagnetic field are reduced significantly. It demonstrates that the proposed method can effectively improve the accuracy of the geomagnetic vector measurement system. (paper)

  1. Distributed Reactive Power Control based Conservation Voltage Reduction in Active Distribution Systems

    OpenAIRE

    EMIROGLU, S.; UYAROGLU, Y.; OZDEMIR, G.

    2017-01-01

    This paper proposes a distributed reactive power control based approach to deploy Volt/VAr optimization (VVO) / Conservation Voltage Reduction (CVR) algorithm in a distribution network with distributed generations (DG) units and distribution static synchronous compensators (D-STATCOM). A three-phase VVO/CVR problem is formulated and the reactive power references of D-STATCOMs and DGs are determined in a distributed way by decomposing the VVO/CVR problem into voltage and reacti...

  2. Voltage Control in Distribution Systems Considered Reactive Power Output Sharing

    Science.gov (United States)

    Oshiro, Masato; Senjyu, Tomonobu; Yona, Atsushi; Urasaki, Naomitsu; Funabashi, Toshihisa

    In recent years, distributed generation (DG) and renewable energy source (RES) are attracting special attention to distribution systems. Renewable energy such as photovoltaic (PV) system and wind turbine generator are used as a source of clean energy. However, the large amount of distributed generation causes voltage deviation beyond a statutory range in distribution systems. This paper proposes a methodology for voltage control by using inverters interfaced with DG and tap changing transformers. In the proposed method a one-day schedule of voltage references for the control devices are determined by an optimization technique based on predicted values of load demand and PV power generation. Furthermore, decided reactive power output according to the locally measurable voltage based on droop characteristic. Slope and base value on droop characteristic are selected by fuzzy control. The proposed method accomplishes improvement against voltage distribution considered the reactive power output sharing and reduction of distribution loss. The effectiveness of the proposed method is verified by using MATLAB®.

  3. [Functional analysis of the smart vent compensation system and the fresh gas decoupling system].

    Science.gov (United States)

    Matsumoto, Kappei

    2008-07-01

    In MIPPV mode, an anesthetic machine supplies a fixed amount of tidal volume (TV) corresponding to changes of fresh gas flow (FGF) in a certain period of time. In this research, we examined discrepancy of delivered TV and preset TV, after a change of FGF in both fresh gas decoupling system (FGDS) and smart vent compensation system(SVCS). FGF value was changed from 0.1 l x min(-1) to 12 l min(-1), and after 10 times of ventilation, we measured TV and peak pressure of inspiratory circuit pressure(PIP). Following a gradual FGF increase, PIP dramatically increased in FGDS. TV and PIP; however, remained unchanged in SVCS. FDGS has a valve for closing FGF in the inspiratory phase and it makes the gas circuit over volume, but SVCS changes the volume of gas delivery to the ventilator by CPU according to FGF changes. Therefore it is assumed that the safety system of SVCS is superior to FDGS in high and low FGF.

  4. Employee Compensation.

    Science.gov (United States)

    Osif, Bonnie A.; Harwood, Richard L.

    1995-01-01

    Presents an overview of selected literature about employee compensation. Highlights include the foundations of reward and recognition systems, incentive plans, problems with merit pay, a historical perspective on performance pay, evaluation criteria and processes, self-rating, job motivation and satisfaction, employee attitudes, collective…

  5. [Risk Management of HBV Reactivation: Construction of Check System].

    Science.gov (United States)

    Tanaka, Yasuhito

    2015-09-01

    In recent years, reactivation of HBV in patients receiving cancer chemotherapy or immunosuppressive therapy has been a problem. Generally, HBV-DNA levels are elevated prior to HBsAg concentration, and then hepatic dysfunction is observed in the process of hepatitis by HBV reactivation. Therefore, the monitoring of HBV-DNA is useful for the prediction of hepatic dysfunction, and nucleoside/nucleoside analogue (NA) administration is able to prevent this HBV reactivation. According to these facts, "Guidelines for the Prevention of HBV Reactivation in Patients Receiving Immunosuppressive Therapy or Chemotherapy", 2009 (revised as "JSH Guidelines for the Management of Hepatitis B Virus Infection", 2013) is established, and the diagnostic algorithm of HBsAg, anti-HBc, anti-HBs, and HBV-DNA has relevant descriptions. Combination therapy with rituximab and steroid for malignant lymphoma has a high risk of leading to fulminant hepatitis and, consequently, the guidelines are widely followed in such cases. We introduced the improvement of electronic medical recording and ordering systems in collaboration with hepatologists, and such a system has been widely used. Although the monitoring of HBV-DNA levels is required every 1-3 months, the guidelines are not followed strictly in cases such as rheumatoid disease and solid tumors only with chemotherapy or steroid treatment. Since a DNA assay is complicated and expensive, cost-effective, time-saving, and highly sensitive/specific measurements are required as well. Therefore, Lumipulse HBsAg-HQ (CLIA method) with high sensitivity is expected to be used for the monitoring of HBV reactivation.

  6. Compensating for Channel Fading in DS-CDMA Communication Systems Employing ICA Neural Network Detectors

    Directory of Open Access Journals (Sweden)

    David Overbye

    2005-06-01

    Full Text Available In this paper we examine the impact of channel fading on the bit error rate of a DS-CDMA communication system. The system employs detectors that incorporate neural networks effecting methods of independent component analysis (ICA, subspace estimation of channel noise, and Hopfield type neural networks. The Rayleigh fading channel model is used. When employed in a Rayleigh fading environment, the ICA neural network detectors that give superior performance in a flat fading channel did not retain this superior performance. We then present a new method of compensating for channel fading based on the incorporation of priors in the ICA neural network learning algorithms. When the ICA neural network detectors were compensated using the incorporation of priors, they give significantly better performance than the traditional detectors and the uncompensated ICA detectors. Keywords: CDMA, Multi-user Detection, Rayleigh Fading, Multipath Detection, Independent Component Analysis, Prior Probability Hebbian Learning, Natural Gradient

  7. Combination of Compensations and Multi-Parameter Coil for Efficiency Optimization of Inductive Power Transfer System

    Directory of Open Access Journals (Sweden)

    Guozhen Hu

    2017-12-01

    Full Text Available A loosely coupled inductive power transfer (IPT system for industrial track applications has been researched in this paper. The IPT converter using primary Inductor-Capacitor-Inductor (LCL network and secondary parallel-compensations is analyzed combined coil design for optimal operating efficiency. Accurate mathematical analytical model and expressions of self-inductance and mutual inductance are proposed to achieve coil parameters. Furthermore, the optimization process is performed combined with the proposed resonant compensations and coil parameters. The results are evaluated and discussed using finite element analysis (FEA. Finally, an experimental prototype is constructed to verify the proposed approach and the experimental results show that the optimization can be better applied to industrial track distributed IPT system.

  8. Formal Requirements Modeling for Reactive Systems with Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon

    . This is important because it represents the identi cation of what is being designed (the reactive system), and what is given and being made assumptions about (the environment). The representation of the environment is further partitioned to distinguish human actors from non-human actors. This allows the modeler...... to addressing the problem of validating formal requirements models through interactive graphical animations is presented. Executable Use Cases (EUCs) provide a framework for integrating three tiers of descriptions of specifications and environment assumptions: the lower tier is an informal description...... to distinguish the modeling artifacts describing the environment from those describing the specifications for a reactive system. The formalization allows for clear identi cation of interfaces between interacting domains, where the interaction takes place through an abstraction of possibly parameterized states...

  9. Compensation for positioning error of industrial robot for flexible vision measuring system

    Science.gov (United States)

    Guo, Lei; Liang, Yajun; Song, Jincheng; Sun, Zengyu; Zhu, Jigui

    2013-01-01

    Positioning error of robot is a main factor of accuracy of flexible coordinate measuring system which consists of universal industrial robot and visual sensor. Present compensation methods for positioning error based on kinematic model of robot have a significant limitation that it isn't effective in the whole measuring space. A new compensation method for positioning error of robot based on vision measuring technique is presented. One approach is setting global control points in measured field and attaching an orientation camera to vision sensor. Then global control points are measured by orientation camera to calculate the transformation relation from the current position of sensor system to global coordinate system and positioning error of robot is compensated. Another approach is setting control points on vision sensor and two large field cameras behind the sensor. Then the three dimensional coordinates of control points are measured and the pose and position of sensor is calculated real-timely. Experiment result shows the RMS of spatial positioning is 3.422mm by single camera and 0.031mm by dual cameras. Conclusion is arithmetic of single camera method needs to be improved for higher accuracy and accuracy of dual cameras method is applicable.

  10. A Nonlinear Multiparameters Temperature Error Modeling and Compensation of POS Applied in Airborne Remote Sensing System

    Directory of Open Access Journals (Sweden)

    Jianli Li

    2014-01-01

    Full Text Available The position and orientation system (POS is a key equipment for airborne remote sensing systems, which provides high-precision position, velocity, and attitude information for various imaging payloads. Temperature error is the main source that affects the precision of POS. Traditional temperature error model is single temperature parameter linear function, which is not sufficient for the higher accuracy requirement of POS. The traditional compensation method based on neural network faces great problem in the repeatability error under different temperature conditions. In order to improve the precision and generalization ability of the temperature error compensation for POS, a nonlinear multiparameters temperature error modeling and compensation method based on Bayesian regularization neural network was proposed. The temperature error of POS was analyzed and a nonlinear multiparameters model was established. Bayesian regularization method was used as the evaluation criterion, which further optimized the coefficients of the temperature error. The experimental results show that the proposed method can improve temperature environmental adaptability and precision. The developed POS had been successfully applied in airborne TSMFTIS remote sensing system for the first time, which improved the accuracy of the reconstructed spectrum by 47.99%.

  11. Performance enhancement of a Lorentz force velocimeter using a buoyancy-compensated magnet system

    International Nuclear Information System (INIS)

    Ebert, R; Leineweber, J; Resagk, C

    2015-01-01

    Lorentz force velocimetry (LFV) is a highly feasible method for measuring flow rate in a pipe or a duct. This method has been established for liquid metal flows but also for electrolytes such as saltwater. A decrease in electrical conductivity of the medium causes a decrease of the Lorentz force which needs to be resolved, affecting the accuracy of the measurement. We use an electrical force compensation (EFC) balance for the determination of the tiny force signals in a test channel filled with electrolyte solution. It is used in a 90°-rotated orientation with a magnet system hanging vertically on its load bar. The thin coupling elements of its parallel guiding system limit the mass of the magnets to 1 kg. To overcome this restriction, which limits the magnetic flux density and hence the Lorentz forces, a weight force compensation mechanism is developed. Therefore, different methods such as air bearing are conceivable, but for the elimination of additional horizontal force components which would disturb the force signal, only compensation by lift force provided by buoyancy is reasonable. We present a swimming body setup that will allow larger magnet systems than before, because a large amount of the weight force will be compensated by this lift force. Thus the implementation of this concept has to be made with respect to hydrodynamical and mechanical stability. This is necessary to avoid overturning of the swimming body setup and to prevent inelastic deformation. Additionally, the issue will be presented and discussed whether thermal convection around the lifting body diminishes the signal-to-noise ratio (SNR) significantly or not. (paper)

  12. Modeling and motion compensation of a bidirectional tendon-sheath actuated system for robotic endoscopic surgery.

    Science.gov (United States)

    Sun, Zhenglong; Wang, Zheng; Phee, Soo Jay

    2015-04-01

    Recent study shows that tendon-sheath system (TSS) has great potential in the development of surgical robots for endoscopic surgery. It is able to deliver adequate power in a light-weight and compact package. And the flexibility and compliance of the tendon-sheath system make it capable of adapting to the long and winding path in the flexible endoscope. However, the main difficulties in precise control of such system fall on the nonlinearities of the system behavior and absence of necessary sensory feedback at the surgical end-effectors. Since accurate position control of the tool is a prerequisite for efficacy, safety and intuitive user-experience in robotic surgery, in this paper we propose a system modeling approach for motion compensation. Based on a bidirectional actuated system using two separate tendon-sheaths, motion transmission is firstly characterized. Two types of positional errors due to system backlash and environment loading are defined and modeled. Then a model-based feedforward compensation method is proposed for open-loop control, giving the system abilities to adjust according to changes in the transmission route configuration without any information feedback from the distal end. A dedicated experimental platform emulating a bidirectional TSS robotic system for endoscopic surgery is built for testing. Proposed positional errors are identified and verified. The performance of the proposed motion compensation is evaluated by trajectory tracking under different environment loading conditions. And the results demonstrate that accurate position control can be achieved even if the transmission route configuration is updated. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Shaft torsional oscillation interactions between turbo-generators in parallel in series compensated transmission systems

    Energy Technology Data Exchange (ETDEWEB)

    Mello, F.P. de

    1994-12-31

    Several investigators have raised the possibility of interaction between shaft systems of parallel units, particularly among identical units. The question addressed in this paper is the significance of this interaction between shaft systems of units coupled through the electrical system. A time domain model of two parallels units connected to an infinite bus trough a series compensated transmission is used to evaluate the phenomena. The same model is used to extract pertinent frequency response functions by Fourier processing of pulse response tests from which a frequency response analysis is performed to lend additional insight into the phenomena. (author) 8 refs., 13 figs., 3 tabs.

  14. Load Torque Compensator for Model Predictive Direct Current Control in High Power PMSM Drive Systems

    DEFF Research Database (Denmark)

    Preindl, Matthias; Schaltz, Erik

    2010-01-01

    the use of a current controller which takes into account the discrete states of the inverter, e.g. DTC or a more modern approach: Model Predictive Direct Current Control (MPDCC). Moreover overshoots and oscillations in the speed are not desired in many applications, since they lead to mechanical stress......In drive systems the most used control structure is the cascade control with an inner torque, i.e. current and an outer speed control loop. The fairly small converter switching frequency in high power applications, e.g. wind turbines lead to modest speed control performance. An improvement bring...... behaviour. It compensates the load torque influence on the speed control setting a feed forward torque value, i.e. current reference value. The benefits are twice. The speed controller reaches immediately the speed reference value avoiding offsets which must be compensated by the weak integrator. Moreover...

  15. Reactivity control system of the high temperature engineering test reactor

    International Nuclear Information System (INIS)

    Tachibana, Yukio; Sawahata, Hiroaki; Iyoku, Tatsuo; Nakazawa, Toshio

    2004-01-01

    The reactivity control system of the high temperature engineering test reactor (HTTR) consists of a control rod system and a reserve shutdown system. During normal operation, reactivity is controlled by the control rod system, which consists of 32 control rods (16 pairs) and 16 control rod drive mechanisms except for the case when the center control rods are removed to perform an irradiation test. In an unlikely event that the control rods fail to be inserted, reserve shutdown system is provided to insert pellets of neutron-absorbing material into the core. Alloy 800H is chosen for the metallic parts of the control rods. Because the maximum temperature of the control rods reaches about 900 deg. C at reactor scrams, structural design guideline and design material data on Alloy 800H are needed for the high temperature design. The design guideline for the HTTR control rod is based on ASME Code Case N-47-21. Design material data is also determined and shown in this paper. Observing the guideline, temperature and stress analysis were conducted; it can be confirmed that the target life of the control rods of 5 years can be achieved. Various tests conducted for the control rod system and the reserve shutdown system are also described

  16. Reactive Power Capability of the Wind Turbine with Doubly Fed Induction Generator

    DEFF Research Database (Denmark)

    Tian, Jie; Su, Chi; Chen, Zhe

    2013-01-01

    and reactive power compensation at the point of common coupling (PCC). Besides the shunt flexible alternating current transmission system (FACTS) devices such as the static var compensator (SVC) and the static synchronous compensator (STATCOM), the wind turbine itself can also provide a certain amount...

  17. GAS FLOW CONTROL SYSTEM IN REACTIVE MAGNETRON SPUTTERING TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    I. M. Klimovich

    2015-01-01

    Full Text Available  It is known that the discharge parameters and the chemical composition of the particles flux impinging onto the substrate during a reactive magnetron sputtering are unstable. As a result spontaneous transitions between the «metal» mode of the target surface and the «poisoned» mode of the target surface have been observed. This leads to nonrepeatability of the coating compositions from process to process. The aim of this work is to design a gas flow control system for reactive sputtering processes. The control system allows to maintain a steady nonequilibrium state of the magnetron discharge in transition mode where the chemical state of the target surface is unstable. The intensities of spectral lines of the discharge spectrum are proposed as control parameters. Photodiode detectors were used for registration of intensities of spectral lines. A gas flow control system regulates argon and reactive gas flow automatically, using feedback signals from photodiode detectors on the intensities of the spectral lines, vacuum gauge, ion current sensor, sensors of discharge current and voltage. As an example, the process of reactive magnetron Ti-Al-N deposition is considered. The following discharge parameters are controlled during sputtering a composite target based on Ti with Al cylindrical inserts: current, voltage, total pressure of a gas mixture, substrate temperature, bias voltage and current of the substrate. Nitrogen flow was controlled by the spectral line intensity of titanium TiI 506,5 nm. The value of the line intensity is connected with the value of reactivity. Elemental composition and structure of the Ti-Al-N coatings were studied using Rutherford backscattering spectroscopy, scanning electron microscopy and X-ray diffraction. It was found, that stoichiometric Ti-Al-N coatings have a globular structure, enhanced hardness and low friction coefficient in contrast to Ti-Al-N coatings with nonstoichiometric composition, which have a

  18. Towards a global system of compensation for transboundary nuclear damage: reflexions on the interrelationship of civil and international state liability

    International Nuclear Information System (INIS)

    Handl, G.

    1993-01-01

    International state liability is an essential complementary element of any global and comprehensive nuclear compensation system. Civil liability alone will not be able to fully compensate victims of a nuclear accident and will therefore not fully internalize the costs of nuclear activities. To make it effective and politically acceptable, state liability must be fully integrated procedurally with any civil liability system as a last tier of compensation following a simple process for handling together both civil and state liability claims at the international level, with individuals being able to sue Installation States. 69 refs

  19. Sampled data CT system including analog filter and compensating digital filter

    International Nuclear Information System (INIS)

    Glover, G. H.; DallaPiazza, D. G.; Pelc, N. J.

    1985-01-01

    A CT scanner in which the amount of x-ray information acquired per unit time is substantially increased by using a continuous-on x-ray source and a sampled data system with the detector. An analog filter is used in the sampling system for band limiting the detector signal below the highest frequency of interest, but is a practically realizable filter and is therefore non-ideal. A digital filter is applied to the detector data after digitization to compensate for the characteristics of the analog filter, and to provide an overall filter characteristic more nearly like the ideal

  20. A new method to compensate for counting losses due to system dead time

    Energy Technology Data Exchange (ETDEWEB)

    Karabidak, S.M. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)], E-mail: salihm@ktu.edu.tr; Cevik, U. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey); University of Antwerp, Department of Chemistry, B-2610 Antwerpen (Belgium); Kaya, S. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)

    2009-05-21

    Determination of count losses and pile-up pulse effects in quantitative and qualitative analysis became a vital step in various analyses. Therefore, compensating for counting losses is of importance. These counting losses are due to the pulse pile-up, paralyzable and non-paralyzable system dead time or a combination of these mechanisms. In this work, a new method is suggested for the correction of dead time losses resulting from the above mechanisms. For this purpose, a source code was developed. It was found that the peaking time was an important parameter over system dead time. The method suggested seems to be more effective even at high count rate.

  1. Adaptive compensation of multiple distortions with only pilot tones for flexible coherent transmission systems

    Science.gov (United States)

    Cui, Sheng; Xu, Mengran; Fang, Xiaozhi; Ke, Changjian; Liu, Deming

    2015-01-01

    In this paper an adaptive multiple distortions compensation method based on amplitude modulated pilot tones (AM-PTs) is proposed for flexible single carrier optical coherent transmission systems. At the transmitter a pair of AM-PTs are generated from the optical carrier and inserted at the double sidebands of the optical signal. At the receiver the field of the AM-PT is recovered with the main signal and fully utilized for the estimation of both linear and ultra-fast nonlinear distortions including chromatic dispersion (CD), laser phase noise (LPN), local oscillator frequency offset (LFO) and cross phase modulation (XPM), thus avoiding the spectral efficiency and complexity cost due to the insertion of different pilots for the estimation of different distortions. The four distortions can be estimate from a simple analytical procedure or directly from the AM-PT fields. Thus the distortion estimation and XPM compensation process can be greatly simplified compared to the non-pilot-aided compensation algorithms. Furthermore the distortion estimation accuracy is not compromised and in inhomogeneous networks the XPM estimation accuracy is even better compared to the previous pilot-aided methods. Numerical simulations are then used to demonstrate the effectiveness and efficiency of this method.

  2. Advanced linear and nonlinear compensations for 16QAM SC-400G unrepeatered transmission system

    Science.gov (United States)

    Zhang, Junwen; Yu, Jianjun; Chien, Hung-Chang

    2018-02-01

    Digital signal processing (DSP) with both linear equalization and nonlinear compensations are studied in this paper for the single-carrier 400G system based on 65-GBaud 16-quadrature amplitude modulation (QAM) signals. The 16-QAM signals are generated and pre-processed with pre-equalization (Pre-EQ) and Look-up-Table (LUT) based pre-distortion (Pre-DT) at the transmitter (Tx)-side. The implementation principle of training-based equalization and pre-distortion are presented here in this paper with experimental studies. At the receiver (Rx)-side, fiber-nonlinearity compensation based on digital backward propagation (DBP) are also utilized to further improve the transmission performances. With joint LUT-based Pre-DT and DBP-based post-compensation to mitigate the opto-electronic components and fiber nonlinearity impairments, we demonstrate the unrepeatered transmission of 1.6Tb/s based on 4-lane 400G single-carrier PDM-16QAM over 205-km SSMF without distributed amplifier.

  3. Notes on some experiments on the application of subtractive compensation to USGS seismic magnetic tape recording and playback systems

    Science.gov (United States)

    Eaton, Jerry P.

    1975-01-01

    The purpose of these experiments is to lay the groundwork for the implementation of subtractive compensation of the USGS seismic network tape playbacks utilizing the Develco model 6203 discriminators at a x1 playback speed. Although the Develco discriminators were designed for this application and a matching Develco compensation discriminator was purchased, effective use of this system for subtractive compensation has been blocked by the inadequate (frequency dependent) matching of the phase of the compensation signal to that of the data signal at the point compensation is carried out in the data discriminators. John Van Schaack has ameliorated the phase mismatch problem by an empirical alteration of the compensation discriminator input bandpass filter. We have selected a set (of eight) Develco discriminators and adjusted their compensation signal input levels to minimize spurious signals (noise) originating from tape speed irregularities. The sensitivity of the data discriminators was adjusted so that deviations of +125 Hz and -125 Hz produced output signals of +2.00 volts and -2.00 volts, respectively. The eight data discriminators are driven by a multiplex signal on a single tape track (subcarriers 680, 1020, 1360, 1700, 2040, 2380, 2720, and 3060 Hz). The Develco-supplied compensation discriminator requires an unmodulated 3125 Hz signal on a separate tape track.

  4. Transient Stability Improvement in Multi-Machine System Using Power System Stabilizer (PSS) and Static Var Compensator (SVC)

    OpenAIRE

    Khoshnaw Khalid Hama Saleh; Ergun Ercelebi

    2015-01-01

    Increasingly complex modern power systems require stability, especially for transient and small disturbances. Transient stability plays a major role in stability during fault and large disturbance. This paper compares a power system stabilizer (PSS) and static Var compensator (SVC) to improve damping oscillation and enhance transient stability. The effectiveness of a PSS connected to the exciter and/or governor in damping electromechanical oscillations of isolated synchro...

  5. [Reactive collisions of high-temperature systems]: Progress report

    International Nuclear Information System (INIS)

    Graff, M.M.

    1988-01-01

    We are developing an experiment to study the reactive collisions of systems with large activation barriers or endothermicities. The basis design involves the collision of fast radicals with a stable reactant gas (hydrogen) in a collision cell. Initially, products will be detected by ionization and mass analysis. Later, laser-induced fluorescence will be used to probe internal states of products. Studies will include an investigation of rotational effects by comparing results for rotational levels J = O and 1 of molecular hydrogen. 2 figs

  6. Progress in Medicine: Compensation and medical negligence in India: Does the system need a quick fix or an overhaul?

    Directory of Open Access Journals (Sweden)

    Meghana S Chandra

    2016-01-01

    Full Text Available In a recent judgment on medical negligence, the Supreme Court awarded compensation amounting to Rs. 11 crore to a victim, which was to be paid by the doctors and the private hospital deemed responsible for the wrongful death of a patient. This landmark decision was by far the largest compensation award in the history of Indian medical negligence litigation. Hence, the process of calculating compensation for medical negligence has received great attention and debate, largely due to the impact that it is going to have on the practice of medicine within the country, in the near future. However, the method of calculation of compensation is unpredictable as it varies hugely across different cases, courts and tribunals resulting, in a loss of faith in the system, protracted litigation, and frequent appeals. With over 80% of India's healthcare being provided by the private sector, predictability and uniformity in the regulation of compensation in medical negligence would benefit the victims and the doctors concerned. A basic knowledge of how medical negligence compensation is calculated and adjudicated in the judicial courts of India will aid a doctor in planning his/her professional indemnity insurance, as well as in practicing his/her profession without undue worry about facing litigation for alleged medical negligence. This article addresses the merits and demerits of large compensation awards, and also discusses whether the system is broken, needs a quick fix, or a massive overhaul.

  7. Progress in Medicine: Compensation and medical negligence in India: Does the system need a quick fix or an overhaul?

    Science.gov (United States)

    Chandra, Meghana S; Math, Suresh Bada

    2016-10-01

    In a recent judgment on medical negligence, the Supreme Court awarded compensation amounting to Rs. 11 crore to a victim, which was to be paid by the doctors and the private hospital deemed responsible for the wrongful death of a patient. This landmark decision was by far the largest compensation award in the history of Indian medical negligence litigation. Hence, the process of calculating compensation for medical negligence has received great attention and debate, largely due to the impact that it is going to have on the practice of medicine within the country, in the near future. However, the method of calculation of compensation is unpredictable as it varies hugely across different cases, courts and tribunals resulting, in a loss of faith in the system, protracted litigation, and frequent appeals. With over 80% of India's healthcare being provided by the private sector, predictability and uniformity in the regulation of compensation in medical negligence would benefit the victims and the doctors concerned. A basic knowledge of how medical negligence compensation is calculated and adjudicated in the judicial courts of India will aid a doctor in planning his/her professional indemnity insurance, as well as in practicing his/her profession without undue worry about facing litigation for alleged medical negligence. This article addresses the merits and demerits of large compensation awards, and also discusses whether the system is broken, needs a quick fix, or a massive overhaul.

  8. Emergence of chaos in a spatially confined reactive system

    Science.gov (United States)

    Voorsluijs, Valérie; De Decker, Yannick

    2016-11-01

    In spatially restricted media, interactions between particles and local fluctuations of density can lead to important deviations of the dynamics from the unconfined, deterministic picture. In this context, we investigated how molecular crowding can affect the emergence of chaos in small reactive systems. We developed to this end an amended version of the Willamowski-Rössler model, where we account for the impenetrability of the reactive species. We analyzed the deterministic kinetics of this model and studied it with spatially-extended stochastic simulations in which the mobility of particles is included explicitly. We show that homogeneous fluctuations can lead to a destruction of chaos through a fluctuation-induced collision between chaotic trajectories and absorbing states. However, an interplay between the size of the system and the mobility of particles can counterbalance this effect so that chaos can indeed be found when particles diffuse slowly. This unexpected effect can be traced back to the emergence of spatial correlations which strongly affect the dynamics. The mobility of particles effectively acts as a new bifurcation parameter, enabling the system to switch from stationary states to absorbing states, oscillations or chaos.

  9. Compensation for HPA nonlinearity and I/Q imbalance in MIMO beamforming systems

    KAUST Repository

    Qi, Jian

    2010-10-01

    In this paper, we investigate the effects of high-power amplifier (HPA) nonlinearity and in-phase and quadrature-phase (I/Q) imbalance on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems. Specifically, we propose a compensation method for HPA nonlinearity and I/Q imbalance together in MIMO TB systems. The performance of the MIMO TB system under study is evaluated in terms of the average symbol error probability (SEP) and system capacity, considering transmission over uncorrelated frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects of several system parameters, such as the HPA parameters, image-leakage ratio, numbers of transmit and receive antennas, length of pilot symbols, and modulation order of phase-shift keying (PSK), on performance. © 2010 IEEE.

  10. Compensating active power imbalances in power system with large-scale wind power penetration

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Altin, Müfit

    2016-01-01

    Large-scale wind power penetration can affectthe supply continuity in the power system. This is a matterof high priority to investigate, as more regulating reservesand specified control strategies for generation control arerequired in the future power system with even more highwind power...... penetration. This paper evaluates the impact oflarge-scale wind power integration on future power systems.An active power balance control methodology is usedfor compensating the power imbalances between thedemand and the generation in real time, caused by windpower forecast errors. The methodology...... for the balancepower control of future power systems with large-scalewind power integration is described and exemplified consideringthe generation and power exchange capacities in2020 for Danish power system....

  11. Compensation methods applied in current control schemes for large AC drive systems

    DEFF Research Database (Denmark)

    Rus, D. C.; Preda, N. S.; Teodorescu, Remus

    2012-01-01

    The paper deals with modified PI current control structures for large AC drive systems which use surface mounted permanent magnet synchronous machines or squirrel-cage induction motors supplied with voltage source inverters. In order to reduce the power losses caused by high frequency switching...... of the semiconductor devices, various compensation methods are used and a modified structure for a PI current controller is proposed, to reduce the switching frequency of the inverter for the same operating frequency of the drive. Simulation, experimental development and test results are presented in order...

  12. Development of the combustion engineering reactivity analyzer system

    International Nuclear Information System (INIS)

    Hoffspiegel, P.; Kaplan, G.; Long, S.; Reum, J.; Rohr, P.

    1988-01-01

    The C-E Reactivity Analyzer (CERA trademark) is an interactive, personal computer based, low power physics data collection and reduction system developed to support pressurized water reactor test programs. The CERA system consists of hardware and software to acquire, digitize, and analyze data for the isothermal temperature coefficient (ITC) and control rod bank worth measurements. The CERA system uses expert-level data analysis algorithms to assist the plant reactor engineer in determining measured values of the ITC and rod bank worths. Statistical, qualitative, and quantitative evaluations of test data fidelity are also provided. The CERA data analysis methodology is a significant advance in speed, accuracy, and test anomaly identification over the standard method of manual data reduction using strip charts and hand-collected data

  13. Financial compensation for radiotherapy-related adverse events in a judicial system where proof of medical negligence is not required

    International Nuclear Information System (INIS)

    Nyandoto, Paul; Muhonen, Timo; Hakala, Tapani; Dombrowski, Mitchell P.; Joensuu, Heikki

    2001-01-01

    Purpose: To examine the frequency of adverse events related to radiation therapy that lead to financial compensation in a judicial system that is not based on litigation in court but on statutory insurance where proof of medical negligence is not required for obtaining compensation. Methods and Materials: In Finland, an injured patient does not sue through the courts, but submits an insurance claim to the Patient Insurance Association. Proof of medical negligence is not required for obtaining compensation. We reviewed all filed claims associated with radiotherapy presented to the Patient Insurance Association from May 1987 to January 1999. During this time period, 1,732,000 patient visits to radiation therapy units were made, and the estimated number of radiotherapy treatments was 86,600. The data collected included descriptions of the adverse events, examination of the radiation therapy procedures followed, assessment of the causal relation of the event to radiotherapy by the therapists involved and by independent reviewers, and the sums used for compensation. Results: Only 102 patients (about 0.1%) had filed a claim for financial compensation, and in 18 (0.02%) cases the claim led to compensation. The mean national annual expenditure used for compensation was $35,200, and the sums paid in single cases ranged from $310 to $287,430 (median, $1,970). The expenditure used for compensating adverse radiation events was about $4 per treated patient, which is about 0.3% of all radiation therapy costs. Conclusions: The frequency of radiation therapy injuries that are financially compensated can remain low in an insurance-based judicial system where no litigation or attorneys are involved

  14. modeling and analysis of a three-phase solid-state var compensator

    African Journals Online (AJOL)

    Abstract. The problems associated with the flow of reactive power in transmission and distribution lines are well known. Several methods of var compensation have been applied in solv- ing these problems. This paper examines the performance of a three-phase solid-state var compensator employed in the power system for ...

  15. Dispersion compensation of fiber optic communication system with direct detection using artificial neural networks (ANNs)

    Science.gov (United States)

    Maghrabi, Mahmoud M. T.; Kumar, Shiva; Bakr, Mohamed H.

    2018-02-01

    This work introduces a powerful digital nonlinear feed-forward equalizer (NFFE), exploiting multilayer artificial neural network (ANN). It mitigates impairments of optical communication systems arising due to the nonlinearity introduced by direct photo-detection. In a direct detection system, the detection process is nonlinear due to the fact that the photo-current is proportional to the absolute square of the electric field intensity. The proposed equalizer provides the most efficient computational cost with high equalization performance. Its performance is comparable to the benchmark compensation performance achieved by maximum-likelihood sequence estimator. The equalizer trains an ANN to act as a nonlinear filter whose impulse response removes the intersymbol interference (ISI) distortions of the optical channel. Owing to the proposed extensive training of the equalizer, it achieves the ultimate performance limit of any feed-forward equalizer (FFE). The performance and efficiency of the equalizer is investigated by applying it to various practical short-reach fiber optic communication system scenarios. These scenarios are extracted from practical metro/media access networks and data center applications. The obtained results show that the ANN-NFFE compensates for the received BER degradation and significantly increases the tolerance to the chromatic dispersion distortion.

  16. Energy Storage Characteristic Analysis of Voltage Sags Compensation for UPQC Based on MMC for Medium Voltage Distribution System

    Directory of Open Access Journals (Sweden)

    Yongchun Yang

    2018-04-01

    Full Text Available The modular multilevel converter (MMC, as a new type of voltage source converter, is increasingly used because it is a distributed storage system. There are many advantages of using the topological structure of the MMC on a unified power quality controller (UPQC, and voltage sag mitigation is an important use of the MMC energy storage system for the power quality compensation process. In this paper, based on the analysis of the topology of the MMC, the essence of energy conversion in a UPQC of voltage sag compensation is analyzed; then, the energy storage characteristics are calculated and analyzed to determine the performance index of voltage sag compensation; in addition, the simulation method is used to verify the voltage sag compensation characteristics of the UPQC; finally, an industrial prototype of the UPQC based on an MMC for 10 kV of medium voltage distribution network has been developed, and the basic functions of UPQC have been tested.

  17. Photovoltaic power converter system with a controller configured to actively compensate load harmonics

    Science.gov (United States)

    de Rooij, Michael Andrew; Steigerwald, Robert Louis; Delgado, Eladio Clemente

    2008-12-16

    Photovoltaic power converter system including a controller configured to reduce load harmonics is provided. The system comprises a photovoltaic array and an inverter electrically coupled to the array to generate an output current for energizing a load connected to the inverter and to a mains grid supply voltage. The system further comprises a controller including a first circuit coupled to receive a load current to measure a harmonic current in the load current. The controller includes a second circuit to generate a fundamental reference drawn by the load. The controller further includes a third circuit for combining the measured harmonic current and the fundamental reference to generate a command output signal for generating the output current for energizing the load connected to the inverter. The photovoltaic system may be configured to compensate harmonic currents that may be drawn by the load.

  18. Coordinated setting of stabilizers for synchronous generators and static var compensators in multimachine systems

    Energy Technology Data Exchange (ETDEWEB)

    Simoes Costa, A.J.A.; Silva, A.S.; Freitas, F.D. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Eletrica

    1994-12-31

    Two distinct approaches for the coordinated setting of multimachine power system controllers are presented. The first strategy is based on the re-allocation of the poles related to the electromechanical modes of the system through decentralized control. The second method is a coordinated global procedure based on structurally constrained optimal control. Both approaches considered power system stabilizers and supplementary signals for static var compensators as the controllers to be adjusted. Other types of controllers, such as FACTS devices, can also be tuned by using the proposed techniques. A 13-machine, 77-bus power system which is based on the Brazilian South-Southeast interconnected network is employed to assess the performance of the proposed methods. (author) 14 refs., 1 fig., 7 tabs.

  19. Analysis of the Influence of Compensation Capacitance Errors of a Wireless Power Transfer System with SS Topology

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2017-12-01

    Full Text Available In this study, in order to determine the reasonable accuracy of the compensation capacitances satisfying the requirements on the output characteristics for a wireless power transfer (WPT system, taking the series-series (SS compensation structure as an example, the calculation formulas of the output characteristics, such as the power factor, output power, coil transfer efficiency, and capacitors’ voltage stress, are given under the condition of incomplete compensation according to circuit theory. The influence of compensation capacitance errors on the output characteristics of the system is then analyzed. The Taylor expansions of the theoretical formulas are carried out to simplify the formulas. The influence degrees of compensation capacitance errors on the output characteristics are calculated according to the simplified formulas. The reasonable error ranges of the compensation capacitances are then determined according to the requirements of the output characteristics of the system in the system design. Finally, the validity of the theoretical analysis and the simplified processing is verified through experiments. The proposed method has a certain guiding role for practical engineering design, especially in mass production.

  20. Modern Reactive Power Generators

    Science.gov (United States)

    Chubraeva, L.; Timofeev, S.

    2018-02-01

    The paper reviews main stages of development of reactive power generators, describes the 1-st and 2-nd generation of synchronous condensers with conventional cooling systems and a new generation – superconductive synchronous condensers. Asynchronous non- salient pole condensers expand the class of rotating compensating devices. Comparison of dynamic performance of conventional synchronous condensers, cryogenic condensers and SVC is presented. The variant of a model 5 MVA HTSC synchronous condenser intended for wind power plants is described.

  1. Two-stage open-loop velocity compensating method applied to multi-mass elastic transmission system

    Directory of Open Access Journals (Sweden)

    Zhang Deli

    2014-02-01

    Full Text Available In this paper, a novel vibration-suppression open-loop control method for multi-mass system is proposed, which uses two-stage velocity compensating algorithm and fuzzy I + P controller. This compensating method is based on model-based control theory in order to provide a damping effect on the system mechanical part. The mathematical model of multi-mass system is built and reduced to estimate the velocities of masses. The velocity difference between adjacent masses is calculated dynamically. A 3-mass system is regarded as the composition of two 2-mass systems in order to realize the two-stage compensating algorithm. Instead of using a typical PI controller in the velocity compensating loop, a fuzzy I + P controller is designed and its input variables are decided according to their impact on the system, which is different from the conventional fuzzy PID controller designing rules. Simulations and experimental results show that the proposed velocity compensating method is effective in suppressing vibration on a 3-mass system and it has a better performance when the designed fuzzy I + P controller is utilized in the control system.

  2. A Chemo-Mechanical Model of Diffusion in Reactive Systems

    Directory of Open Access Journals (Sweden)

    Kerstin Weinberg

    2018-02-01

    Full Text Available The functional properties of multi-component materials are often determined by a rearrangement of their different phases and by chemical reactions of their components. In this contribution, a material model is presented which enables computational simulations and structural optimization of solid multi-component systems. Typical Systems of this kind are anodes in batteries, reactive polymer blends and propellants. The physical processes which are assumed to contribute to the microstructural evolution are: (i particle exchange and mechanical deformation; (ii spinodal decomposition and phase coarsening; (iii chemical reactions between the components; and (iv energetic forces associated with the elastic field of the solid. To illustrate the capability of the deduced coupled field model, three-dimensional Non-Uniform Rational Basis Spline (NURBS based finite element simulations of such multi-component structures are presented.

  3. Reactivity requirements and safety systems for heavy water reactors

    International Nuclear Information System (INIS)

    Kati, S.L.; Rustagi, R.S.

    1977-01-01

    The natural uranium fuelled pressurised heavy water reactors are currently being installed in India. In the design of nuclear reactors, adequate attention has to be given to the safety systems. In recent years, several design modifications having bearing on safety, in the reactor processes, protective and containment systems have been made. These have resulted either from new trends in safety and reliability standards or as a result of feed-back from operating reactors of this type. The significant areas of modifications that have been introduced in the design of Indian PHWR's are: sophisticated theoretical modelling of reactor accidents, reactivity control, two independent fast acting systems, full double containment and improved post-accident depressurisation and building clean-up. This paper brings out the evolution of design of safety systems for heavy water reactors. A short review of safety systems which have been used in different heavy water reactors, of varying sizes, has been made. In particular, the safety systems selected for the latest 235 MWe twin reactor unit station in Narora, in Northern India, have been discussed in detail. Research and Development efforts made in this connection are discussed. The experience of design and operation of the systems in Rajasthan and Kalpakkam reactors has also been outlined

  4. An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication

    Science.gov (United States)

    MinhHai, Tran; Rie, Saotome; Suzuki, Taisaku; Wada, Tomohisa

    2016-01-01

    We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1) estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2) symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically. PMID:27057558

  5. Robust control of nonlinear flexible multibody systems using quaternion feedback and dissipative compensation

    Science.gov (United States)

    Kelkar, Atul G.; Joshi, Suresh M.

    1994-01-01

    Global asymptotic stability of a class of nonlinear multibody flexible space structures under dissipative compensation is established. Two cases are considered. The first case allows unlimited nonlinear motions of the entire system and uses quaternion feedback. The second case assumes that the central body motion is in the linear range although the other bodies can undergo unrestricted nonlinear motion. The stability is proved to be robust to the inherent modeling nonlinearities and uncertainties. Furthermore, for the second case, the stability is also shown to be robust to certain actuator and sensor nonlinearities. The stability proofs use the Lyapunov approach and exploit the inherent passivity of such systems. The results are applicable to a wide class of systems, including flexible space structures with articulated flexible appendages.

  6. An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication

    Directory of Open Access Journals (Sweden)

    Tran MinhHai

    2016-01-01

    Full Text Available We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1 estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2 symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically.

  7. An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication.

    Science.gov (United States)

    MinhHai, Tran; Rie, Saotome; Suzuki, Taisaku; Wada, Tomohisa

    2016-01-01

    We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1) estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2) symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically.

  8. Technology of VAr Compensators for Induction Generator Applications in Wind Energy Conversion Systems

    OpenAIRE

    A. F. Zobaa; K. A. Nigim; R. C. Bansal

    2006-01-01

    Many of today utility interconnected wind farms use induction generator (IG) to convert the captured wind mechanical power into electricity. Induction generator has some advantages over the synchronous generator (SG). The main advantages are its robustness and its capability to be synchronized directly to the grid. The main disadvantage, however, is its dependency on the grid for supplying its own reactive power ‘VAr’. Whether fixed or adjustable VAr systems are connected across its terminal,...

  9. An Optimal Reactive Power Control Strategy for a DFIG-Based Wind Farm to Damp the Sub-Synchronous Oscillation of a Power System

    Directory of Open Access Journals (Sweden)

    Bin Zhao

    2014-05-01

    Full Text Available This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capacitive compensation transmission system. First, the damping effect of the reactive power control of the DFIG-based wind farms was theoretically analyzed, and a transfer function between turbogenerator speed and the output reactive power of the wind farms was introduced to derive the analytical expression of the damping coefficient. The phase range to obtain positive damping was determined. Second, the PID phase compensation parameters of the auxiliary damping controller were optimized by a genetic algorithm to obtain the optimum damping in the entire subsynchronous frequency band. Finally, the validity and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory. Theoretical analysis and simulation results show that this derived damping factor expression and the condition of the positive damping can effectively analyze their impact on the system sub-synchronous oscillations, the proposed wind farms reactive power additional damping control strategy can provide the optimal damping effect over the whole sub-synchronous frequency band, and the control effect is better than the active power additional damping control strategy based on the power system stabilizator.

  10. Local Dynamic Reactive Power for Correction of System Voltage Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

    2008-12-01

    Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results

  11. LATENCY DETERMINATION AND COMPENSATION IN REAL-TIME GNSS/INS INTEGRATED NAVIGATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    P. D. Solomon

    2012-09-01

    Full Text Available Unmanned Aerial Vehicle (UAV technology is now commonplace in many defence and civilian environments. However, the high cost of owning and operating a sophisticated UAV has slowed their adoption in many commercial markets. Universities and research groups are actively experimenting with UAVs to further develop the technology, particularly for automated flying operations. The two main UAV platforms used are fixed-wing and helicopter. Helicopter-based UAVs offer many attractive features over fixed-wing UAVs, including vertical take-off, the ability to loiter, and highly dynamic flight. However the control and navigation of helicopters are significantly more demanding than those of fixed-wing UAVs and as such require a high bandwidth real-time Position, Velocity, Attitude (PVA navigation system. In practical Real-Time Navigation Systems (RTNS there are delays in the processing of the GNSS data prior to the fusion of the GNSS data with the INS measurements. This latency must be compensated for otherwise it degrades the solution of the navigation filter. This paper investigates the effect of latency in the arrival time of the GNSS data in a RTNS. Several test drives and flights were conducted with a low-cost RTNS, and compared with a high quality GNSS/INS solution. A technique for the real-time, automated and accurate estimation of the GNSS latency in low-cost systems was developed and tested. The latency estimates were then verified through cross-correlation with the time-stamped measurements from the reference system. A delayed measurement Extended Kalman Filter was then used to allow for the real-time fusing of the delayed measurements, and then a final system developed for on-the-fly measurement and compensation of GNSS latency in a RTNS.

  12. Compressed sensing techniques for receiver based post-compensation of transmitter's nonlinear distortions in OFDM systems

    KAUST Repository

    Owodunni, Damilola S.

    2014-04-01

    In this paper, compressed sensing techniques are proposed to linearize commercial power amplifiers driven by orthogonal frequency division multiplexing signals. The nonlinear distortion is considered as a sparse phenomenon in the time-domain, and three compressed sensing based algorithms are presented to estimate and compensate for these distortions at the receiver using a few and, at times, even no frequency-domain free carriers (i.e. pilot carriers). The first technique is a conventional compressed sensing approach, while the second incorporates a priori information about the distortions to enhance the estimation. Finally, the third technique involves an iterative data-aided algorithm that does not require any pilot carriers and hence allows the system to work at maximum bandwidth efficiency. The performances of all the proposed techniques are evaluated on a commercial power amplifier and compared. The error vector magnitude and symbol error rate results show the ability of compressed sensing to compensate for the amplifier\\'s nonlinear distortions. © 2013 Elsevier B.V.

  13. Carrier Frequency Offset Estimation and I/Q Imbalance Compensation for OFDM Systems

    Directory of Open Access Journals (Sweden)

    M. Omair Ahmad

    2007-01-01

    Full Text Available Two types of radio-frequency front-end imperfections, that is, carrier frequency offset and the inphase/quadrature (I/Q imbalance are considered for orthogonal frequency division multiplexing (OFDM communication systems. A preamble-assisted carrier frequency estimator is proposed along with an I/Q imbalance compensation scheme. The new frequency estimator reveals the relationship between the inphase and the quadrature components of the received preamble and extracts the frequency offset from the phase shift caused by the frequency offset and the cross-talk interference due to the I/Q imbalance. The proposed frequency estimation algorithm is fast, efficient, and robust to I/Q imbalance. An I/Q imbalance estimation/compensation algorithm is also presented by solving a least-square problem formulated using the same preamble as employed for the frequency offset estimation. The computational complexity of the I/Q estimation scheme is further reduced by using part of the short symbols with a little sacrifice in the estimation accuracy. Computer simulation and comparison with some of the existing algorithms are conducted, showing the effectiveness of the proposed method.

  14. A novel disturbance-observer based friction compensation scheme for ball and plate system.

    Science.gov (United States)

    Wang, Yongkun; Sun, Mingwei; Wang, Zenghui; Liu, Zhongxin; Chen, Zengqiang

    2014-03-01

    Friction is often ignored when designing a controller for the ball and plate system, which can lead to steady-error and stick-slip phenomena, especially for the small amplitude command. It is difficult to achieve high-precision control performance for the ball and plate system because of its friction. A novel reference compensation strategy is presented to attenuate the aftereffects caused by the friction. To realize this strategy, a linear control law is proposed based on a reduced-order observer. Neither the accurate friction model nor the estimation of specific characteristic parameters is needed in this design. Moreover, the describing function method illustrates that the limit cycle can be avoided. Finally, the comparative mathematical simulations and the practical experiments are used to validate the effectiveness of the proposed method. © 2013 ISA Published by ISA All rights reserved.

  15. Compensated Row-Column Ultrasound Imaging System Using Multilayered Edge Guided Stochastically Fully Connected Random Fields.

    Science.gov (United States)

    Ben Daya, Ibrahim; Chen, Albert I H; Shafiee, Mohammad Javad; Wong, Alexander; Yeow, John T W

    2017-09-06

    The row-column method received a lot of attention for 3-D ultrasound imaging. By reducing the number of connections required to address the 2-D array and therefore reducing the amount of data to handle, this addressing method allows for real time 3-D imaging. Row-column still has its limitations: the issues of sparsity, speckle noise inherent to ultrasound, the spatially varying point spread function, and the ghosting artifacts inherent to the row-column method must all be taken into account when building a reconstruction framework. In this research, we build on a previously published system and propose an edge-guided, compensated row-column ultrasound imaging system that incorporates multilayered edge-guided stochastically fully connected conditional random fields to address the limitations of the row-column method. Tests carried out on simulated and real row-column ultrasound images show the effectiveness of our proposed system over other published systems. Visual assessment show our proposed system's potential at preserving edges and reducing speckle. Quantitative analysis shows that our proposed system outperforms previously published systems when evaluated with metrics such as Peak Signal-to-Noise Ratio, Coefficient of Correlation, and Effective Number of Looks. These results show the potential of our proposed system as an effective tool for enhancing 3-D row-column imaging.

  16. Impaired systemic vascular reactivity & raised high-sensitivity C reactive protein levels in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Parul Khare

    2016-01-01

    Interpretation & conclusions: Our findings showed raised hs CRP levels and impaired systemic vascular reactivity in COPD patients. Whether these may increase the risk of cardiovascular disease in COPD patients need to be confirmed in future studies with large sample size and appropriate study design.

  17. Dynamic control modeling and simulation of a UPFC–SMES compensator in power systems

    Directory of Open Access Journals (Sweden)

    Saravanan Kandasamy

    2015-12-01

    Full Text Available Flexible AC Transmission Systems (FACTS is granting a new group of advanced power electronic devices emerging for the enhancement of the power system performance. Unified Power Flow Controller (UPFC is a recent version of FACTS devices for power system applications. The back-up energy supply system incorporated with UPFC is providing a complete control of real and reactive power at the same time and hence is competent to improve the performance of an electrical power system. In this article, backup energy supply units such as superconducting magnetic energy storage (SMES are integrated with UPFC. In addition, comparative exploration of UPFC–battery, UPFC–UC and UPFC–SMES performance is evaluated through the vibrant simulation by using MATLAB/Simulink software.

  18. Design of temperature compensating unit for the circulator in 6 MW 4.6 GHz LHCD system

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Chengyao, E-mail: pengcy@ipp.cas.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Techonlogy of China, Hefei, Anhui 230027 (China); Shan, Jiafang; Zhao, Lianmin; Cheng, Min; Jia, Hua; Liu, Fukun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2016-11-15

    Highlights: • Circulator in 6 MW 4.6 GHz LHCD system to protect the klystron is described. • “TCU” is proposed to compensate for the high-power induced temperature drift of the circulator. • Both algorithm and hardware architecture are described. - Abstract: The lower hybrid current drive (LHCD) system is an important part of the Experimental Advanced Superconducting Tokamak (EAST). As the main RF power amplifier, the klystron in the LHCD system is protected by a high power circulator. The temperature of the ferrites in the circulator drifts under high-power condition, which degrades the microwave performance of the circulator and even damages the klystron. In this paper, a design of Temperature Compensating Unit (TCU) is presented and eventually implemented to compensate for the high-power induced temperature drift. Experiments show that the TCU can lead to the high-power steady-state operation of the circulator.

  19. Liability and compensation for oil pollution damage: some current threats to the international convention system

    International Nuclear Information System (INIS)

    Chao Wu

    2002-01-01

    The carriage of oil is indispensable to the industrialized nations. In this respect, the carriage of oil is undertaken as a service to society as a whole with its individual members deriving benefits from its carriage to varying degrees. Consequently, after examining the four Conventions in the international system of compensation for oil pollution from ships, it is argued that the general citizenship of those nations pay, in exceptional cases, for a small share of the risk, which is created in part by the citizens, as users of oil. The paper proposes the creation of a fund of last resort that could be conceived either at a regional level or a national level and financed through (indirect) taxation on the population as a whole. This type of fund could have a wider use in the field of marine pollution and protection of marine resources. (author)

  20. Characteristics of earth faults in power systems with a compensated or an unearthed neutral

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, S.; Lehtonen, M. [VTT Energy, Espoo (Finland); Antila, E. [ABB Transmit Oy (Finland); Stroem, J. [Espoo Electricity Co (Finland); Ingman, S. [Vaasa Electricity Co (Finland)

    1998-08-01

    The most common fault type in the electrical distribution networks is the single phase to earth fault. For instance in the Nordic countries, about 80 % of all faults are of this type. To develop the protection and fault location systems, it is important to obtain real case data of disturbances and faults which occurred in the networks. Therefore, data of fault occurrences have been recorded and analyzed in the medium voltage distribution networks (20 kV) at two substations, of which one has an isolated and the other a compensated neutral. In the occurring disturbances, the traces of phase currents and neutral currents in the beginning of two feeder and the traces of phase voltages and neutral voltage from the voltage measuring bay were recorded. In addition to the measured data, other information of the fault occurrences was also collected (data of the line, cause and location of permanent faults and so on)

  1. Active Speed Compensation Method of Direct Torque Control System and Stability Analysis

    Directory of Open Access Journals (Sweden)

    Rui Li

    2015-02-01

    Full Text Available By analyzing characteristics of the DTC (direct torque control system in electrical driving system, a shortcoming of the classical DTC method is to point out that it is unable to decouple the mutual interference between torque and speed, so that when a running asynchronous motor subjected to an instantaneous impact load, rotor speed and its deviation appears excessive fluctuations that can not be quickly restored to the initial set value. In this research, under conditions that without sensors for measuring load torque and rotor speed, to an electrical drive systems contains DTC devices, a novel ASCC (active speed compensation control method is proposed based on ADRC (active disturbance rejection control theory, on account of DTC model of asynchronous motor, a multiobjective observer is designed to regulate both the speed and the torque, and a proof of asymptotic stability that related this new control systems with the observer is made by theoretical deduction. Finally stimulating results show that this method can overcome the shortcomings of classical DTC system and greatly enhance the ability of the high-speed driving system to deal with unexpected impact loads.

  2. Entropy-enthalpy Compensation of Biomolecular Systems in Aqueous Phase: a Dry Perspective.

    Science.gov (United States)

    Movileanu, Liviu; Schiff, Eric A

    2013-01-01

    We survey thermodynamic measurements on processes involving biological macromolecules in aqueous solution, which illustrate well the ubiquitous phenomenon of entropy-enthalpy compensation. The processes include protein folding/unfolding and ligand binding/unbinding, with compensation temperatures varying by about 50 K around an average near 293 K. We show that incorporating both near-exact entropy-enthalpy compensation (due to solvent relaxation) and multi-excitation entropy (from vibrational quanta) leads to a compensation temperature in water of about 230 K. We illustrate a general procedure for subtracting solvent and environment-related terms to determine the bare Gibbs free energy changes of chemical processes.

  3. Biodecolorization of Reactive Black 5 by laccasemediator system ...

    African Journals Online (AJOL)

    Reactive azo dyes are widely used as textile colorants, typically for cotton dyeing, due to their variety of color shades, and minimal energy consumption. In the present study, commercial laccase from Trametes versicolor was used for the biodecolorization of Reactive Black 5 (RB-5) dye using different redox mediators viz, ...

  4. Motion-blur-compensated structural health monitoring system for tunnels at a speed of 100 km/h

    Science.gov (United States)

    Hayakawa, Tomohiko; Ishikawa, Masatoshi

    2017-04-01

    High quality images of tunnel surfaces are necessary for visual judgment of abnormal parts. Hence, we propose a monitoring system from a vehicle, which is motion-blur-compensated by the back and forth motion of a galvanometer mirror to offset the vehicle speed, prolong exposure time, and take sharp images including detailed textures. As experimental result of the vehicle-mounted system, we confirmed significant improvements in image quality for a few millimeter-sized ordered black-and-white stripes and cracks, by means of motion blur compensation and prolonged exposure time, under the maximum speed allowed in Japan in a standard tunnel of a highway.

  5. An optimal reactive power control strategy for a DFIG-based wind farm to damp the sub-synchronous oscillation of a power system

    DEFF Research Database (Denmark)

    Zhao, Bin; Li, Hui; Wang, Mingyu

    2014-01-01

    and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory. Theoretical analysis and simulation results show that this derived damping factor expression......This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG)-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capacitive...... compensation transmission system. First, the damping effect of the reactive power control of the DFIG-based wind farms was theoretically analyzed, and a transfer function between turbogenerator speed and the output reactive power of the wind farms was introduced to derive the analytical expression...

  6. Modeling and Compensation Design for a Power Hardware-in-the-Loop Simulation of an AC Distribution System: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Prabakar, Kumaraguru [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ainsworth, Nathan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pratt, Annabelle [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Baggu, Murali M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hariri, Ali [Formerly NREL

    2017-10-06

    Power hardware-in-the-loop (PHIL) simulation, where actual hardware under text is coupled with a real-time digital model in closed loop, is a powerful tool for analyzing new methods of control for emerging distributed power systems. However, without careful design and compensation of the interface between the simulated and actual systems, PHIL simulations may exhibit instability and modeling inaccuracies. This paper addresses issues that arise in the PHIL simulation of a hardware battery inverter interfaced with a simulated distribution feeder. Both the stability and accuracy issues are modeled and characterized, and a methodology for design of PHIL interface compensation to ensure stability and accuracy is presented. The stability and accuracy of the resulting compensated PHIL simulation is then shown by experiment.

  7. [Study of pretreatment with ethanol to compensate premature volatilization of self-etch adhesive system].

    Science.gov (United States)

    Li, Hong; Yang, Hongye; Huang, Cui; Deng, Donglai

    2014-06-01

    To evaluate the effect of pretreatment with ethanol on dentin to compensate premature volatilization of self-etch adhesive system. Thirty-two intact human molars were randomly divided into two groups using a table of random numbers (n = 16): A, an acetone-base adhesive (G-bond) and B, an ethanol-based adhesive (Clearfile S(3) bond). Then each group was randomly assigned into foursub groups (n = 4) : group 1, no premature volatilization; group 2, premature volatilization; group 3, premature volatilization + stepwise ethanol pretreatments; and group 4, premature volatilization + absolute ethanol treatment. After composite resin building, microtensile bond strengths (MTBS) of each subgroup were then tested. Fracture modes were classified by stereomicroscopy and representative interface was observed by field-emission scanning electron microscopy (FE-SEM). For adhesive A, there was significant difference on MTBS among different subgroups (P 0.05); neither between group A1 and A3 (P > 0.05). For adhesive B, there was no difference on MTBS among different subgroups (P > 0.05).FE-SEM showed that the main fracture mode was located at the bottom of the hybrid layer for adhesive A groups, the collagen fibrils were capsulated by resin monomers more densely in group A1 and group A3 in comparison with other two subgroups.For adhesive B groups, the main failure modes were at the top of the hybrid layer. Premature volatilization can obviously decrease the bonding strength of acetone-base self-etch adhesives, but has no significant effect on ethanol-based self-etch adhesives. Dentin pretreatment with a series of increasing ethanol concentrations can effectively compensate the adverse effect of premature volatilization of acetone-base self-etch adhesives on bonding strength.

  8. Extremum Seeking Control of Smart Inverters for VAR Compensation

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, Daniel; Negrete-Pincetic, Matias; Stewart, Emma; Auslander, David, M; Callaway, Duncan

    2015-09-04

    Reactive power compensation is used by utilities to ensure customer voltages are within pre-defined tolerances and reduce system resistive losses. While much attention has been paid to model-based control algorithms for reactive power support and Volt Var Optimization (VVO), these strategies typically require relatively large communications capabilities and accurate models. In this work, a non-model-based control strategy for smart inverters is considered for VAR compensation. An Extremum Seeking control algorithm is applied to modulate the reactive power output of inverters based on real power information from the feeder substation, without an explicit feeder model. Simulation results using utility demand information confirm the ability of the control algorithm to inject VARs to minimize feeder head real power consumption. In addition, we show that the algorithm is capable of improving feeder voltage profiles and reducing reactive power supplied by the distribution substation.

  9. 3D optical imagery for motion compensation in a limb ultrasound system

    Science.gov (United States)

    Ranger, Bryan J.; Feigin, Micha; Zhang, Xiang; Mireault, Al; Raskar, Ramesh; Herr, Hugh M.; Anthony, Brian W.

    2016-04-01

    Conventional processes for prosthetic socket fabrication are heavily subjective, often resulting in an interface to the human body that is neither comfortable nor completely functional. With nearly 100% of amputees reporting that they experience discomfort with the wearing of their prosthetic limb, designing an effective interface to the body can significantly affect quality of life and future health outcomes. Active research in medical imaging and biomechanical tissue modeling of residual limbs has led to significant advances in computer aided prosthetic socket design, demonstrating an interest in moving toward more quantifiable processes that are still patient-specific. In our work, medical ultrasonography is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets while greatly reducing cost compared to an MRI-based framework. This paper presents a prototype limb imaging system that uses a medical ultrasound probe, mounted to a mechanical positioning system and submerged in a water bath. The limb imaging is combined with three-dimensional optical imaging for motion compensation. Images are collected circumferentially around the limb and combined into cross-sectional axial image slices, resulting in a compound image that shows tissue distributions and anatomical boundaries similar to magnetic resonance imaging. In this paper we provide a progress update on our system development, along with preliminary results as we move toward full volumetric imaging of residual limbs for prosthetic socket design. This demonstrates a novel multi-modal approach to residual limb imaging.

  10. A comparison of and the compensation for magnetostrictive core inductances in magnetic transducer systems

    International Nuclear Information System (INIS)

    Bartlett, P.A.; Meydan, T.; Lea, S.C.; Moses, A.J.; Williams, P.I.; Landini, G.; Walmsley, A.D.

    2008-01-01

    Magnetostrictive materials have been utilized for the production of ultrasonic frequency vibrations for a number of years. This has particularly been the case in laminated nickel-based ultrasonic dental-scaler cleaning systems. In this study, a comparison has been made between the impedances of a number of magnetostrictive stacks of 50 mmx4 mmx∼0.3 mm strips at frequencies in the range of 10-50 kHz in a coil used for the excitation of a stack in a dental-scaler system. The magnetostrictive stacks tested comprised of potential replacement materials for standard nickel ones. The study showed that it was possible to compensate for the inductive 'imaginary' components of the impedance through the use of a tuned, series capacitance so that only the 'real' resistive component of the impedance remained. This reduced the electrical losses associated with the excitation of the magnetostrictive stacks as a result of the frequency-dependent inductance of the coil system. Consequently, the maximum power transfer from an amplifier to the transducer was increased. Also, the investigation showed how the 'real' component of impedance of the different stacks varied with frequency. In a tuned resonant electrical circuit, the resistive component of the impedance, if considered as a loss, would be the lowest that could be achieved with such a magnetic circuit. Consequently, the losses associated with resonant magnetostrictive devices, like dental scalers, can be reduced

  11. Laboratory and field scale demonstration of reactive barrier systems

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Marozas, D.C.; Cantrell, K.; Stewart, W.

    1996-10-01

    In an effort to devise a cost efficient technology for remediation of uranium contaminated groundwater, the Department of Energy's Uranium Mill Tailings Remedial Action (DOE-UMTRA) Program through Sandia National Laboratories (SNL) fabricated a pilot scale research project utilizing reactive subsurface barriers at an UMTRA site in Durango, Colorado. A reactive subsurface barrier is produced by placing a reactant material (in this experiment, metallic iron) in the flow path of the contaminated groundwater. The reactive media then removes and/or transforms the contaminant(s) to regulatory acceptable levels. Experimental design and results are discussed with regard to other potential applications of reactive barrier remediation strategies at other sites with contaminated groundwater problems

  12. Digital compensation techniques for the effects of time lag in closed-loop simulation using the 6 DOF motion system

    Science.gov (United States)

    Brown, R.

    1982-01-01

    Efforts are continued to develop digital filter compensation schemes for the correction of momentum gains observed in the closed loop simulation of the docking of two satellites using the 6 DOF motion system. Several filters that work well for small delays ( .100ms) and a non-preloaded probe are discussed.

  13. Model-Based Testing of a Reactive System with Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon

    2006-01-01

    In this paper, a reactive and nondeterministic system is tested. This is doneby applying a generic model that has been specified as a configurable Coloured PetriNet. In this way, model-based testing is possible for a wide class of reactive system atthe level of discrete events. Concurrently...

  14. La restricción sobre compensación y la diversidad en estudios de compensación de reactivo; Overcompensation restriction to increase solution diversity in the reactive compensation studios

    Directory of Open Access Journals (Sweden)

    Raúl Nicolás - Carvajal Pérez

    2013-10-01

    Full Text Available El modelo matemático representativo de un problema de compensación de reactivo en un circuito eléctrico de distribución contiene una restricción que limita el máximo valor de reactivo capacitivo que puede ser instalado en cada nodo para que no exista sobre compensación. Esta restricción se aplica a los bancos de condensadores fijos y controlados. En este trabajo se estudia el problema de la compensación óptima de reactivo utilizando un algoritmo genético de uso específico, se analiza como éste brinda la posibilidad de aumentar la diversidad de soluciones para evitar el estatismo y se argumenta el criterio seguido en la formación de la matriz de los cromosomas de realizar la recombinación sin que los hijos hereden, con obligatoriedad, en cada banco, el tamaño de sus progenitores. Entonces se utiliza la restricción de sobre compensación como límite y se escoge aleatoriamente el tamaño del banco .al final del “Crossover”.The mathematical Model of reactive compensation model in Electrical Distribution Circuits include a restriction about maximum compensation value in each node. This restriction is applied to fixed a variable capacitor. This work try about the optimal reactive compensation using Genetic algorithm. Analyze diversity of solutions to avoid the statism. Propose realize crossover without consider the capacitor banks magnitude and then using overcompensation restriction to choose this magnitude in random form. Show the resulties to apply this criteria in a real circuit.

  15. La restricción sobre compensación y la diversidad en estudios de compensación de reactivo Overcompensation restriction to increase solution diversity in the reactive compensation studios

    Directory of Open Access Journals (Sweden)

    Raúl Nicolás Carvajal Pérez

    2013-09-01

    Full Text Available El modelo matemático representativo de un problema de compensación de reactivo en un circuito eléctrico de distribución contiene una restricción que limita el máximo valor de reactivo capacitivo que puede ser instalado en cada nodo para que no exista sobre compensación. Esta restricción se aplica a los bancos de condensadores fijos y controlados. En este trabajo se estudia el problema de la compensación óptima de reactivo utilizando un algoritmo genético de uso específico, se analiza como éste brinda la posibilidad de aumentar la diversidad de soluciones para evitar el estatismo y se argumenta el criterio seguido en la formación de la matriz de los cromosomas de realizar la recombinación sin que los hijos hereden, con obligatoriedad, en cada banco, el tamaño de sus progenitores. Entonces se utiliza la restricción de sobre compensación como límite y se escoge aleatoriamente el tamaño del banco .al final del “Crossover”.Palabras clave: The mathematical Model of reactive compensation model in Electrical Distribution Circuits include a restriction about maximum compensation value in each node. This restriction is applied to fixed a variable capacitor. This work try about the optimal reactive compensation using Genetic algorithm. Analyze diversity of solutions to avoid the statism. Propose realize crossover without consider the capacitor banks magnitude and then using overcompensation restriction to choose this magnitude in random form. Show the resulties to apply this criteria in a real circuit.Key Words:

  16. Deciding between compensated volume balance and real time transient models for pipeline leak detection system

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Renan Martins [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Div. de Explotacao]. E-mail: renan@cenpes.petrobras.com.br

    2000-07-01

    This paper describes a technical procedure to assess a software based leak detection system (LDS), by deciding between a simpler low cost, less effective product, having a fast installation and tuning, and a complex one with high cost and efficiency, which however takes a long time to be properly installed. This is a common decision among the pipeline operating companies, considering that the majority of the lines are short, with single phase liquid flow (which may include batches), basic communication system and instrumentation. Service companies offer realistic solutions for liquid flow, but usually designed to big pipeline networks, flowing multiple batches and allowing multiple fluid entrances and deliveries. Those solutions are sometimes impractical to short pipelines, due to its high cost, as well as long tuning procedures, complex instrumentation, communication and computer requirements. It is intended to approach here the best solution according to its cost. In a practical sense, it means to differentiate the various LDS techniques. Those techniques are available in a considerable number, and they are still spreading, according to the different scenarios. However, two most known and worldwide implemented techniques hold the majority of the market: the Compensated Volume Balance (CVB), which is less accurate, reliable and robust, but cheaper, simpler and faster to install, and the Real Time Transient Model (RTTM), which is very reliable, accurate and robust, but expensive and complex. This work will describe a way to define whether one can use or not a CVB in a pipeline. (author)

  17. Robustness analysis and controller design for static var compensators in power systems

    Science.gov (United States)

    Yu, Xuechun I.

    In the North American electric power interconnection, control systems play a prominent role in the stabilization and reliable operation of the system. With the advent of competition and deregulation, systems are being operated closer than ever to the limits. This setting necessitates a systematic procedure to analyze and design controls in power systems which demonstrate good performance for a range of operating conditions. The current industry practice for the analysis and design of controls consists of conventional linear analysis tools coupled with detailed nonlinear simulation of the designed controls. This approach is time consuming and does not guarantee robustness. In this dissertation, we analyze the robustness of the static var compensator's (SVC's) control setting and design a supplementary damping controller for the SVC based on the structured singular value (SSV or mu), which allows computation of an effective measure for robustness in the presence of real parametric uncertainties. The robustness problem in the SSV framework is set up for the multimachine power system. In this formulation the effect of the parameter variations is captured in terms of the varying elements of the linearized system matrix. The uncertainty bounds on the varying elements are determined by running a series of power flow calculations and performing a polynomial fit. The system robustness in terms of the SSV or mu is examined using both the frequency sweep test and the state space mu test. The results on test systems show that the analysis procedure accurately predicts the range of stable operating conditions which are verified by repeated eigenvalue analysis. Some of the issues that arise in the design of a suitable supplementary controller for the SVC include the choice of the location and voltage level of the SVC, and the choice of the control signals for the supplementary controller. These issues are carefully investigated and incorporated into the design procedure. The

  18. Analysis and Control of STATCOM/SMES Compensator in a Load Variation Conditions

    Directory of Open Access Journals (Sweden)

    Mahmoud Reza Shakarami

    2014-01-01

    Full Text Available The utilization of Flexible AC Transmission System (FACTS devices in a power system can potentially overcome limitations of the present mechanically controlled transmission system. Also, the advanced technology makes it possible to include new energy storage devices in the electrical power system. The integration of Superconducting Magnetic Energy Storage (SMES into Static Synchronous Compensator (STATCOM can lead to increase their flexibility to improve power system dynamic behavior by exchanging both active and reactive powers with power grids. This paper describes structure and behavior of STATCOM/SMES compensator in power systems. A control strategy based on direct Lyapanov method for compensator is used. Moreover, the performance of the STATCOM/SMES compensator in a load variation condition is evaluated by PSCAD/EMTDC software in test system. Also, SMES capacity effects on integrated compensator are investigated.

  19. Development of village doctors in China: financial compensation and health system support.

    Science.gov (United States)

    Hu, Dan; Zhu, Weiming; Fu, Yaqun; Zhang, Minmin; Zhao, Yang; Hanson, Kara; Martinez-Alvarez, Melisa; Liu, Xiaoyun

    2017-07-01

    doctors. But After 1985, the formal health system played a more dominant role in the CHW system including both selection and training of village doctors. China applied various mechanisms to compensate village doctors in different stages. During 1960s and 1970s, the main income source of barefoot doctors was from their villages' collective economy. After 1985 when the rural collective economy collapsed and barefoot doctors were transformed to village doctors, they depended on user fees, especially from drug sale revenues. In the new century, especially after the new round of health system reform in 2009, government subsidy has become an increasing source of village doctors' income. The barefoot doctor policy has played a significant role in providing basic human resources for health and basic health services to rural populations when rural area had great shortages of health resources. The key experiences for this great achievement are the intersection between the community and the formal health system, and sustained and stable financial compensation to the community health workers.

  20. The association between attributions of responsibility for motor vehicle accidents and patient satisfaction: a study within a no-fault injury compensation system.

    Science.gov (United States)

    Thompson, Jason; Berk, Michael; O'Donnell, Meaghan; Stafford, Lesley; Nordfjaern, Trond

    2015-05-01

    This study set out to test the relationship between attributions of responsibility for motor vehicle accidents and satisfaction with personal injury compensation systems. The study analysed survey data from 1394 people injured in a motor vehicle accident who were compensated under a no-fault personal injury compensation system. Patients' ratings of satisfaction with the compensation system across five domains (resolves your issues, keeps you up-to-date, treats you as an individual, cares about you, and overall satisfaction) were analysed alongside patient attributions of responsibility for their accident (not responsible, partly responsible, totally responsible). Postaccident physical and mental health status, age, gender, and duration of compensation claim were controlled for in the analysis. A multivariate analysis of covariance indicated attributions of responsibility for accidents were significantly associated with levels of patient satisfaction across all five domains under study (F (10, 2084) = 3.7, presponsibility for their accidents to others were significantly less satisfied with the injury compensation system than those who attributed responsibility to themselves. Satisfaction with no-fault motor vehicle injury compensation services are associated with patients' attributions of responsibility for their accident. Compensation systems and other rehabilitation services monitoring patient satisfaction should adjust for attributions of responsibility when assessing levels of patient satisfaction between time periods, services, or injured populations. Differences in levels of patient satisfaction observed between compensation or rehabilitation populations may reflect differences in attributions of responsibility for accidents rather than objective service quality. © The Author(s) 2014.

  1. Creative compensation

    International Nuclear Information System (INIS)

    Coll, D.

    1994-01-01

    A discussion is presented of executive compensation in Canada's petroleum industry. Mandatory disclosure of executive compensation and benefits is regulated by the Ontario Securities Commission. Examination of the compensation packages of 80 oilpatch CEOs shows a clear difference in philosophy between large and small companies. Larger companies pay larger salaries, offer pension plans, and reward long-term loyalty. Within smaller companies, compensation tends to be linked with stock performance. Trends in compensation are to lower base salaries with more variables such as bonuses, cash incentives and gain-sharing programs. Increasing shareholder scrutiny is prompting more stringent guidelines on stock option plans. Some companies place performance conditions on stock vesting. Another option is to grant premium priced options to executives, to increase the gains required for the executive to post a profit. Other comapanies are granting stock options to their field personnel, or are granting stock to all employees. Directors are playing an increasing role in executive compensation. 4 tabs

  2. Fiber Nonlinearity Post-Compensation by Optical Phase Conjugation for 40Gb/s CO-OFDM Systems

    International Nuclear Information System (INIS)

    Qiao Yao-Jun; Liu Xue-Jun; Ji Yue-Feng

    2011-01-01

    Fiber nonlinearity impairments in a 40-Gb/s coherent optical orthogonal frequency division multiplexing (COOFDM) system are post-compensated for by a new method of fiber nonlinearity post-compensation (FNPC). The FNPC located before the CO-OFDM receiver includes an optical phase conjugation (OPC) unit and a subsequent 80-km-high nonlinear fiber (HNLF) as a fiber nonlinearity compensator. The OPC unit is based on a four wave mixing effect in a semiconductor optical amplifier. The fiber nonlinearity impairments in the transmission link are post-compensated for after OPC by transmission through the HNLF with a large nonlinearity coefficient. Simulation results show that the nonlinear threshold (NLT) (for Q > 10 dB) can be increased by about 2.5 dB and the maximum Q factor is increased by about 1.2 dB for the single-channel 40-Gb/s CO-OFDM system with periodic dispersion maps. In the 50-GHz channel spacing wavelength-division-multiplexing system, the NLT increases by 1.1 dB, equating to a 0.7 dB improvement for the maximum Q factor. (fundamental areas of phenomenology(including applications))

  3. A compensation method of lever arm effect for tri-axis hybrid inertial navigation system based on fiber optic gyro

    Science.gov (United States)

    Liu, Zengjun; Wang, Lei; Li, Kui; Gao, Jiaxin

    2017-05-01

    Hybrid inertial navigation system (HINS) is a new kind of inertial navigation system (INS), which combines advantages of platform INS, strap-down INS and rotational INS. HINS has a physical platform to isolate the angular motion as platform INS does, HINS also uses strap-down attitude algorithms and applies rotation modulation technique. Tri-axis HINS has three gimbals to isolate the angular motion in the dynamic base, in which way the system can reduce the effects of angular motion and improve the positioning precision. However, the angular motion will affect the compensation of some error parameters, especially for the lever arm effect. The lever arm effect caused by position errors between the accelerometers and rotation center cannot be ignored due to the rapid rotation of inertial measurement unit (IMU) and it will cause fluctuation and stage in velocity in HINS. The influences of angular motion on the lever arm effect compensation are analyzed firstly in this paper, and then the compensation method of lever arm effect based on the photoelectric encoders in dynamic base is proposed. Results of experiments on turntable show that after compensation, the fluctuations and stages in velocity curve disappear.

  4. Software Development Technologies for Reactive, Real-Time, and Hybrid Systems: Summary of Research

    Science.gov (United States)

    Manna, Zohar

    1998-01-01

    This research is directed towards the implementation of a comprehensive deductive-algorithmic environment (toolkit) for the development and verification of high assurance reactive systems, especially concurrent, real-time, and hybrid systems. For this, we have designed and implemented the STCP (Stanford Temporal Prover) verification system. Reactive systems have an ongoing interaction with their environment, and their computations are infinite sequences of states. A large number of systems can be seen as reactive systems, including hardware, concurrent programs, network protocols, and embedded systems. Temporal logic provides a convenient language for expressing properties of reactive systems. A temporal verification methodology provides procedures for proving that a given system satisfies a given temporal property. The research covered necessary theoretical foundations as well as implementation and application issues.

  5. Center for Worker's Compensation Studies

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the NIOSH Center for Workers’ Compensation Studies (CWCS) is to use workers’ compensation data and systems to improve workplace safety and health....

  6. Formation of compensation mechanism of regional enterprises’ human resources regeneration in the labor potential development system

    OpenAIRE

    Alexeev, I.; Voloshyn, O.

    2013-01-01

    The article substantiates the formation principles of administration bodies in implementation of compensation mechanism of human resources regeneration. It defines stages of the preparatory period of forming administration bodies of human resources regeneration with the primary units for training and exploitation of human resources, for which was designed the organizational structure of enterprise’s personnel departments subdivisions. A model of a compensation mechanism for regeneration of...

  7. Real time algorithm temperature compensation in tunable laser / VCSEL based WDM-PON system

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C.......We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C....

  8. Widely Linear Blind Adaptive Equalization for Transmitter IQ-Imbalance/Skew Compensation in Multicarrier Systems

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Zibar, Darko

    2016-01-01

    Simple analytical widely linear complex-valued models for IQ-imbalance and IQ-skew effects in multicarrier transmitters are presented. To compensate for such effects, a 4×4 MIMO widely linear adaptive equalizer is proposed and experimentally validated.......Simple analytical widely linear complex-valued models for IQ-imbalance and IQ-skew effects in multicarrier transmitters are presented. To compensate for such effects, a 4×4 MIMO widely linear adaptive equalizer is proposed and experimentally validated....

  9. The electrical properties of a strongly disordered system based on lightly doped germanium compensated by disordered regions

    International Nuclear Information System (INIS)

    Evseev, V.A.; Konopleva, R.F.; Yuferev, A.A.

    1976-01-01

    A study was made of lightly doped (Nsub(Sb) approximately 10 15 cm -3 ) n-Ge, heavily compensated (K = Nsub(A)/N sub(D) approximately 1) by fast neutrons from a reactor. Irradiation is shown to produce, near n-p conversion (annealing has the same effect near p-n conversion), a random relief of electrostatic potential which is caused by the overlap of the space-charge regions surrounding disordered regions (DR). the random potential field results in a spatial 'bending' of the whole band spectrum of germanium, similar to the way it is observed in amorphous semiconductors because of their disorder. Experiments show the conduction in the DR overlap region to be of an activated nature, associated with the ejection of carriers to the corresponding 'percolation' levels. The activation energy of such conduction varies with the degree of compensation. The shift of the Fermi level depends on the degree of compensation here in a much more sensitive way than in the case of compensation by chemical impurities. The properties of Ge obtained by DR overlap and by compensation with chemical impurities are compared. A superlinear I-V characteristic producing the switching effect is observed in strong electric fields (E approximately 10 3 V cm -1 ). A suggestion is made that a study of disordered systems, based on lightly doped germanium which is compensated with DRs produced by high-energy particles, should both help to obtain new information on the parameters of the DRs proper and help to simulate the properties of the amorphous semiconductors. (author)

  10. Radiometric compensation for cooperative distributed multi-projection system through 2-DOF distributed control.

    Science.gov (United States)

    Tsukamoto, Jun; Iwai, Daisuke; Kashima, Kenji

    2015-11-01

    This paper proposes a novel radiometric compensation technique for cooperative projection system based-on distributed optimization. To achieve high scalability and robustness, we assume cooperative projection environments such that 1. each projector does not have information about other projectors as well as target images, 2. the camera does not have information about the projectors either, while having the target images, and 3. only a broadcast communication from the camera to the projectors is allowed to suppress the data transfer bandwidth. To this end, we first investigate a distributed optimization based feedback mechanism that is suitable for the required decentralized information processing environment. Next, we show that this mechanism works well for still image projection, however not necessary for moving images due to the lack of dynamic responsiveness. To overcome this issue, we propose to implement an additional feedforward mechanism. Such a 2 Degree Of Freedom (2-DOF) control structure is well-known in control engineering community as a typical method to enhance not only disturbance rejection but also reference tracking capability, simultaneously. We theoretically guarantee and experimentally demonstrate that this 2-DOF structure yields the moving image projection accuracy that is overwhelming the best achievable performance only by the distributed optimization mechanisms.

  11. Temperature and humidity compensation in the determination of solvent vapors with a microsensor system.

    Science.gov (United States)

    Park, J; Zellers, E T

    2000-10-01

    Accounting for changes in temperature and ambient humidity is critical to the development of practical field vapor-monitoring instrumentation employing microfabricated sensor arrays. In this study, responses to six organic vapors were collected from two prototype field instruments over a range of ambient temperatures and relative humidities (RH). Each instrument contains an array of three unthermostated polymer-coated surface acoustic wave (SAW) resonators, a thermally desorbed adsorbent preconcentrator bed, a reversible pump and a small scrubber cartridge. Negligible changes in the vapor sensitivities with atmospheric RH were observed owing, in large part, to the temporal separation of co-adsorbed water from the organic vapor analytes upon thermal desorption of preconcentrated air samples. As a result, calibrations performed at one RH level could be used to determine vapors at any other RH without corrections using standard pattern recognition methods. Negative exponential temperature dependences that agreed reasonably well with those predicted from theory were observed for many of the vapor-sensor combinations. It was possible to select a subset of sensors with structurally diverse polymer coatings whose sensitivities to all six test vapors and selected binary vapor mixtures had similar temperature dependences. Thus, vapor recognition could be rendered independent of temperature and vapor quantification could be corrected for temperature with sufficient accuracy for most applications. The results indicate that active temperature control is not necessary and that temperature and RH compensation is achievable with a relatively simple microsensor system.

  12. The Prototype Inductive Adder With Droop Compensation for the CLIC Kicker Systems

    CERN Document Server

    Holma, J

    2014-01-01

    The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity and a nominal center-of-mass energy of 3 TeV. The CLIC predamping rings and damping rings (DRs) will produce, through synchrotron radiation, an ultralow emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02% (±2.5 V). An inductive adder is a very promising approach to meeting the specifications. Recently, a five-layer prototype has been built at CERN. Passive analog modulation has been applied to compensate the voltage droop, for example of the pulse capacitors. The output waveforms of the prototype inductive adder have been compared with predictions of the voltage droop and pulse shape. Conclusions are drawn concern...

  13. Novel Rx IQ mismatch compensation considering laser phase noise for CO-OFDM system

    Science.gov (United States)

    Ma, Xiurong; Ding, Zhaocai; Li, Kun; Wang, Xiao

    2015-08-01

    In this paper, a novel compensation scheme for receiver (Rx) in-phase/quadrature (IQ) mismatch is proposed in coherent optical orthogonal frequency division multiplexing (CO-OFDM) system in the presence of laser phase noise. In this scheme, laser phase noise and channel distortion were combined as a new channel transfer factor, the IQ mismatch factor and initial channel transfer factor can be estimated independently based on the relationship of IQ mismatch factors. And the channel transfer factor can be updated on a symbol-by-symbol basis which retrieves an estimation of the phase noise value by extracting and averaging the phase drift of all OFDM sub-channels. Numerical results indicate that when the phase and amplitude mismatch are 10° and 2 dB respectively, a 1.6 dB optical signal-to noise ratio is improved at laser linewidth of 60 kHz. Furthermore, the complexity of the proposed method is analyzed in terms of the number of required complex multiplications per bit.

  14. Mesothelioma incidence surveillance systems and claims for workers’ compensation. Epidemiological evidence and prospects for an integrated framework

    Science.gov (United States)

    2012-01-01

    Background Malignant mesothelioma is an aggressive and lethal tumour strongly associated with exposure to asbestos (mainly occupational). In Italy a large proportion of workers are protected from occupational diseases by public insurance and an epidemiological surveillance system for incident mesothelioma cases. Methods We set up an individual linkage between the Italian national mesothelioma register (ReNaM) and the Italian workers’ compensation authority (INAIL) archives. Logistic regression models were used to identify and test explanatory variables. Results We extracted 3270 mesothelioma cases with occupational origins from the ReNaM, matching them with 1625 subjects in INAIL (49.7%); 91.2% (1,482) of the claims received compensation. The risk of not seeking compensation is significantly higher for women and the elderly. Claims have increased significantly in recent years and there is a clear geographical gradient (northern and more developed regions having higher claims rates). The highest rates of compensation claims were after work known to involve asbestos. Conclusions Our data illustrate the importance of documentation and dissemination of all asbestos exposure modalities. Strategies focused on structural and systematic interaction between epidemiological surveillance and insurance systems are needed. PMID:22545679

  15. Mesothelioma incidence surveillance systems and claims for workers’ compensation. Epidemiological evidence and prospects for an integrated framework

    Directory of Open Access Journals (Sweden)

    Marinaccio Alessandro

    2012-07-01

    Full Text Available Abstract Background Malignant mesothelioma is an aggressive and lethal tumour strongly associated with exposure to asbestos (mainly occupational. In Italy a large proportion of workers are protected from occupational diseases by public insurance and an epidemiological surveillance system for incident mesothelioma cases. Methods We set up an individual linkage between the Italian national mesothelioma register (ReNaM and the Italian workers’ compensation authority (INAIL archives. Logistic regression models were used to identify and test explanatory variables. Results We extracted 3270 mesothelioma cases with occupational origins from the ReNaM, matching them with 1625 subjects in INAIL (49.7%; 91.2% (1,482 of the claims received compensation. The risk of not seeking compensation is significantly higher for women and the elderly. Claims have increased significantly in recent years and there is a clear geographical gradient (northern and more developed regions having higher claims rates. The highest rates of compensation claims were after work known to involve asbestos. Conclusions Our data illustrate the importance of documentation and dissemination of all asbestos exposure modalities. Strategies focused on structural and systematic interaction between epidemiological surveillance and insurance systems are needed.

  16. Rotation Modes Stability Analysis and Phase Compensation for Magnetically Suspended Flywheel Systems with Cross Feedback Controller and Time Delay

    Directory of Open Access Journals (Sweden)

    Yuan Ren

    2016-01-01

    Full Text Available This paper analyzes the effects of time delay on the stability of the rotation modes for the magnetically suspended flywheel (MSFW with strong gyroscopic effects. A multi-input multioutput system is converted into a single-input single-output control system with complex coefficient by variable reconstruction, and the stability equivalence of the systems before and after variable reconstruction is proven. For the rotation modes, the stability limits and corresponding vibration frequencies are found as a function of nondimensional magnetic stiffness and damping and nondimensional parameters of rotor speed and time delay. Additionally, the relationship between cross feedback control system stability and time delay is investigated. And an effective phase compensation method based on cross-channel is further presented. Simulation and experimental results are presented to demonstrate the correctness of the stability analysis method and the superiority of the phase compensation strategy.

  17. Nearshore Tests of the Tidal Compensation System for Point-Absorbing Wave Energy Converters

    Directory of Open Access Journals (Sweden)

    Valeria Castellucci

    2015-04-01

    Full Text Available The power production of the linear generator wave energy converter developed at Uppsala University is affected by variations of mean sea level. The reason is that these variations change the distance between the point absorber located on the surface and the linear generator located on the seabed. This shifts the average position of the translator with respect to the center of the stator, thereby reducing the generator output power. A device mounted on the point absorber that compensates for tides of small range by regulating the length of the connection line between the buoy at the surface and the linear generator has been constructed and tested. This paper describes the electro-mechanical, measurement, communication and control systems installed on the buoy and shows the results obtained before its connection to the generator. The adjustment of the line was achieved through a linear actuator, which shortens the line during low tides and vice versa. The motor that drives the mechanical device was activated remotely via SMS. The measurement system that was mounted on the buoy consisted of current and voltage sensors, accelerometers, strain gauges and inductive and laser sensors. The data collected were transferred via Internet to a Dropbox server. As described within the paper, after the calibration of the sensors, the buoy was assembled and tested in the waters of Lysekil harbor, a few kilometers from the Uppsala University research site. Moreover, the performance of the sensors, the motion of the mechanical device, the power consumption, the current control strategy and the communication system are discussed.

  18. Crosslinking of epoxy-polysiloxane system by reactive blending

    Czech Academy of Sciences Publication Activity Database

    Gonzales, M.; Kadlec, Petr; Štěpánek, Petr; Strachota, Adam; Matějka, Libor

    2004-01-01

    Roč. 45, č. 16 (2004), s. 5533-5541 ISSN 0032-3861 R&D Projects: GA AV ČR IAA4050008 Keywords : reactive blend ing * siloxane network * epoxy network Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.433, year: 2004

  19. Theoretical and numerical characterization of a 40 Gbps long-haul multi-channel transmission system with dispersion compensation

    Directory of Open Access Journals (Sweden)

    Kaikai Xu

    2015-08-01

    Full Text Available When updating the 10 Gbps optical transmission system to 40 Gbps, the main limits are chromatic dispersion, nonlinear effect, especially the interactions of dispersion and intra-channel nonlinearity. To optimize the performance of standard WDM in a 40 Gbps four-channel transmission system, numerical simulations are carried out to compare three different dispersion compensation techniques (without compensation; periodic dispersion compensation at the front end; and dispensation compensation all at the end of the system by means of highly dispersed pulses for chromatic dispersion on a terrestrial 40 Gbps system. Both the loss and dispersion of the transmission fiber are periodically compensated, since two dispersive elements are placed at the input and the output ends of a compensation period. Due to the interplay between dispersion, nonlinearity and signal power, and the effect of dispersion on the pulse evolution, the pulse compress can be optimized and the system performance can be improved to compare with the system with either pre- or post-dispersion compensation. On comparing pre- and post-compensation methods, it is found that the latter is superior to the former. Further performance optimization includes how to properly match the EDFA power and length of the fiber.

  20. Current developments and future perspective on technologies for system impairments and compensations

    Science.gov (United States)

    Weiershausen, Werner; Leppla, Ralph; Vorbeck, S.

    2002-07-01

    Due to increasing traffic demands telecommunication operators have to upgrade the transmission capacity of their networks. Since the success story of WDM in optical fiber based networks, component and system manufacturers as well as operators are dealing with the question if it is better to increase the number of WDM channels remaining at low channel bitrate or to enhance the channel line rate itself. The momentary situation is that already 10 Gbit/s based systems are installed for client traffic and are running properly. By a comparison of the technical advantages and business cases for a lot of transmission scenarios, the 10 Gbit/s solution turns out to be the preferable solution if compared to 2.5-Gbit/s-based systems. In the meantime 40GHz electronics has made severe progress so that now it seems to be possible to take the step towards the next hierarchy, the 40 Gbit/s channel rate. Nevertheless, many system manufacturers still wait with the market introduction of 40 Gbit/s, on the one hand because we observe a stagnant capacity demand this year, and on the other hand because the business case seems yet not to be competitive. One of the reasons for this is the impact of different physical limitations of fast optical fiber transmission. While the step from 2.5 to 10 Gbit/s still did not raise severe technological problems for medium distances, this is completely different for ultra long haul systems and especially for all 40-Gbit/s-based systems. While nonlinear effects still can be sufficiently managed, phenomena like, e.g., polarization-mode dispersion (PMD), chromatic dispersion mismatch, and gain tilt of optical amplifiers play an important role. Chromatic dispersion and polarization effects may vary with time so that either passive or adaptive compensation schemes may be needed in order to realize sufficiently long transmission distances. This paper will deal with different current solutions to overcome limitations from fibers and components, namely the use

  1. APPLICATION OF MODIFIED POWER FLOW TRACING METHOD FOR REACTIVE POWER PRICING IN PRACTICAL UTILITY SYSTEM

    Directory of Open Access Journals (Sweden)

    M. SUSITHRA

    2017-01-01

    Full Text Available Competitive trend towards restructuring and unbundling of transmission services has resulted in the need to discover the impact of a particular generator to load. This paper initially presents the analysis of three different reactive power valuation methods namely, Modified Ybus , Virtual flow approach and modified power flow tracing to compute the reactive power output from a particular generator to particular load. Among these methods, the modified power flow electricity tracing method is identified as the best method to trace the reactive power contribution from various reactive power sources to loads, transmission line, etc. Also this proposed method breakdown the total reactive power loss in a transmission line into components to be allocated to individual loads. Secondly, based on this Method a novel allocation method for reactive power service for practical system is proposed. Hence, this method can be useful in providing additional insight into power system operation and can be used to modify existing tariffs of charging for reactive power transmission loss and reactive power transmission services. Simulation and comparison results are shown by taking WSCC 9 and IEEE 30 bus system as test system.

  2. A Follow-up Study on Return to Work in the Year After Reporting an Occupational Injury Stratified by Outcome of the Workers' Compensation System

    DEFF Research Database (Denmark)

    Rudbeck, Marianne; Johansen, Jens Peter; Omland, Øyvind

    2018-01-01

    ) or slower (industrial accident) compared to claimants with recognized claim without compensation the subsequent year and at a faster rate after decision. CONCLUSIONS: Compensation claims and proceedings of the workers' compensation system probably increase time to return to work, other factors as health......OBJECTIVE: To compare return rates to work between different groups according to decision from the workers' compensation. METHOD: Register data on disability benefits were used to describe return rates to work in Kaplan-Meier curves and association with decision on compensation claims. Disability...... benefits were granted by the municipalities independently of any compensation claim if sick-listed. RESULTS: Claimants with ongoing claims were the group with the largest proportion remaining on disability benefits. Claimants with rejected claims returned to work at the same rate (occupational disease...

  3. Stress generation and hierarchical fracturing in reactive systems

    Science.gov (United States)

    Jamtveit, B.; Iyer, K.; Royne, A.; Malthe-Sorenssen, A.; Mathiesen, J.; Feder, J.

    2007-12-01

    Hierarchical fracture patterns are the result of a slowly driven fracturing process that successively divides the rocks into smaller domains. In quasi-2D systems, such fracture patterns are characterized by four sided domains, and T-junctions where new fractures stop at right angles to pre-existing fractures. We describe fracturing of mm to dm thick enstatite layers in a dunite matrix from the Leka ophiolite complex in Norway. The fracturing process is driven by expansion of the dunite matrix during serpentinization. The cumulative distributions of fracture lengths show a scaling behavior that lies between a log - normal and power law (fractal) distribution. This is consistent with a simple fragmentation model in which domains are divided according to a 'top hat' distribution of new fracture positions within unfractured domains. Reaction-assisted hierarchical fracturing is also likely to be responsible for other (3-D) structures commonly observed in serpentinized ultramafic rocks, including the mesh-textures observed in individual olivine grains, and the high abundance of rectangular domains at a wide range of scales. Spectacular examples of 3-D hierarchical fracture patterns also form during the weathering of basaltic intrusions (dolerites). Incipient chemical weathering of dolerites in the Karoo Basin in South Africa occurs around water- filled fractures, originally produced by thermal contraction or by externally imposed stresses. This chemical weathering causes local expansion of the rock matrix and generates elastic stresses. On a mm to cm scale, these stresses lead to mechanical layer-by-layer spalling, producing the characteristic spheroidal weathering patterns. However, our field observations and computer simulations demonstrate that in confined environments, the spalling process alone is unable to relieve the elastic stresses. In such cases, chemical weathering drives a much larger scale hierarchical fracturing process in which fresh dolerite undergoes a

  4. Analysis and compensation for the joint effects of HPA nonlinearity, I/Q imbalance and crosstalk in MIMO beamforming systems

    KAUST Repository

    Qi, Jian

    2011-03-01

    In this paper, we investigate the joint effects of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk, on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems, and propose a compensation method for the three impairments together. The performance of the MIMO TB system equipped with the proposed compensation scheme is evaluated in terms of average symbol error probability and capacity when transmissions are performed over uncorrelated Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, length of pilot symbols and phase-shift keying modulation order. © 2011 IEEE.

  5. Compensation of errors due to incident beam drift in a 3 DOF measurement system for linear guide motion.

    Science.gov (United States)

    Hu, Pengcheng; Mao, Shuai; Tan, Jiu-Bin

    2015-11-02

    A measurement system with three degrees of freedom (3 DOF) that compensates for errors caused by incident beam drift is proposed. The system's measurement model (i.e. its mathematical foundation) is analyzed, and a measurement module (i.e. the designed orientation measurement unit) is developed and adopted to measure simultaneously straightness errors and the incident beam direction; thus, the errors due to incident beam drift can be compensated. The experimental results show that the proposed system has a deviation of 1 μm in the range of 200 mm for distance measurements, and a deviation of 1.3 μm in the range of 2 mm for straightness error measurements.

  6. A Novel Adaptive H∞ Filtering Method with Delay Compensation for the Transfer Alignment of Strapdown Inertial Navigation Systems

    Directory of Open Access Journals (Sweden)

    Weiwei Lyu

    2017-11-01

    Full Text Available Transfer alignment is always a key technology in a strapdown inertial navigation system (SINS because of its rapidity and accuracy. In this paper a transfer alignment model is established, which contains the SINS error model and the measurement model. The time delay in the process of transfer alignment is analyzed, and an H∞ filtering method with delay compensation is presented. Then the H∞ filtering theory and the robust mechanism of H∞ filter are deduced and analyzed in detail. In order to improve the transfer alignment accuracy in SINS with time delay, an adaptive H∞ filtering method with delay compensation is proposed. Since the robustness factor plays an important role in the filtering process and has effect on the filtering accuracy, the adaptive H∞ filter with delay compensation can adjust the value of robustness factor adaptively according to the dynamic external environment. The vehicle transfer alignment experiment indicates that by using the adaptive H∞ filtering method with delay compensation, the transfer alignment accuracy and the pure inertial navigation accuracy can be dramatically improved, which demonstrates the superiority of the proposed filtering method.

  7. A Novel Adaptive H∞ Filtering Method with Delay Compensation for the Transfer Alignment of Strapdown Inertial Navigation Systems.

    Science.gov (United States)

    Lyu, Weiwei; Cheng, Xianghong

    2017-11-28

    Transfer alignment is always a key technology in a strapdown inertial navigation system (SINS) because of its rapidity and accuracy. In this paper a transfer alignment model is established, which contains the SINS error model and the measurement model. The time delay in the process of transfer alignment is analyzed, and an H∞ filtering method with delay compensation is presented. Then the H∞ filtering theory and the robust mechanism of H∞ filter are deduced and analyzed in detail. In order to improve the transfer alignment accuracy in SINS with time delay, an adaptive H∞ filtering method with delay compensation is proposed. Since the robustness factor plays an important role in the filtering process and has effect on the filtering accuracy, the adaptive H∞ filter with delay compensation can adjust the value of robustness factor adaptively according to the dynamic external environment. The vehicle transfer alignment experiment indicates that by using the adaptive H∞ filtering method with delay compensation, the transfer alignment accuracy and the pure inertial navigation accuracy can be dramatically improved, which demonstrates the superiority of the proposed filtering method.

  8. Phase error compensation for a 3-D shape measurement system based on the phase-shifting method

    Science.gov (United States)

    Zhang, Song; Huang, Peisen S.

    2005-11-01

    This paper describes a novel phase error compensation method for reducing the measurement error caused by non-sinusoidal waveforms in the phase-shifting method. For 3D shape measurement systems using commercial video projectors, the non-sinusoidal nature of the projected fringe patterns as a result of the nonlinear gamma curve of the projectors causes significant phase measurement error and therefore shape measurement error. The proposed phase error compensation method is based on our finding that the phase error due to the non-sinusoidal waveform of the fringe patterns depends only on the nonlinearity of the projector's gamma curve. Therefore, if the projector's gamma curve is calibrated and the phase error due to the nonlinearity of the gamma curve is calculated, a look-up-table (LUT) that stores the phase error can be constructed for error compensation. Our experimental results demonstrate that by using the proposed method, the measurement error can be reduced by 10 times. In addition to phase error compensation, a similar method is also proposed to correct the nonsinusoidality of the fringe patterns for the purpose of generating a more accurate flat image of the object for texture mapping. While not relevant to applications in metrology, texture mapping is important for applications in computer vision and computer graphics.

  9. Development of prediction models of stress and long-term disability among claimants to injury compensation systems: a cohort study.

    Science.gov (United States)

    Spittal, Matthew J; Grant, Genevieve; O'Donnell, Meaghan; McFarlane, Alexander C; Studdert, David M

    2018-04-28

    We sought to develop prognostic risk scores for compensation-related stress and long-term disability using markers collected within 3 months of a serious injury. Cohort study. Predictors were collected at baseline and at 3 months postinjury. Outcome data were collected at 72 months postinjury. Hospitalised patients with serious injuries recruited from four major trauma hospitals in Australia. 332 participants who made claims for compensation for their injuries to a transport accident scheme or a workers' compensation scheme. 12-item WHO Disability Assessment Schedule and 6 items from the Claims Experience Survey. Our model for long-term disability had four predictors (unemployed at the time of injury, history of a psychiatric disorder at time of injury, post-traumatic stress disorder symptom severity at 3 months and disability at 3 months). This model had good discrimination (R 2 =0.37) and calibration. The disability risk score had a score range of 0-180, and at a threshold of 80 had sensitivity of 56% and specificity of 86%. Our model for compensation-related stress had five predictors (intensive care unit admission, discharged to home, number of traumatic events prior to injury, depression at 3 months and not working at 3 months). This model also had good discrimination (area under the curve=0.83) and calibration. The compensation-related stress risk score had score range of 0-220 and at a threshold of 100 had sensitivity of 74% and specificity of 75%. By combining these two scoring systems, we were able to identify the subgroup of claimants at highest risk of experiencing both outcomes. The ability to identify at an early stage claimants at high risk of compensation-related stress and poor recovery is potentially valuable for claimants and the compensation agencies that serve them. The scoring systems we developed could be incorporated into the claims-handling processes to guide prevention-oriented interventions. © Article author(s) (or their employer

  10. Japan's compensation system for nuclear damage - As related to the TEPCO Fukushima Daiichi nuclear accidents

    International Nuclear Information System (INIS)

    Nomura, Toyohiro; Matsuura, Shigekazu; Takahashi, Yasufumi; Takenaka, Chihiro; Hokugo, Taro; Kamada, Toshihiko; Kamai, Hiroyuki

    2012-01-01

    Following the TEPCO Fukushima Daiichi nuclear power plant accident, extraordinary efforts were undertaken in Japan to implement a compensation scheme for the proper and efficient indemnification of the affected victims. This publication provides English translations of key Japanese legislative and administrative texts and other implementing guidance, as well as several commentaries by Japanese experts in the field of third party nuclear liability. The OECD Nuclear Energy Agency (NEA) has prepared this publication in co-operation with the government of Japan to share Japan's recent experience in implementing its nuclear liability and compensation regime. The material presented in the publication should provide valuable insights for those wishing to better understand the regime applied to compensate the victims of the accident and for those working on potential improvements in national regimes and the international framework for third party nuclear liability

  11. DNA repair in B. subtilis: an inducible dimer-specific W-reactivation system

    International Nuclear Information System (INIS)

    Fields, P.I.; Yasbin, R.E.

    1982-01-01

    The W-reactivation system of Bacillus subtilis can repair pyrimidine dimers in bacteriophage DNA. This inducible repair system can be activated by treatment of the bacteria with uv, alkylating agents, cross-linking agents and gamma irradiation. However, bacteriophage treated with agents other than those that cause pyrimidine dimers to be produced was not repaired by this unique form of W-reactivation. In contrast, the W-reactivation system of Escherichia coli can repair a variety of damages placed in the bacteriophage DNA

  12. Development of a computer-aided digital reactivity computer system for PWRs

    International Nuclear Information System (INIS)

    Chung, S.-K.; Sung, K.-Y.; Kim, D.; Cho, D.-Y.

    1993-01-01

    Reactor physics tests at initial startup and after reloading are performed to verify nuclear design and to ensure safety operation. Two kinds of reactivity computers, analog and digital, have been widely used in the pressurized water reactor (PWR) core physics test. The test data of both reactivity computers are displayed only on the strip chart recorder, and these data are managed by hand so that the accuracy of the test results depends on operator expertise and experiences. This paper describes the development of the computer-aided digital reactivity computer system (DRCS), which is enhanced by system management software and an improved system for the application of the PWR core physics test

  13. Luminescent systems based on the isolation of conjugated PI systems and edge charge compensation with polar molecules on a charged nanostructured surface

    Science.gov (United States)

    Ivanov, Ilia N.; Puretzky, Alexander A.; Zhao, Bin; Geohegan, David B.; Styers-Barnett, David J.; Hu, Hui

    2014-07-15

    A photoluminescent or electroluminescent system and method of making a non-luminescent nanostructured material into such a luminescent system is presented. The method of preparing the luminescent system, generally, comprises the steps of modifying the surface of a nanostructured material to create isolated regions to act as luminescent centers and to create a charge imbalance on the surface; applying more than one polar molecule to the charged surface of the nanostructured material; and orienting the polar molecules to compensate for the charge imbalance on the surface of the nanostructured material. The compensation of the surface charge imbalance by the polar molecules allows the isolated regions to exhibit luminescence.

  14. Development of a Temperature Compensation Method for the Radiation Detector of a Radiation Monitoring System

    International Nuclear Information System (INIS)

    Park, Ki Sun; Jeong, Jae Jun

    2014-01-01

    Americium, which has been used to date for the assessment of integrity and efficiency of the radiation detector, was replaced by an LED to resolve these problems. However, while americium is negligibly affected by the temperature and the surrounding environment, the LED is significantly affected by the temperature. Accordingly, a method to resolve this issue is needed. In this study, a temperature-compensated preamplifier was developed, where the reference luminous output of the LED affecting on temperatures is constantly maintained to be uniform by controlling the current and the PMT gain difference is compensated by controlling the high voltage from a comparison of the input and output pulse values. After setting up the experimental apparatus, the validity of the preamplifier was verified through radiation measurement experiments where the temperature was varied from 10 .deg. C to 60 .deg. C. The output signals of the scintillation detector of the RMS are intricately related to the temperature. In particular, the output signal value is greatly affected by the thermal equilibrium in the process of converting electro-magnetic energy to light energy and back to electrical energy. To compensate for these temperature characteristics, the americium standard source is used, since it is not affected by temperature, or a temperature compensation method using an LED optical-pulse as a reference value is used. In this study, instead of the americium standard source, an LED and a temperature detector were used to develop a temperature compensation device for the PMT amplification factor. To verify the validity of the developed method, a reference temperature of 25 .deg. C and a reference current of a 60μA LED optical-pulse were used to experimentally measure the radiation while varying the temperature from 10 .deg. C to 60 .deg. C using a Cs-137 standard source. The experiment results showed that the measurement error is reduced by approximately 83.3 % by using the

  15. Losses compensation; Compensation des pertes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One mission of RTE (Electric Power Transportation), is to watch over the losses compensation resulting from the power transport on the electric power network. Since january 2001, RTE makes good the electric losses by the purchase of energy. To choose the marketers, a consultation has been realized by RTE. This document presents the rules concerning these losses compensation. (A.L.B.)

  16. Design of the automatic landing inversion flight control system based on neural network compensation for UAV

    Science.gov (United States)

    Chen, Yinchao; Yang, Wei

    2009-12-01

    A dynamic inversion control method based on neural network compensation for UAV automatic landing is introduced. Aimed at the nonlinear characteristic of automatic landing procedure, the dynamic inversion method is used for feedback linearization. The on-line neural network is introduced to compensation dynamic inversion error caused by the disturbance factors during automatic landing and improves the controller performance. Numerical simulation presents that the control method can make the UAV follow the expected trace properly and have good dynamic performance and robust performance.

  17. RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS

    Directory of Open Access Journals (Sweden)

    Gabriel BURLACU,

    2011-11-01

    Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator

  18. Performance constraints and compensation for teleoperation with delay

    Science.gov (United States)

    Mclaughlin, J. S.; Staunton, B. D.

    1989-01-01

    A classical control perspective is used to characterize performance constraints and evaluate compensation techniques for teleoperation with delay. Use of control concepts such as open and closed loop performance, stability, and bandwidth yield insight to the delay problem. Teleoperator performance constraints are viewed as an open loop time delay lag and as a delay-induced closed loop bandwidth constraint. These constraints are illustrated with a simple analytical tracking example which is corroborated by a real time, 'man-in-the-loop' tracking experiment. The experiment also provides insight to those controller characteristics which are unique to a human operator. Predictive displays and feedforward commands are shown to provide open loop compensation for delay lag. Low pass filtering of telemetry or feedback signals is interpreted as closed loop compensation used to maintain a sufficiently low bandwidth for stability. A new closed loop compensation approach is proposed that uses a reactive (or force feedback) hand controller to restrict system bandwidth by impeding operator inputs.

  19. Harmonic currents Compensator Grid-Connected Inverter at the Microgrid

    DEFF Research Database (Denmark)

    Asuhaimi Mohd Zin, A.; Naderipour, A.; Habibuddin, M.H.

    2016-01-01

    The main challenge associated with the grid-connected inverter in distributed generation (DG) systems is to maintain the harmonic contents in output current below the specified values and compensates for unbalanced loads even when the grid is subject to disturbances such as harmonic distortion...... and unbalanced loads. To overcome these challenges, a current control strategy for a three-phase grid-connected inverter under unbalanced and nonlinear load conditions is presented. It enables grid-connected inverter by the proposed control method to inject balanced clean currents to the grid even when the local...... loads are unbalanced and/or nonlinear and also compensate of the harmonic currents and control the active and reactive power. The main advantage and objective of this method is to effectively compensate for the harmonic currents content of the grid current and microgrid without using any compensation...

  20. Comparative study of reference currents and DC bus voltage control for Three-Phase Four-Wire Four-Leg SAPF to compensate harmonics and reactive power with 3D SVM.

    Science.gov (United States)

    Chebabhi, A; Fellah, M K; Kessal, A; Benkhoris, M F

    2015-07-01

    In this paper the performances of three reference currents and DC bus voltage control techniques for Three-Phase Four-Wire Four-Leg SAPF are compared for balanced and unbalanced load conditions. The main goals are to minimize the harmonics, reduce the magnitude of neutral current, eliminate the zero-sequence current components caused by single-phase nonlinear loads and compensate the reactive power, and on the other hand improve performances such as robustness, stabilization, trajectory pursuit, and reduce time response. The three techniques are analyzed mathematically and simulation results are compared. The techniques considered for comparative study are the PI Control, Sliding Mode Control and the Backstepping Control. Synchronous reference frame theory (SRF) in the dqo-axes is used to generate the reference currents, of the inverter. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Linearization and Control of Series-Series Compensated Inductive Power Transfer System Based on Extended Describing Function Concept

    Directory of Open Access Journals (Sweden)

    Kunwar Aditya

    2016-11-01

    Full Text Available The extended describing function (EDF is a well-known method for modelling resonant converters due to its high accuracy. However, it requires complex mathematical formulation effort. This paper presents a simplified non-linear mathematical model of series-series (SS compensated inductive power transfer (IPT system, considering zero-voltage switching in the inverter. This simplified mathematical model permits the user to derive the small-signal model using the EDF method, with less computational effort, while maintaining the accuracy of an actual physical model. The derived model has been verified using a frequency sweep method in PLECS. The small-signal model has been used to design the voltage loop controller for a SS compensated IPT system. The designed controller was implemented on a 3.6 kW experimental setup, to test its robustness.

  2. Compensation for straightness measurement systematic errors in six degree-of-freedom motion error simultaneous measurement system.

    Science.gov (United States)

    Cui, Cunxing; Feng, Qibo; Zhang, Bin

    2015-04-10

    The straightness measurement systematic errors induced by error crosstalk, fabrication and installation deviation of optical element, measurement sensitivity variation, and the Abbe error in six degree-of-freedom simultaneous measurement system are analyzed in detail in this paper. Models for compensating these systematic errors were established and verified through a series of comparison experiments with the Automated Precision Inc. (API) 5D measurement system, and the experimental results showed that the maximum deviation in straightness error measurement could be reduced from 6.4 to 0.9 μm in the x-direction, and 8.8 to 0.8 μm in the y-direction, after the compensation.

  3. Coordinating a multi-retailer decentralized distribution system with random demand based on buyback and compensation contracts

    Directory of Open Access Journals (Sweden)

    Jinyu Ren

    2015-01-01

    Full Text Available Purpose: The purpose of this paper is to set up the coordinating mechanism for a decentralized distribution system consisting of a manufacturer and multiple independent retailers by means of contracts. It is in the two-stage supply chain system that all retailers sell an identical product made by the manufacturer and determine their order quantities which directly affect the expected profit of the supply chain with random demand. Design/methodology/approach: First comparison of the optimal order quantities in the centralized and decentralized system shows that the supply chain needs coordination. Then the coordination model is given based on buyback cost and compensation benefit. Finally the coordination mechanism is set up in which the manufacturer as the leader uses a buyback policy to incentive these retailers and the retailers pay profit returns to compensate the manufacturer. Findings: The results of a numerical example show that the perfect supply chain coordination and the flexible allocation of the profit can be achieved in the multi-retailer supply chain by the buyback and compensation contracts. Research limitations: The results based on assumptions might not completely hold in practice and the paper only focuses on studying a single product in two-stage supply chain. Practical implications: The coordination mechanism is applicable to a realistic supply chain under a private information setting and the research results is the foundation of further developing the coordination mechanism for a realistic multi-stage supply chain system with more products. Originality/value: This paper focused on studying the coordination mechanism for a decentralized multi-retailer supply chain by the joint application of the buyback and compensation contracts. Furthermore the perfect supply chain coordination and the flexible allocation of the profit are achieved.

  4. 76 FR 62 - Interpretive Standards for Systemic Compensation Discrimination and Voluntary Guidelines for Self...

    Science.gov (United States)

    2011-01-03

    ... to review comments will be provided with appropriate aids such as readers or print magnifiers. Copies... Standards prescribe procedures to be followed by OFCCP compliance officers when conducting investigations of... from OFCCP's traditional tailoring of compensation investigation and analytical procedures to the facts...

  5. Compensation of Complex Hysteresis and Creep Effects in Piezoelectrically Actuated Systems - A New Preisach Modeling Approach

    Czech Academy of Sciences Publication Activity Database

    Kuhnen, K.; Krejčí, Pavel

    2009-01-01

    Roč. 54, č. 3 (2009), s. 537-550 ISSN 0018-9286 Institutional research plan: CEZ:AV0Z10190503 Keywords : compensation * creep * hysteresis Subject RIV: BA - General Mathematics Impact factor: 2.556, year: 2009 http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4797784

  6. Reactivity changes in hybrid thermal-fast reactor systems during fast core flooding

    International Nuclear Information System (INIS)

    Pesic, M.

    1994-09-01

    A new space-dependent kinetic model in adiabatic approximation with local feedback reactivity parameters for reactivity determination in the coupled systems is proposed in this thesis. It is applied in the accident calculation of the 'HERBE' fast-thermal reactor system and compared to usual point kinetics model with core-averaged parameters. Advantages of the new model - more realistic picture of the reactor kinetics and dynamics during local large reactivity perturbation, under the same heat transfer conditions, are underlined. Calculated reactivity parameters of the new model are verified in the experiments performed at the 'HERBE' coupled core. The model has shown that the 'HERBE' safety system can shutdown reactor safely and fast even in the case of highly set power trip and even under conditions of big partial failure of the reactor safety system (author)

  7. An alternative approach to the management of reactive metals: tolerant cementitious systems

    International Nuclear Information System (INIS)

    Swift, P.; Cox, J.; Wise, M.; McKinney, J.; Rhodes, C.

    2015-01-01

    In recent years research has focused on preventing or minimising corrosion of reactive metals to ensure long-term waste package integrity. An alternative approach to the encapsulation of reactive metals is being explored. The approach will identify a cementitious-based encapsulating material that will allow corrosion of reactive metals to occur in a controlled and predictable manner, rather than seeking to limit or prevent the corrosion, whilst retaining waste package integrity. A low strength grout will be developed that will be 'tolerant' to the expansive forces generated by the corrosion products of reactive metals. Novel cementitious systems (e.g. foamed cements, rubber composite cements, cenosphere composite cements, lime mortars, bentonite cements etc.) that may be tolerant to potentially expansive waste products, such as reactive metals will be considered and assessed in a series of small-scale preliminary trials (compressive strength, porosity, permeability, pore solution pH, etc.)

  8. A temperature compensated fibre Bragg grating (FBG)-based sensor system for condition monitoring of electrified railway pantograph

    Science.gov (United States)

    Chen, Ye; Vidakovic, Miodrag; Fabian, Matthias; Swift, Martin; Brun, Lee; Sun, Tong; Grattan, Kenneth T. V.

    2017-04-01

    This paper presents the results obtained from fibre Bragg grating (FBG) sensors integrated into a railway current-collecting pantograph for accurate measurement of contact force and contact location when it is subjected to various temperature conditions. The temperature change of the pantograph is simulated, at the industrial laboratory of Brecknell Willis in the UK, by changing the DC current applied to pantograph from 0 to 1500 A. This test is primarily designed to verify the effectiveness of the temperature compensation mechanism built in the FBG sensor design. For this verification, 3 thermocouples co-located with the FBG sensor packages are used to measure the temperature change seen from 25 °C to 55 °C. The tests were repeated several times and the sensor system has shown its temperatureindependence, confirming that the intrinsic cross-sensitivity of FBGs to temperature variation for strain measurement has been fully compensated through the use of this innovative sensor design and data processing.

  9. 48 CFR 970.2270 - Unemployment compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unemployment compensation... Unemployment compensation. (a) Each state has its own unemployment compensation system to provide payments to... unemployment compensation benefits through a payroll tax on employers. Most DOE contractors are subject to the...

  10. A High Efficiency Charging Strategy for a Supercapacitor Using a Wireless Power Transfer System Based on Inductor/Capacitor/Capacitor (LCC Compensation Topology

    Directory of Open Access Journals (Sweden)

    Yuyu Geng

    2017-01-01

    Full Text Available In the application of rail transit vehicles, when using typical wireless power transfer (WPT systems with series–series (SS compensation supply power for supercapacitors, the output current is in an approximately inverse relationship with the duty cycle in a wide range. This renders the typical buck circuit control inappropriate. In order to help resolve the above issues, this paper designs inductor/capacitor/capacitor (LCC compensation with new compensation parameters, which can achieve an adjustable quasi-constant voltage from the input of the inverter to the output of the rectifier. In addition, the two-port network method is used to analyze the resonant compensation circuit. The analysis shows that LCC compensation is more suitable for the WPT system using the supercapacitor as the energy storage device. In the case of LCC compensation topology combined with the charging characteristics of the supercapacitor, an efficient charging strategy is designed, namely first constant current charging, followed by constant power charging. Based on the analysis of LCC compensation, the system has an optimal load, by which the system works at the maximum efficiency point. Combined with the characteristics of the constant voltage output, the system can maintain high efficiency in the constant power stage by making constant output power the same as the optimal power point. Finally, the above design is verified through experiments.

  11. Control of an Power Series Compensator in Distribution Systems Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    DEHINI Rachid

    2013-05-01

    Full Text Available Because of the bad effect exercised on electrical customers, the term “power quality” has gained significant attention. The main purpose ofSeries Active Power Filter (SAPF is to protect the sensitive loads from the voltage harmonics only, while Dynamic Voltage Restored (DVR can protect the consumer from supply voltage sag, voltage swell,voltage unbalance, and even voltage interruption. This paper is concerned with the novel active voltage compensator (AVC which can compensate all voltage disturbances. To identify voltage disturbances, many techniques are used, this work is an attempt to provide a AVC with identification method based on The Multilayer Feed Forward Neural Network (MLFFN. The simulation results during several cases confirmed that the AVC is able to eliminate all voltagedisturbances from utility grid.

  12. Analysis of an Electrochemical Blood Glucose Monitoring System with Hematocrit Compensation: Improved Accuracy by Design

    OpenAIRE

    Lyon, Martha E; Lyon, Andrew W

    2012-01-01

    The article entitled “Hematocrit Compensation in Electrochemical Blood Glucose Monitoring Systems” by Teodorczyk and colleagues in this issue of Journal of Diabetes Science and Technology demonstrates that the OneTouch® Verio™ glucose meter meets current regulatory expectations for glucose meter performance and is relatively free from interference by hematocrit. The lack of influence of hematocrit on whole blood glucose results is a valuable attribute for hospital applications, where greater ...

  13. Phase rule calculations and the thermodynamics of reactive systems under chemical equilibrium

    Directory of Open Access Journals (Sweden)

    PLATT G. M.

    1999-01-01

    Full Text Available In this paper, we examine the resolution of some phase rule problems within the context of multiple chemical equilibrium reactions, using cubic equations of state and an activity coefficient model. Bubble and dew reactive surfaces, reactive azeotropic loci and reactive critical loci are generated and presented in graphical form. Also isobaric bubble and dew reactive enthalpy loci, which may be useful in the modeling of reactive distillation operations, are depicted. All the formalism here employed is developed within the coordinate transformation of Ung and Doherty, which is appropriate for equilibrium reactive or multireactive systems. The major contribution of this work is the determination of critical loci for reactive or multireactive equilibrium systems. Since it is known that for some class of chemical reactions the kinetics and product distribution exhibit high sensitivity to pressure near criticality, the present study may be useful as a predicting tool in these cases if the chemical equilibrium condition is not too far from the real phenomenon.

  14. Force control compensation method with variable load stiffness and damping of the hydraulic drive unit force control system

    Science.gov (United States)

    Kong, Xiangdong; Ba, Kaixian; Yu, Bin; Cao, Yuan; Zhu, Qixin; Zhao, Hualong

    2016-05-01

    Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit (HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this

  15. A Tariff for Reactive Power

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would

  16. Compensability index for compensation radiotherapy after treatment interruptions

    Directory of Open Access Journals (Sweden)

    Putora Paul

    2012-12-01

    Full Text Available Abstract Background The goal of our work was to develop a simple method to evaluate a compensation treatment after unplanned treatment interruptions with respect to their tumour- and normal tissue effect. Methods We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions. In order to express and visualize the deviations from the originally planned tumour and normal tissue effects we defined the compensability index. Results The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect. An automated tool provides a method for quick evaluation of compensation treatments. Conclusions The compensability index calculation may serve as a decision support system based on existing and established recommendations.

  17. The Quadrennial Review of Military Compensation (3rd). Staff Studies and Selected Supporting Papers. Volume 9. Reserve Compensation, Sample Foreign Pay Systems

    Science.gov (United States)

    1976-12-01

    Commissioner allows remissions on taxation for members posted to Singapore, Malaysia, Papua and New Guinea to compensate for isolation, unpleasant...day of service. This is viewed by active duty personnel as inequitable. Some argue that the active duty quarters and subsistence allowances are also pay...fiscal year (See Tab E). Pays aid Allowances. Pay for ADT is on active military pay scales. This includes basic pay, subsistence allowances, subsistence

  18. Compensation of Actuator’s Saturation by Using Fuzzy Logic and Imperialist Competitive Algorithm in a System with PID Controller

    Directory of Open Access Journals (Sweden)

    Abbas Ali Zamani

    2012-07-01

    Full Text Available Physical systems always include constraints and limits. Usually, the limits and constraints, in the control systems, are appeared as temperature and pressure limits or pumps capacity. One of the existing limits in the systems with PID controller is associated with the actuator’s saturation limits. With the saturating of the actuator, the controller’s output and plant’s input will be different and the output signal of controller do not lead the system and their states could not update correctly where this issue makes the system response undesirable. In this paper, by adding a fuzzy compensator that it’s parameters are tuned using imperialist competitive algorithm, the actuator saturation is prevented and the important parameters of the system response, such as setting time and overshoot, are improved.

  19. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  20. A Method to Compensate for Display System Contrast Ratio Differences in Distributed Simulation

    Science.gov (United States)

    2009-07-01

    For each Producer program R,G,B color (range = 000 to 255) R + G + B = Total Color Units ( TCU ) If TCU < 1, then TCU = 1 R, G, B / TCU ...y (Cu – Cp)² = a (adjust factor) <This compensates for contrast ratio difference TCU - ((765 – TCU ) • a) = TCU2 <This changes intensity If TCU2...3.0 def c2, 0.001, 0, 0, 0 ; min TCU allowed ; declare registers dcl t0 dcl_2d s0 ; sample the input image texld r0, t0, s0 dp3 r1

  1. Static and quasi-static behavior of an adaptive system to compensate path errors for smart fiber placement

    Science.gov (United States)

    Perner, M.; Monner, H. P.; Krombholz, C.; Kruse, F. F.

    2015-04-01

    Smart fiber placement is an ambitious topic in current research for automated manufacturing of large-scale composite structures, e.g. wing covers. Adaptive systems get in focus to obtain a high degree of observability and controllability of the manufacturing process. In particular, vibrational issues and material failure have to be studied to significantly increase the production rate with no loss in accuracy of the fiber layup. As one contribution, an adaptive system has been developed to be integrated into the fiber placement head. It decouples the compaction roller from disturbances caused by misalignments, varying components' behavior over a large work area and acceleration changes during operation. Therefore, the smart system axially adapts the position of the compaction roller in case of disturbances. This paper investigates the behavior of the system to compensate quasi-static deviations from the desired path. In particular, the compensation efficiency of a constant offset, a linear drift with constant gradient and a single-curved drift is studied. Thus, the test bed with measurement devices and scenarios is explained. Based on the knowledge obtained by the experimental data, the paper concludes with a discussion of the proposed approach for its use under operating conditions and further implementation.

  2. A Teleo-Reactive Node for Implementing Internet of Things Systems.

    Science.gov (United States)

    Sánchez, Pedro; Álvarez, Bárbara; Antolinos, Elías; Fernández, Diego; Iborra, Andrés

    2018-04-01

    The Internet of Things (IoT) is one of today's main disruptive technologies and, although massive research has been carried out in recent years, there are still some open issues such as the consideration of software engineering methods and tools. We propose the adoption of the Teleo-Reactive approach in order to facilitate the development of Internet of Things systems as a set of communicating Teleo-Reactive nodes. The software behavior of the nodes is specified in terms of goals, perceptions and actions over the environment, achieving higher abstraction than using general-purpose programming languages and therefore, enhancing the involvement of non-technical users in the specification process. Throughout this paper, we describe the elements of a Teleo-Reactive node and a systematic procedure for translating Teleo-Reactive specifications into executable code for Internet of Things devices. The case study of a robotic agent is used in order to validate the whole approach.

  3. Fluence-compensated down-scattered neutron imaging using the neutron imaging system at the National Ignition Facility.

    Science.gov (United States)

    Casey, D T; Volegov, P L; Merrill, F E; Munro, D H; Grim, G P; Landen, O L; Spears, B K; Fittinghoff, D N; Field, J E; Smalyuk, V A

    2016-11-01

    The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

  4. Interior Point Method Evaluation for Reactive Power Flow Optimization in the Power System

    Directory of Open Access Journals (Sweden)

    Zbigniew Lubośny

    2013-03-01

    Full Text Available The paper verifies the performance of an interior point method in reactive power flow optimization in the power system. The study was conducted on a 28 node CIGRE system, using the interior point method optimization procedures implemented in Power Factory software.

  5. Stability analysis and compensation of network-induced delays in communication-based power system control: A survey.

    Science.gov (United States)

    Liu, Shichao; Liu, Peter Xiaoping; Wang, Xiaoyu

    2017-01-01

    This survey is to summarize and compare existing and recently emerging approaches for the analysis and compensation of the effects of network-induced delays on the stability and performance of communication-based power control systems. Several important communication-based power control systems are briefly introduced. The deterministic and stochastic methodologies of analyzing the impacts of network-induced delays on the stability of the communication-based power control systems are summarized and compared. A variety of control approaches are reviewed and compared for mitigating the effects of network-induced delays, depending on several design requirements, such as model dependence and design difficulty. The summary and comparison of these control approaches in this survey provide researchers and utilities valuable guidance for designing advanced communication-based power control systems in the future. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    .g. Germany and Italy. Those advanced features can be provided by next generation PV systems, and will be enhanced in the future to ensure an even efficient and reliable utilization of PV systems. In light of this, Reactive Power Injection (RPI) strategies for single-phase PV systems are explored...... like what the conventional power plants do today in the grid regulation participation. Requirements of ancillary services like Low-Voltage Ride-Through (LVRT) associated with reactive current injection and voltage support through reactive power control, have been in effectiveness in some countries, e...... in this paper. The RPI possibilities are: a) constant average active power control, b) constant active current control, c) constant peak current control and d) thermal optimized control strategy. All those strategies comply with the currently active grid codes, but are with different objectives. The proposed...

  7. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    . Those advanced features can be provided by next-generation PV systems, and will be enhanced in the future to ensure an even efficient and reliable utilization of PV systems. In the light of this, Reactive Power Injection (RPI) strategies for single-phase PV systems are explored in this paper. The RPI...... like what the conventional power plants do today in the grid regulation participation. Requirements of ancillary services like Low-Voltage Ride-Through (LVRT) associated with reactive current injection and voltage support through reactive power control, have been in effectiveness in some countries...... possibilities are: a) constant average active power control, b) constant active current control, c) constant peak current control and d) thermal optimized control strategy. All those strategies comply with the currently active grid codes, but are with different objectives. The thermal optimized control strategy...

  8. Guidelines for Distribution System Operators on Reactive Power Provision by Electric Vehicles in Low Voltage Grids

    DEFF Research Database (Denmark)

    Zecchino, Antonio; Marinelli, Mattia; Træholt, Chresten

    2017-01-01

    The increasing success of electric vehicles is bringing new technical challenges to power system operators. This work intends to provide guidelines for distribution system operators in terms of reactive power requirements when evaluating and authorizing electric vehicles supply equipment with fast...... charging capability in existing low voltage distribution feeders. The aim is to prevent the voltage to exceed the permitted values when charging at high power, by exploiting the effect of the reactive power. The proposed guidelines for distribution system operators are reported in a matrix, which indicates...... the amount of reactive power that an individual electric vehicle is expected to provide when connected to a low voltage feeder, in order to benefit of the desired voltage rise effect in comparison to the case of unitary power factor....

  9. Methodology for Design and Analysis of Reactive Distillation Involving Multielement Systems

    DEFF Research Database (Denmark)

    Jantharasuk, Amnart; Gani, Rafiqul; Górak, Andrzej

    2011-01-01

    A new methodology for design and analysis of reactive distillation has been developed. In this work, the elementbased approach, coupled with a driving force diagram, has been extended and applied to the design of a reactive distillation column involving multielement (multicomponent) systems....... The transformation of ordinary systems to element-based ones and the aggregation of non-key elements allow the important design parameters, such as the number of stages, feed stage and minimum reflux ratio, to be determined by using simple diagrams similar to those regularly employed for non-reactive systems...... consisting of two components. Based on this methodology, an optimal design configuration is identified using the equivalent binary-element-driving force diagram. Two case studies of methyl acetate (MeOAc) synthesis and methyl-tert-butyl ether (MTBE) synthesis have been considered to demonstrate...

  10. Towards Interactive Timing Analysis for Designing Reactive Systems

    Science.gov (United States)

    2014-04-03

    IBM and United Technologies), the Swedish Research Council (#623-2011- 955), and the Center for Hybrid and Embedded Software Systems ( CHESS ) at UC...623-2011-955), and the Center for Hybrid and Embedded Software Systems ( CHESS ) at UC Berkeley (supported by the National Science Foundation, NSF...analysis techniques have been designed for these kinds of predictable hardware platforms. For instance, Kim et al. [22] show how Scratchpad memory

  11. Is the variability of nickel patch test reactivity over time associated with fluctuations in the systemic T-cell reactivity to nickel?

    Science.gov (United States)

    Masjedi, K; Bruze, M; Hindsén, M; Minang, J; Ahlborg, N

    2009-07-01

    Patch test reactivity to nickel varies over time. To what extent this variation is associated with fluctuations in the T-cell reactivity to nickel is not known. Our aim was to investigate the relationship between variation over time in the patch test and the systemic T-cell reactivity to nickel. Patients (n = 15) with a history of contact allergy to nickel were subjected to three consecutive patch tests at 3-month intervals, utilizing NiSO4 at 10 concentrations ranging from 0.0032% to 12.5%. Prior to each patch test, blood mononuclear cells were analysed for T-cell reactivity to nickel by interleukin (IL)-4 and IL-13 enzyme-linked immunospot assay. Eleven patients reacted positively in all three patch tests, two patients reacted in one or two tests and two remained negative. All 13 positive patients displayed variability over time, in terms of the lowest dose of nickel to which they responded. Also the cytokine response to nickel varied over time but the patients' mean cytokine response was positively correlated with their mean patch test reactivity (r(s) = 0.70, P nickel displayed a similar pattern in many patients, there was no significant correlation between the individuals' variation over time in vivo and in vitro. The overall magnitude of the T-cell reactivity to nickel and the patch test reactivity are closely associated but fluctuations in the systemic T-cell reactivity cannot be singled out as the major cause of longitudinal variability in nickel patch test reactivity.

  12. Neutron density fluctuations in point reactor systems with dichotomic reactivity noise

    International Nuclear Information System (INIS)

    Sako, Okitsugu

    1984-01-01

    The exactly solvable stochastic point reactor model systems are analyzed through the stochastic Liouville equation. Three kinds of model systems are treated: (1) linear system without delayed neutrons, (2) linear system with one-group of delayed neutrons, and (3) nonlinear system with direct power feedback. The exact expressions for the fluctuations of neutron density, such as the moments, autocorrelation function and power spectral density, are derived in the case where the colored reactivity noise is described by the dichotomic, or two state, Markov process with arbitrary correlation time and intensity, and the effects of the finite correlation time and intensity of the noise on the neutron density fluctuations are investigated. The influence of presence of delayed neutrons and the effect of nonlinearity of system on the neutron density fluctuations are also elucidated. When the reactivity correlation time is very short, the correlation time has almost no effect on the power spectral density, and the relative fluctuation of neutron density in the stationary state is not affected very much by the presence of delayed neutrons and also by the nonlinearity of system. On the other hand, if the reactivity correlation time is very long, the effect of the reactivity noise on the power spectral density appears at very low frequency, and the presence of delayed neutrons has an effect of reducing the neutron density fluctuations. (author)

  13. Review of nuclear liability compensation systems applicable to reactors outside the United States

    International Nuclear Information System (INIS)

    McIntosh, C.

    1985-01-01

    The review, which summarizes the Paris Convention and the Brussels Supplementary Convention, as well as the laws of Canada, France, Federal Republic of Germany, Japan, Spain, Sweden, Switzerland, and the United Kingdom, notes that the Price-Anderson program has a number of common points with the laws of Western Europe. The points of similarly are the goal of ensuring simple and equitable compensation for victims without burdening the nuclear industry with an uneconomic load. Price-Anderson differs in the higher amounts fixed for nuclear operators' liability, although the limits are now closer together. The purpose of the comparisons is to help those concerned with US programs of third-party liability and indemnification with a broader perspective

  14. Active Head Motion Compensation of TMS Robotic System Using Neuro-Fuzzy Estimation

    Directory of Open Access Journals (Sweden)

    Wan Zakaria W.N.

    2016-01-01

    Full Text Available Transcranial Magnetic Stimulation (TMS allows neuroscientist to study human brain behaviour and also become an important technique for changing the activity of brain neurons and the functions they sub serve. However, conventional manual procedure and robotized TMS are currently unable to precisely position the TMS coil because of unconstrained subject’s head movement and excessive contact force between the coil and subject’s head. This paper addressed this challenge by proposing an adaptive neuro-fuzzy force control to enable low contact force with a moving target surface. A learning and adaption mechanism is included in the control scheme to improve position disturbance estimation. The results show the ability of the proposed force control scheme to compensate subject’s head motions while maintaining desired contact force, thus allowing for more accurate and repeatable TMS procedures.

  15. Genetic fuzzy system predicting contractile reactivity patterns of small arteries

    DEFF Research Database (Denmark)

    Tang, J; Sheykhzade, Majid; Clausen, B F

    2014-01-01

    information. We developed a genetic fuzzy system (GFS) algorithm that is capable of learning all information in time-domain physiological data. Data on isometric force development of isolated small arteries were used as a framework for developing and optimizing a GFS. GFS performance was improved by several......Monitoring of physiological surrogate end points in drug development generates dynamic time-domain data reflecting the state of the biological system. Conventional data analysis often reduces the information in these data by extracting specific data points, thereby discarding potentially useful...

  16. Requirements Engineering for Reactive Systems: Coloured Petri Nets for an Elevator Controller

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Fernandes, Joao Miguel; Tjell, Simon

    2007-01-01

    This paper presents a model-based approach to requirements engineering for reactive systems; we use an elevator controller as case study. We identify and justify two key properties that a model which we construct must have, namely: (1) controller-and-environment-partitioned, which means constitut......This paper presents a model-based approach to requirements engineering for reactive systems; we use an elevator controller as case study. We identify and justify two key properties that a model which we construct must have, namely: (1) controller-and-environment-partitioned, which means...

  17. An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

    Science.gov (United States)

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-05-13

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.

  18. Testing reactive systems with data: enumerative methods and constraint solving

    NARCIS (Netherlands)

    Calamé, Jens Rüdiger

    2008-01-01

    Software faults are a well-known phenomenon. In most cases, they are just annoying – if the computer game does not work as expected – or expensive – if once again a space project fails due to some faulty data conversion. In critical systems, however, faults can have life-threatening consequences. It

  19. Compensation of frequency selectivity and antenna effect for the energy detection Gaussian frequency-shift keying ultra-wideband system

    Directory of Open Access Journals (Sweden)

    Song Cui

    2016-03-01

    Full Text Available The energy detection (ED Gaussian frequency-shift keying (GFSK ultra-wideband (UWB system, transmits bit 0 and 1 using different-order derivatives of the Gaussian pulse. The spectra of the two pulses are separated entirely in the frequency domain, so it generates the orthogonality of these two pulses. This orthogonality in the frequency domain makes the GFSK system more robust in multipath channels and in the presence of synchronisation errors, so it shows a better bit error rate performance than the ED pulse-position modulation UWB system. However, the effect of frequency selectivity and antenna has not been discussed in earlier publications. In this study, the authors will analyse the effect of these two factors and propose a method to compensate the effect.

  20. ''Use of perturbative methods to break down the variation of reactivity between two systems''

    International Nuclear Information System (INIS)

    Perruchot-Triboulet, S.; Sanchez, R.

    1997-01-01

    The modification of the isotopic composition, the temperature or even accounting for across section uncertainties in one part of a nuclear reactor core, affects the value of the effective multiplication factor. A new tool allows the analysis of the reactivity effect generated by the modification of the system. With the help of the direct and adjoint fluxes, a detailed balance of reactivity, between the compared systems, is done for each isotopic cross section. After the presentation of the direct and adjoint transport equations in the context of the multigroup code transport APOLLO2, this note describes the method, based on perturbation theory, for the analysis of the reactivity variation. An example application is also given. (author)

  1. Investigation of the minimal reactive power support of generators

    International Nuclear Information System (INIS)

    Wu, H.; Yu, C.W.; Xu, N.; Ning, Y.; Chung, C.Y.

    2006-01-01

    Reactive power ancillary services or reactive power markets have attracted attention from researchers and system operators worldwide as a result of the emergence of competitive electricity power markets. Reactive power is an important system support service for the secure and reliable operation of power systems and its improper management can hinder the operational efficiency of other power markets. Reactive power of a generator has several roles, such as supplying reactive demand, maintaining system security and supporting its real power transmission. It is rational that the minimal reactive power used to support its real power transmission should not receive financial compensation in power markets and therefore, this component of reactive power can be regarded as the minimal reactive power support of a generator. This study used an optimal power flow (OPF) based method to quantitatively examine the basic components of a generator's reactive power. In order to illustrate this concept, a simple 5-bus system was used. The mathematical model and case study were presented and a theoretical analysis and explanations were provided. The operational constraints that influence the generator's minimal reactive power support were also discussed. It was concluded that the rationality of the model is valid and the existence of minimal reactive power support of generators was demonstrated through the study. 8 refs., 2 tabs., 1 fig

  2. Study for reactive power on distribution system line B RSG-GAS

    International Nuclear Information System (INIS)

    Yan Bony Marsahala

    2010-01-01

    Study for reactive power on distribution system line B RSG-GA is already done. The study intended to evaluate how much inductive load need the reactive power (positive), how much power factor, and what will be done to increase the power factor. The reactive power is the losses power, can't be changed into energy, but it is need for transmission process and it is cause the energy losses.The loads on distribution system line B consist of induction motors which are used for primary cooling system and secondary cooling system, lift, blower on cooling tower, and air condition system. Due to the motors using, the power factor are falling down to low. By the calculation results give that the inductive loads on distribution line Bare 850 KVA and these loads caused the low power factor 0.80. If we want to increase the power factor up to 0, 95, it is need to install the reactive loads likes capacitor bank 250 KVAR. (author)

  3. Obtaining additional energy savings from the Filumex project by means of the reactive power compensation; Obtencion de ahorros adicionales del proyecto Filumex mediante la compensacion de la potencia reactiva

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes Jaramillo, Enrique L.; Loredo Gutierrez, Miguel Angel; Hernandez Hernandez, Eduardo [Comision Federal de Electricidad, Mexico, D. F. (Mexico)

    1996-12-31

    This paper presents the proposal for establishing in a parallel way to Flamex project, the compensation in the intermediate tension network for the increment in reactive power supplied to the domestic user. This is due to the following three phenomena that occur in replacing incandescent light bulbs with fluorescent lamps: a) A fluorescent lamp has a power factor of 0.9; consequently it requires the supply of a reactive power of about 50% of its capacity. b) In replacing an incandescent light bulb for a fluorescent lamp, approximately 80% of its capacity is not supplied, this leads to the disappearance of a good deal of the user`s purely resistive load, that will cause that its natural power factor is decreased from 0.91 to 0.86 lagging. c) In decreasing the annual maximum demand in the distribution circuit in a greater proportion than the decrease of the annual consumption, their load factors and the annual losses will be increased and therefore the share of its annual energy losses will be increased in about 18.9%. The above, gives rise to the fact that the compensation of reactive power by means of the installation of capacitor banks in the main leads of the distribution circuit, turns out to be a highly appealing technical-economical solution, with a Benefit/Cost rate of 4, a return time of the investment of 2 years and a net benefit of $4.78/user (Pesos). [Espanol] Se presenta la propuesta para establecer en una forma paralela al proyecto FILUMEX, la compensacion en la red de media tension del incremento de la potencia reactiva suministrada al usuario domestico. Este es debido a los siguientes tres fenomenos que ocurren al sustituir los focos incandescentes por lamparas fluorescentes: a) Una lampara fluorescente tiene un factor de potencia de 0.9, por lo que requiere el suministro de una potencia reactiva de aproximadamente el 50% de su capacidad. b) Al sustituirse un foco incandescente por una lampara fluorescente, se deja de suministrar aproximadamente el 80

  4. Development of a novel information and communication technology system to compensate for a sudden shortage of emergency department physicians.

    Science.gov (United States)

    Tanaka, Kumiko; Nakada, Taka-Aki; Fukuma, Hiroshi; Nakao, Shota; Masunaga, Naohisa; Tomita, Keisuke; Matsumura, Yosuke; Mizushima, Yasuaki; Matsuoka, Tetsuya

    2017-01-23

    A sudden shortage of physician resources due to overwhelming patient needs can affect the quality of care in the emergency department (ED). Developing effective response strategies remains a challenging research area. We created a novel system using information and communication technology (ICT) to respond to a sudden shortage, and tested the system to determine whether it would compensate for a shortage. Patients (n = 4890) transferred to a level I trauma center in Japan during 2012-2015 were studied. We assessed whether the system secured the necessary physicians without using other means such as phone or pager, and calculated fulfillment rate by the system as a primary outcome variable. We tested for the difference in probability of multiple casualties among total casualties transferred to the ED as an indicator of ability to respond to excessive patient needs, in a secondary analysis before and after system introduction. The system was activated 24 times (stand-by request [n = 12], attendance request [n = 12]) in 24 months, and secured the necessary physicians without using other means; fulfillment rate was 100%. There was no significant difference in the probability of multiple casualties during daytime weekdays hours before and after system introduction, while the probability of multiple casualties during night or weekend hours after system introduction significantly increased compared to before system introduction (4.8% vs. 12.9%, P < 0.0001). On the whole, the probability of multiple casualties increased more than 2 times after system introduction 6.2% vs. 13.6%, P < 0.0001). After introducing the system, probability of multiple casualties increased. Thus the system may contribute to improvement in the ability to respond to sudden excessive patient needs in multiple causalities. A novel system using ICT successfully secured immediate responses from needed physicians outside the hospital without increasing user workload, and increased

  5. Comparison of digital signal-signal beat interference compensation techniques in direct-detection subcarrier modulation systems.

    Science.gov (United States)

    Li, Zhe; Erkilinc, M Sezer; Galdino, Lidia; Shi, Kai; Thomsen, Benn C; Bayvel, Polina; Killey, Robert I

    2016-12-12

    Single-polarization direct-detection transceivers may offer advantages compared to digital coherent technology for some metro, back-haul, access and inter-data center applications since they offer low-cost and complexity solutions. However, a direct-detection receiver introduces nonlinearity upon photo detection, since it is a square-law device, which results in signal distortion due to signal-signal beat interference (SSBI). Consequently, it is desirable to develop effective and low-cost SSBI compensation techniques to improve the performance of such transceivers. In this paper, we compare the performance of a number of recently proposed digital signal processing-based SSBI compensation schemes, including the use of single- and two-stage linearization filters, an iterative linearization filter and a SSBI estimation and cancellation technique. Their performance is assessed experimentally using a 7 × 25 Gb/s wavelength division multiplexed (WDM) single-sideband 16-QAM Nyquist-subcarrier modulation system operating at a net information spectral density of 2.3 (b/s)/Hz.

  6. Optimization Placement of Static Var Compensator (Svc) on Electrical Transmission System 150 kV Based on Smart Computation

    Science.gov (United States)

    Hasbullah; Mulyadi, Y.; Febriana, Y.; Abdullah, A. G.

    2018-02-01

    To improve voltage profile, we can use FACTS equipment. One of them is SVC (Static Var Compensator). This study aims to determine the location and optimal capacity of SVC and to determine the effect after SVC installation. This research was conducted in 150 kV transmission system, West Java load regulator area of South Bandung and New Ujungberung subsystem. The research method used for power flow simulation is Newton Raphson and to determine the optimal position and capacity of SVC was using genetic algorithm in MATLAB R2014. After the SVC placement is optimized, then the system performance will increase such as the voltage of all buses is at the standard level and the decrease of power losses.

  7. Elevation profile influence at key contractual performance parameters for LDS (Leak Detection Systems) based on compensated volume balance

    Energy Technology Data Exchange (ETDEWEB)

    Liebenberg, Lieb [TRANSNET Pipeline, Durban (South Africa); Bueno, David; Passos, Rafaela [KANOPUS Consulting, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper describes and discusses procedures and correlations to estimate performance parameters for Leak Detection Systems based on Compensation Volume Balance, at the portions not usually covered by international standards (like, API RP 1130). These parameters include: minimum acceptable leakage to be detected, under steady state conditions, based on flow measurement uncertainty, observed for both pipeline head and tail; an actual flow rate uncertainty against the one informed by the flow meter manufacturer documentation; the reference flow rate for steady state conditions; and the sensitivity one may expect for the system against a given probability of false alarms (i.e., the ways to correlate reliability, the main performance parameter as per API RP 1130 and sensitivity, the second one). A question usually not considered is: how the elevation profile may affect some of these parameters. That is the second main objective addressed herein, with actual examples employed in a South African multi product pipeline. (author)

  8. Assessing Reactive Strength Measures in Jumping and Hopping Using the Optojump™ System

    Directory of Open Access Journals (Sweden)

    Healy Robin

    2016-12-01

    Full Text Available The aim of this study was to assess the concurrent validity of the Optojump™ system (Microgate, Bolzano, Italy versus a force platform in the estimation of temporal and reactive strength measures. In two separate investigations, twenty physically active males performed double-leg and single-leg drop jumps from a box height of 0.3 m and a 10 s vertical bilateral hopping test. Contact time, flight time and total time (the sum of contact and flight time were concurrently assessed during single and double-leg drop jumps and during hopping. Jump height, the reactive strength index and the reactive strength ratio were also calculated from contact time and flight time. Despite intraclass correlation coefficients (ICCs for all variables being close to 1 (ICC > 0.975, a significant overestimation was found in contact time (0.005 ± 0.002 s and underestimations in flight time (0.005 ± 0.003 s, the reactive strength index (0.04 ± 0.02 m·s-1 and the reactive strength ratio (0.07 ± 0.04. Overestimations in contact time and underestimations in flight time were attributed to the physical design of the Optojump™ system as the transmitter and receiver units were positioned 0.003 m above the floor level. The Optojump™ demonstrated excellent overall temporal validity with no differences found between systems for total time. Coaches are advised to be consistent with the instrumentation used to assess athletes, however, in the case of comparison between reactive strength values collected with the Optojump™ and values collected with a force platform, regression equations are provided.

  9. Active and reactive power neurocontroller for grid-connected photovoltaic generation system

    Directory of Open Access Journals (Sweden)

    I. Abadlia

    2016-03-01

    Full Text Available Many researchers have contributed to the development of a firm foundation for analysis and design of control applications in grid-connected renewable energy sources. This paper presents an intelligent control algorithm fond on artificial neural networks for active and reactive power controller in grid-connected photovoltaic generation system. The system is devices into two parts in which each part contains an inverter with control algorithm. A DC/DC converter in output voltage established by control magnitude besides maximum power point tracker algorithm always finds optimal power of the PV array in use. A DC/AC hysteresis inverter designed can synchronize a sinusoidal current output with the grid voltage and accurate an independent active and reactive power control. Simulation results confirm the validation of the purpose. Neurocontroller based active and reactive power presents an efficiency control that guarantees good response to the steps changing in active and reactive power with an acceptable current/voltage synchronism. In this paper the power circuit and the control system of the presented grid-connected photovoltaic generation system is simulated and tested by MatLab/Simulink.

  10. The Hidden Cost of Untreated Paragangliomas of the Head and Neck: Systemic Reactive (AA Amyloidosis

    Directory of Open Access Journals (Sweden)

    Erkan Dervisoglu

    2015-01-01

    Full Text Available We report a case of a 51-year-old man who was diagnosed with systemic reactive (AA amyloidosis in association with untreated glomus jugulare and glomus caroticum tumors. He refused radiotherapy and renal replacement therapy. Paragangliomas, although rare, should be considered one of the tumors that can result in AA amyloidosis.

  11. Phosphorous adsorption and precipitation in a permeable reactive wall: Applications for wastewater disposal systems

    International Nuclear Information System (INIS)

    Baker, M.J.; Blowes, D.W.; Placek, C.J.

    1997-01-01

    A permeable reactive mixture has been developed using low cost, readily available materials that is capable of providing effective, long-term phosphorous treatment in areas impacted by on-land wastewater disposal. The reactive mixture creates a geochemical environment suitable for P-attenuation by both adsorption and precipitation reactions. Potential benefits include significant reductions in phosphorous loading to receiving groundwater and surface water systems, and the accumulation of P-mass in a finite and accessible volume of material. The mixture may be applied as a component within surface treatment systems or in subsurface applications such as horizontal or vertical permeable reactive walls. The mixture averaged > 90% treatment efficiency over 3.6 years of continuous-flow laboratory column experiments. The mixture was further evaluated at the pilot-scale to treat municipal wastewater, and the field-scale to treat a well-characterized septic system plume using an in situ funnel and gate system. Average PO 4 -P concentrations in effluent exiting the reactive mixture range between 0 - 0.3 mg/L. Mineralogical analyses have isolated the phases responsible for phosphorous uptake, and discrete phosphate precipitates have been identified

  12. Internally directed cognition and mindfulness: An integrative perspective derived from predictive and reactive control systems theory

    NARCIS (Netherlands)

    M. Tops (Mattie); M.A.S. Boksem (Maarten); M. Quirin (Markus); H. IJzerman (Hans); S.L. Koole (Sander)

    2014-01-01

    textabstractIn the present paper, we will apply the predictive and reactive control systems (PARCS) theory as a framework that integrates competing theories of neural substrates of awareness by describing the "default mode network" (DMN) and anterior insula (AI) as parts of two different behavioral

  13. Model-Based Requirements Analysis for Reactive Systems with UML Sequence Diagrams and Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon; Lassen, Kristian Bisgaard

    2008-01-01

    In this paper, we describe a formal foundation for a specialized approach to automatically checking traces against real-time requirements. The traces are obtained from simulation of Coloured Petri Net (CPN) models of reactive systems. The real-time requirements are expressed in terms of a derivat...

  14. Radioactive well logging system with shale (boron) compensation by gamma ray build-up

    International Nuclear Information System (INIS)

    Peelman, H.E.; Arnold, D.M.; Pitts, R.W. Jr.

    1976-01-01

    Earth formations in the vicinity of a well borehole are repetitively bombarded with bursts of high energy neutrons. A radiation detector in a sonde in the borehole senses the gamma rays induced by the capture of thermal neutrons and sends signals representative thereof to the surface. At the surface, two single channel energy analyzers, such as from 1.30 to 2.92 MeV and from 3.43 to 10.0 MeV, sense the formation thermal neutron capture gamma ray response after each neutron burst. The counts of thermal neutron capture gamma rays in these analyzers are used to distinguish between the presence of salt water and hydrocarbons, which is logged. By controlling the repetition rate of the neutron source, measured counting rates in formations with relatively large thermal neutron lifetimes are emphasized, compensating for borehole effects which could otherwise give rise to erroneous results in shale formations, which have a high boron content. 11 claims, 5 figures

  15. Loss Minimizing Operation of Doubly Fed Induction Generator Based Wind Generation Systems Considering Reactive Power Provision

    DEFF Research Database (Denmark)

    Baohua, Zhang; Hu, Weihao; Chen, Zhe

    2014-01-01

    The paper deals with control techniques for minimizing the operating loss of doubly fed induction generator based wind generation systems when providing reactive power. The proposed method achieves its goal through controlling the rotor side q-axis current in the synchronous reference frame....... The formula for the control reference is explicitly deduced in this paper considering the losses of the generator, the power electronic devices and the filter. Three control strategies are compared with the proposed method under different wind speeds and different reactive power references. The simulation...

  16. Voltage Stability Impact of Grid-Tied Photovoltaic Systems Utilizing Dynamic Reactive Power Control

    Science.gov (United States)

    Omole, Adedamola

    Photovoltaic (PV) DGs can be optimized to provide reactive power support to the grid, although this feature is currently rarely utilized as most DG systems are designed to operate with unity power factor and supply real power only to the grid. In this work, the voltage stability of a power system embedded with PV DG is examined in the context of the high reactive power requirement after a voltage sag or fault. A real-time dynamic multi-function power controller that enables renewable source PV DGs to provide the reactive power support necessary to maintain the voltage stability of the microgrid, and consequently, the wider power system is proposed. The loadability limit necessary to maintain the voltage stability of an interconnected microgrid is determined by using bifurcation analysis to test for the singularity of the network Jacobian and load differential equations with and without the contribution of the DG. The maximum and minimum real and reactive power support permissible from the DG is obtained from the loadability limit and used as the limiting factors in controlling the real and reactive power contribution from the PV source. The designed controller regulates the voltage output based on instantaneous power theory at the point-of-common coupling (PCC) while the reactive power supply is controlled by means of the power factor and reactive current droop method. The control method is implemented in a modified IEEE 13-bus test feeder system using PSCADRTM power system analysis software and is applied to the model of a Tampa ElectricRTM PV installation at Lowry Park Zoo in Tampa, FL. This dissertation accomplishes the systematic analysis of the voltage impact of a PV DG-embedded power distribution system. The method employed in this work bases the contribution of the PV resource on the voltage stability margins of the microgrid rather than the commonly used loss-of-load probability (LOLP) and effective load-carrying capability (ELCC) measures. The results of

  17. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System With Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2015-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators, and it is able to support certain amount of the reactive power. For a typical doubly fed induction generator (DFIG) wind turbine system, the reactive power can be supported either...... in a down-scaled DFIG system. It is concluded that overexcited reactive power injected from the grid-side converter has lower energy loss per year compared to the overexcited reactive power covered by the rotor-side converter. Furthermore, it is also found that the annual energy loss could even become lower...

  18. An EMTDC Model of a Three Level four MVAR Compensator

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg

    1997-01-01

    The paper discusses the dynamic characteristics of a three level ±4mvar solid state var compensator which is built and will be used for dynamic reactive power compensation in a wind farm. An investigation has been carried out of the influence of the compensator reactor, the DC intermediate voltag...

  19. Multi-rate cubature Kalman filter based data fusion method with residual compensation to adapt to sampling rate discrepancy in attitude measurement system.

    Science.gov (United States)

    Guo, Xiaoting; Sun, Changku; Wang, Peng

    2017-08-01

    This paper investigates the multi-rate inertial and vision data fusion problem in nonlinear attitude measurement systems, where the sampling rate of the inertial sensor is much faster than that of the vision sensor. To fully exploit the high frequency inertial data and obtain favorable fusion results, a multi-rate CKF (Cubature Kalman Filter) algorithm with estimated residual compensation is proposed in order to adapt to the problem of sampling rate discrepancy. During inter-sampling of slow observation data, observation noise can be regarded as infinite. The Kalman gain is unknown and approaches zero. The residual is also unknown. Therefore, the filter estimated state cannot be compensated. To obtain compensation at these moments, state error and residual formulas are modified when compared with the observation data available moments. Self-propagation equation of the state error is established to propagate the quantity from the moments with observation to the moments without observation. Besides, a multiplicative adjustment factor is introduced as Kalman gain, which acts on the residual. Then the filter estimated state can be compensated even when there are no visual observation data. The proposed method is tested and verified in a practical setup. Compared with multi-rate CKF without residual compensation and single-rate CKF, a significant improvement is obtained on attitude measurement by using the proposed multi-rate CKF with inter-sampling residual compensation. The experiment results with superior precision and reliability show the effectiveness of the proposed method.

  20. Teacher Compensation and Organization.

    Science.gov (United States)

    Kelley, Carolyn

    1997-01-01

    Examines changes in the conceptualization of schooling over time from an organizational perspective. Explores how compensation systems might be better designed to match alternative organizational designs, considering scientific management, effective schools, content-driven schooling, and high standards/high involvement schools as organizational…

  1. Dynamic compensation temperatures in a mixed spin-1 and spin-3/2 Ising system under a time-dependent oscillating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Mustafa, E-mail: keskin@erciyes.edu.t [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Kantar, Ersin [Institute of Science, Erciyes University, 38039 Kayseri (Turkey)

    2010-09-15

    We study the existence of dynamic compensation temperatures in the mixed spin-1 and spin-3/2 Ising ferrimagnetic system Hamiltonian with bilinear and crystal-field interactions in the presence of a time-dependent oscillating external magnetic field on a hexagonal lattice. We employ the Glauber transitions rates to construct the mean-field dynamic equations. We investigate the time dependence of an average sublattice magnetizations, the thermal behavior of the dynamic sublattice magnetizations and the total magnetization. From these studies, we find the phases in the system, and characterize the nature (continuous or discontinuous) of transitions as well as obtain the dynamic phase transition (DPT) points and the dynamic compensation temperatures. We also present dynamic phase diagrams, including the compensation temperatures, in the five different planes. A comparison is made with the results of the available mixed spin Ising systems.

  2. Dynamic compensation temperatures in a mixed spin-1 and spin-3/2 Ising system under a time-dependent oscillating magnetic field

    International Nuclear Information System (INIS)

    Keskin, Mustafa; Kantar, Ersin

    2010-01-01

    We study the existence of dynamic compensation temperatures in the mixed spin-1 and spin-3/2 Ising ferrimagnetic system Hamiltonian with bilinear and crystal-field interactions in the presence of a time-dependent oscillating external magnetic field on a hexagonal lattice. We employ the Glauber transitions rates to construct the mean-field dynamic equations. We investigate the time dependence of an average sublattice magnetizations, the thermal behavior of the dynamic sublattice magnetizations and the total magnetization. From these studies, we find the phases in the system, and characterize the nature (continuous or discontinuous) of transitions as well as obtain the dynamic phase transition (DPT) points and the dynamic compensation temperatures. We also present dynamic phase diagrams, including the compensation temperatures, in the five different planes. A comparison is made with the results of the available mixed spin Ising systems.

  3. Human Simulated Intelligent Control with Double-Direction Dead-Zone Compensation for Joint Motion Control of a Large-Sized Boom System

    Directory of Open Access Journals (Sweden)

    Rongsheng Liu

    2015-01-01

    Full Text Available Joint motion control of a 52-meter-long five-boom system driven by proportional hydraulic system is developed. It has been considered difficult due to strong nonlinearities and parametric uncertainties, the effect of which increases with the size of booms. A human simulated intelligent control scheme is developed to improve control performance by modifying control mode and control parameters. In addition, considering the negative effects caused by frequent and redundant reverse actions of the proportional valve, a double-direction compensation scheme is proposed to deal with the dead-zone nonlinearity of proportional valve. Sinusoidal motions are implemented on a real boom system. The results indicate that HSIC controller can improve control accuracy, and dead-zone nonlinearity is effectively compensated by proposed compensation scheme without introducing frequent reverse actions of proportional valve.

  4. MEMS Inertial Sensors-Based Multi-Loop Control Enhanced by Disturbance Observation and Compensation for Fast Steering Mirror System.

    Science.gov (United States)

    Deng, Chao; Mao, Yao; Ren, Ge

    2016-11-15

    In this paper, an approach to improve the disturbance suppression performance of a fast steering mirror (FSM) tracking control system based on a charge-coupled device (CCD) and micro-electro-mechanical system (MEMS) inertial sensors is proposed. The disturbance observation and compensation (DOC) control method is recommended to enhance the classical multi-loop feedback control (MFC) for line-of-sight (LOS) stabilization in the FSM system. MEMS accelerometers and gyroscopes have been used in the FSM system tentatively to implement MFC instead of fiber-optic gyroscopes (FOG) because of its smaller, lighter, cheaper features and gradually improved performance. However, the stabilization performance of FSM is still suffering a large number of mechanical resonances and time delay induced by a low CCD sampling rate, which causes insufficient error attenuation when suffering uncertain disturbances. Thus, in order to make further improvements on the stabilization performance, a cascaded MFC enhanced by DOC method is proposed. The sensitivity of this method shows the significant improvement of the conventional MFC system. Simultaneously, the analysis of stabilization accuracy is also presented. A series of comparative experimental results demonstrate the disturbance suppression performance of the FSM control system based on the MEMS inertial sensors can be effectively improved by the proposed approach.

  5. Comparison of Chromatic Dispersion Compensation Method Efficiency for 10 Gbit/S RZ-OOK and NRZ-OOK Wdm-Pon Transmission Systems

    Directory of Open Access Journals (Sweden)

    Alsevska A.

    2017-12-01

    Full Text Available In the paper, the authors compare efficiency of two physical dispersion compensation methods for single channel and 8-channel WDM fibre-optical transmission systems using return-to-zero (RZ and non-return-to-zero (NRZ line codes for operation within optical C-band frequencies by means of computer simulations. As one of the most important destructive effects in fibre optical transmission systems (FOTS is chromatic dispersion (CD, it is very important to reduce its negative effect on a transmitted signal. Dispersion compensation methods that were implemented in the research were dispersion compensating fibre (DCF and fibre Bragg grating (FBG. The main goal of the paper was to find out which dispersion compensation method (DCF or FBG provided the highest performance increase for fibre-optical transmission system and provided the longest transmission distance after dispersion compensation was implemented at different locations in the fibre-optical line while RZ or NRZ line codes were used. In the paper the reference point of signal quality for all measurements, which were obtained at the receiver, was BER<10−12.

  6. An Optimized Air-Core Coil Sensor with a Magnetic Flux Compensation Structure Suitable to the Helicopter TEM System.

    Science.gov (United States)

    Chen, Chen; Liu, Fei; Lin, Jun; Zhu, Kaiguang; Wang, Yanzhang

    2016-04-12

    The air-core coil sensor (ACS) is widely used as a transducer to measure the variation in magnetic fields of a helicopter transient electromagnetic (TEM) system. A high periodic emitting current induces the magnetic field signal of the underground medium. However, such current also generates a high primary field signal that can affect the received signal of the ACS and even damage the receiver. To increase the dynamic range of the received signal and to protect the receiver when emitting current rises/falls, the combination of ACS with magnetic flux compensation structure (bucking coil) is necessary. Moreover, the optimized ACS, which is composed of an air-core coil and a differential pre-amplifier circuit, must be investigated to meet the requirements of the helicopter TEM system suited to rapid surveying for shallow buried metal mine in rough topography. Accordingly, two ACSs are fabricated in this study, and their performance is verified and compared inside a magnetic shielding room. Using the designed ACSs, field experiments are conducted in Baoqing County. The field experimental data show that the primary field response can be compensated when the bucking coil is placed at an appropriate point in the range of allowed shift distance beyond the center of the transmitting coil and that the damage to the receiver induced by the over-statured signal can be solved. In conclusion, a more suitable ACS is adopted and is shown to have better performance, with a mass of 2.5 kg, resultant effective area of 11.6 m² (i.e., diameter of 0.496 m), 3 dB bandwidth of 66 kHz, signal-to-noise ratio of 4 (i.e., varying magnetic field strength of 0.2 nT/s), and normalized equivalent input noise of 3.62 nV/m².

  7. Nuclear engine flow reactivity shim control

    Science.gov (United States)

    Walsh, J.M.

    1973-12-11

    A nuclear engine control system is provided which automatically compensates for reactor reactivity uncertainties at the start of life and reactivity losses due to core corrosion during the reactor life in gas-cooled reactors. The coolant gas flow is varied automatically by means of specially provided control apparatus so that the reactor control drums maintain a predetermined steady state position throughout the reactor life. This permits the reactor to be designed for a constant drum position and results in a desirable, relatively flat temperature profile across the core. (Official Gazette)

  8. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System with Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators and it is able to support certain amount of the reactive power. For a typical doubly-fed induction generator wind turbine system, the reactive power can be supported either through...

  9. The chemical and mechanical behaviors of polymer / reactive metal systems under high strain rates

    Science.gov (United States)

    Shen, Yubin

    As one category of energetic materials, impact-initiated reactive materials are able to release a high amount of stored chemical energy under high strain rate impact loading, and are used extensively in civil and military applications. In general, polymers are introduced as binder materials to trap the reactive metal powders inside, and also act as an oxidizing agent for the metal ingredient. Since critical attention has been paid on the metal / metal reaction, only a few types of polymer / reactive metal interactions have been studied in the literature. With the higher requirement of materials resistant to different thermal and mechanical environments, the understanding and characterization of polymer / reactive metal interactions are in great demand. In this study, PTFE (Polytetrafluoroethylene) 7A / Ti (Titanium) composites were studied under high strain rates by utilizing the Taylor impact and SHPB tests. Taylor impact tests with different impact velocities, sample dimensions and sample configurations were conducted on the composite, equipped with a high-speed camera for tracking transient images during the sudden process. SHPB and Instron tests were carried out to obtain the stress vs. strain curves of the composite under a wide range of strain rates, the result of which were also utilized for fitting the constitutive relations of the composite based on the modified Johnson-Cook strength model. Thermal analyses by DTA tests under different flow rates accompanied with XRD identification were conducted to study the reaction mechanism between PTFE 7A and Ti when only heat was provided. Numerical simulations on Taylor impact tests and microstructural deformations were also performed to validate the constitutive model built for the composite system, and to investigate the possible reaction mechanism between two components. The results obtained from the high strain rate tests, thermal analyses and numerical simulations were combined to provide a systematic study on

  10. Reactivity Accidents in CAREM-25 Core with and Without Safety Systems Actuation

    International Nuclear Information System (INIS)

    Gimenez, Marcelo; Vertullo, Alicia; Schlamp, Miguel

    2000-01-01

    A reactivity accident in CAREM core can be provoked by different initiating events, a cold water injection in pressure vessel, a secondary side steam line breakage and a failure in the absorbing rods drive system.The present work analyses inadverted control rod withdraws transients.Maximum worth control rod (2.5 $) at normal velocity (1 cm/s) is adopted for the simulations (Reactivity ramp of 0.018 $/s).Different scenarios considering actuation of first shutdown system (FSS), second shutdown system (SSS) and selflimiting conditions were modeled.Results of the accident with actuation of FSS show that safety margins are well above critical values (DNBR and CPR).In the cases with failure of the FSS and success of SSS or selflimited, safety margins are below critical values, however, the SSS provides a reduction of elapsed time under advised margins

  11. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately...... estimate the active/reactive power values. The proposed control system enables the hybrid renewable energy generation system to be able to perform real-time grid interconnection services such as active voltage regulation, active power control, and fault ride-through.Simulation and experimental results...... demonstrate the superior performance of the proposed closed-loop control system....

  12. Theoretical and experimental research on machine tool servo system for ultra-precision position compensation on CNC lathe

    Science.gov (United States)

    Ma, Zhichao; Hu, Leilei; Zhao, Hongwei; Wu, Boda; Peng, Zhenxing; Zhou, Xiaoqin; Zhang, Hongguo; Zhu, Shuai; Xing, Lifeng; Hu, Huang

    2010-08-01

    The theories and techniques for improving machining accuracy via position control of diamond tool's tip and raising resolution of cutting depth on precise CNC lathes have been extremely focused on. A new piezo-driven ultra-precision machine tool servo system is designed and tested to improve manufacturing accuracy of workpiece. The mathematical model of machine tool servo system is established and the finite element analysis is carried out on parallel plate flexure hinges. The output position of diamond tool's tip driven by the machine tool servo system is tested via a contact capacitive displacement sensor. Proportional, integral, derivative (PID) feedback is also implemented to accommodate and compensate dynamical change owing cutting forces as well as the inherent non-linearity factors of the piezoelectric stack during cutting process. By closed loop feedback controlling strategy, the tracking error is limited to 0.8 μm. Experimental results have shown the proposed machine tool servo system could provide a tool positioning resolution of 12 nm, which is much accurate than the inherent CNC resolution magnitude. The stepped shaft of aluminum specimen with a step increment of cutting depth of 1 μm is tested, and the obtained contour illustrates the displacement command output from controller is accurately and real-time reflected on the machined part.

  13. Improving the Penetration of Wind Power with Dynamic Thermal Rating System, Static VAR Compensator and Multi-Objective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Jiashen Teh

    2018-04-01

    Full Text Available The integration of renewable energy sources, especially wind energy, has been on the rise throughout power systems worldwide. Due to this relatively new introduction, the integration of wind energy is often not optimized. Moreover, owing to the technical constraints and transmission congestions of the power network, most of the wind energy has to be curtailed. Due to various factors that influence the connectivity of wind energy, this paper proposes a well-organized posterior multi-objective (MO optimization algorithm for maximizing the connections of wind energy. In this regard, the dynamic thermal rating (DTR system and the static VAR compensator (SVC have been identified as effective tools for improving the loadability of the network. The propose MO algorithm in this paper aims to minimize: (1 wind energy curtailment, (2 operation cost of the network considering all investments and operations, also known as the total social cost, and (3 SVC operation cost. The proposed MO problem was solved using the non-dominated sorting genetic algorithm (NSGA II and it was tested on the modified IEEE reliability test system (IEEE-RTS. The results demonstrate the applicability of the proposed algorithm in aiding power system enhancement planning for integrating wind energy.

  14. IMPROVEMENT OF SYSTEM OF COMPENSATION OF NPR OF HIGHER EDUCATION INSTITUTION

    Directory of Open Access Journals (Sweden)

    Andrey E. Shklyaev

    2015-01-01

    Full Text Available The article is devoted to the problem of formation of effective system of remuneration of scientific and pedagogical staff of the University. The characteristic of different systems of remuneration of teachers of Russian higher educational institutions. Formulated some proposals for improving the effectiveness of the remuneration system of the NRP of the University. The suggested remuneration system makes it possible to relate the amount of salary of each individual teacher’s or employee’s performance with educational institutions in General and his personal labour contribution in particular.

  15. Influence of void effects on reactivity of coupled fast-thermal system HERBE

    International Nuclear Information System (INIS)

    Ljubenov, V.; Milovanovic, S.; Milovanovic, T.; Cuknic, O.

    1997-01-01

    Coupled fast-thermal system HERBE at the experimental zero power heavy water reactor RB is a system with the significant effects of the neutron leakage and neutron absorption. Presence of a coolant void introduces a new structure in an extremely heterogeneous core. In those conditions satisfactory results of the calculation are acquired only using specified space-energy homogenization procedure. In order to analyze transient appearances and accidental cases of the reactor systems, a procedure for modeling of influence of moderator and coolant loss on reactivity ('void effect') is developed. Reduction of the moderator volume fraction in some fuel channels due to air gaps or steam generation during the accidental moderator boiling, restricts validity of the diffusion approximation in the reactor calculations. In cases of high neutron flux gradients, which are consequence of high neutron absorption, application of diffusion approximation is questionable too. The problem may be solved using transport or Monte Carlo methods, but they are not acceptable in the routine applications. Applying new techniques based on space-energy core homogenization, such as the SPH method or the discontinuity factor method, diffusion calculations become acceptable. Calculations based on the described model show that loss of part of moderator medium introduce negative reactivity in the HERBE system. Calculated local void reactivity coefficients are used in safety analysis of hypothetical accidents

  16. Development of automated controller system for controlling reactivity by using FPGA in research reactor application

    International Nuclear Information System (INIS)

    Mohd Sabri Minhat; Izhar Abu Hussin; Mohd Idris Taib

    2012-01-01

    The scope for this research paper is to produce a detail design for Development of Automated Controller System for Controlling Reactivity by using FPGA in Research Reactor Application for high safety nuclear operation. The development of this project including design, purchasing, fabrication, installation, testing and validation and verification for one prototype automated controller system for controlling reactivity in industry local technology for human capacity and capability development towards the first Nuclear Power Programme (NPP) in Malaysia. The specific objectives of this research paper are to Development of Automated Controller System for Controlling Reactivity (ACSCR) in Research Reactor Application (PUSPATI TRIGA Reactor) by using simultaneous movement method; To design, fabricate and produce the accuracy of Control Rods Drive Mechanism to 0.1 mm resolution using a stepper motor as an actuator; To design, install and produce the system response to be more faster by using Field Programmable Gate Array (FPGA) and High Speed Computer; and to improve the Safety Level of the Research Reactor in high safety nuclear operation condition. (author)

  17. Reactive Safety

    Directory of Open Access Journals (Sweden)

    Rüdiger Ehlers

    2011-06-01

    Full Text Available The distinction between safety and liveness properties is a fundamental classification with immediate implications on the feasibility and complexity of various monitoring, model checking, and synthesis problems. In this paper, we revisit the notion of safety for reactive systems, i.e., for systems whose behavior is characterized by the interplay of uncontrolled environment inputs and controlled system outputs. We show that reactive safety is a strictly larger class of properties than standard safety. We provide algorithms for checking if a property, given as a temporal formula or as a word or tree automaton, is a reactive safety property and for translating such properties into safety automata. Based on this construction, the standard verification and synthesis algorithms for safety properties immediately extend to the larger class of reactive safety.

  18. Reactivity control system of a passively safe thorium breeder pebble bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wols, F.J., E-mail: f.j.wols@tudelft.nl; Kloosterman, J.L.; Lathouwers, D.; Hagen, T.H.J.J. van der

    2014-12-15

    Highlights: • A worth of over 15,000 pcm ensures achieving long-term cold shutdown in thorium PBR. • Control rod worth in side reflector is insufficient due to low-power breeder zone. • 20 control rods, just outside the driver zone, can achieve long-term cold shutdown. • BF{sub 3} gas can be inserted for reactor shutdown, but only in case of emergency. • Perturbation theory accurately predicts absorber gas worth for many concentrations. - Abstract: This work investigates the neutronic design of the reactivity control system for a 100 MW{sub th} passively safe thorium breeder pebble bed reactor (PBR), a conceptual design introduced previously by the authors. The thorium PBR consists of a central driver zone of 100 cm radius, surrounded by a breeder zone with 300 cm outer radius. The fissile content of the breeder zone is low, leading to low fluxes in the radial reflector region. Therefore, a significant decrease of the control rod worth at this position is anticipated. The reactivity worth of control rods in the side reflector and at alternative in-core positions is calculated using different techniques, being 2D neutron diffusion, perturbation theory and more accurate 3D Monte Carlo models. Sensitivity coefficients from perturbation theory provide a first indication of effective control rod positions, while the 2D diffusion models provide an upper limit on the reactivity worth achievable at a certain radial position due to the homogeneous spreading of the absorber material over the azimuthal domain. Three dimensional forward calculations, e.g. in KENO, are needed for an accurate calculation of the total control rod worth. The two dimensional homogeneous calculations indicate that the reactivity worth in the radial reflector is by far insufficient to achieve cold reactor shutdown, which requires a control rod worth of over 15 000 pcm. Three dimensional heterogeneous KENO calculations show that placing 20 control rods just outside the driver channel

  19. A Teleo-Reactive Node for Implementing Internet of Things Systems

    Directory of Open Access Journals (Sweden)

    Pedro Sánchez

    2018-04-01

    Full Text Available The Internet of Things (IoT is one of today’s main disruptive technologies and, although massive research has been carried out in recent years, there are still some open issues such as the consideration of software engineering methods and tools. We propose the adoption of the Teleo-Reactive approach in order to facilitate the development of Internet of Things systems as a set of communicating Teleo-Reactive nodes. The software behavior of the nodes is specified in terms of goals, perceptions and actions over the environment, achieving higher abstraction than using general-purpose programming languages and therefore, enhancing the involvement of non-technical users in the specification process. Throughout this paper, we describe the elements of a Teleo-Reactive node and a systematic procedure for translating Teleo-Reactive specifications into executable code for Internet of Things devices. The case study of a robotic agent is used in order to validate the whole approach.

  20. Recommendations for intelligent bridge monitoring systems: architecture and temperature-compensated bootstrap analysis

    Science.gov (United States)

    Lloyd, George M.; Wang, Ming L.; Wang, Xuan; Love, Joe

    2003-08-01

    A sizeable number of efforts have sought to instrument bridges for the purpose of structural monitoring and assessment. The outcomes of these efforts, as gaged by advances in the understanding of the definition of structural damage and their role in sensor selection as well as in the design of cost and data-effective monitoring systems, has itself been difficult to assess. The authors' experience with the design, construction, and operation of a monitoring system for the south-bound Kishwaukee Bridge has provided several lessons that bear upon these concerns. In this paper we describe certain aspects of the design of our Unix-based monitoring system. The system, patterned after similar systems developed for kick detection and well-control in the oil industry, has performed well in providing a continuous, low-cost monitoring platform for bridge engineers with immediately relevant information.

  1. Adaptive filter design based on the LMS algorithm for delay elimination in TCR/FC compensators.

    Science.gov (United States)

    Hooshmand, Rahmat Allah; Torabian Esfahani, Mahdi

    2011-04-01

    Thyristor controlled reactor with fixed capacitor (TCR/FC) compensators have the capability of compensating reactive power and improving power quality phenomena. Delay in the response of such compensators degrades their performance. In this paper, a new method based on adaptive filters (AF) is proposed in order to eliminate delay and increase the response of the TCR compensator. The algorithm designed for the adaptive filters is performed based on the least mean square (LMS) algorithm. In this design, instead of fixed capacitors, band-pass LC filters are used. To evaluate the filter, a TCR/FC compensator was used for nonlinear and time varying loads of electric arc furnaces (EAFs). These loads caused occurrence of power quality phenomena in the supplying system, such as voltage fluctuation and flicker, odd and even harmonics and unbalancing in voltage and current. The above design was implemented in a realistic system model of a steel complex. The simulation results show that applying the proposed control in the TCR/FC compensator efficiently eliminated delay in the response and improved the performance of the compensator in the power system. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  2. Compensation of Wave-Induced Motion and Force Phenomena for Ship-Based High Performance Robotic and Human Amplifying Systems

    Energy Technology Data Exchange (ETDEWEB)

    Love, LJL

    2003-09-24

    Learning Controller has little impact due to the variable nature of the wave period. We then introduce a new approach to HAT control, Ship Motion Compensation for Force Control Systems (SMCFCS). This basic approach uses inclinometer and acceleration information from the base of the robot to compensate for ship motion disturbances. Results of the simulation study show over an order of magnitude decrease in the disturbance force reflected back to the operator and an order of magnitude increase in positioning accuracy and resolution.

  3. A Coherent Optical OFDM Communication System with Nonlinear Distortion Compensation in the Channel and Receiver

    Science.gov (United States)

    Asha, R. S.; Jayasree, V. K.

    2017-08-01

    A simple and low-cost scheme is proposed for reducing the distortions in the coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system. The total wireless channel noise and the distortions in the receiver can be considered as an additive white Gaussian noise model and all distortions can be reduced using maximum likelihood sequence estimation (MLSE) equalizers. The performance of the CO-OFDM is analyzed for different fiber lengths and laser powers. Results show that the MLSE-equalized system can outperform with a higher Q-factor of 8 dB than conventional CO-OFDM system.

  4. Nonlinear Phase Noise Compensation in Experimental WDM Systems with 256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2017-01-01

    Nonlinear phase noise (NLPN) is studied in an experimental wavelength division multiplexed (WDM) system operating at 256QAM. Extremely narrow linewidth lasers (extracting the phase part of the nonlinear noise in a Raman amplified link. Based...

  5. Disjunctive Probabilistic Modal Logic is Enough for Bisimilarity on Reactive Probabilistic Systems

    OpenAIRE

    Bernardo, Marco; Miculan, Marino

    2016-01-01

    Larsen and Skou characterized probabilistic bisimilarity over reactive probabilistic systems with a logic including true, negation, conjunction, and a diamond modality decorated with a probabilistic lower bound. Later on, Desharnais, Edalat, and Panangaden showed that negation is not necessary to characterize the same equivalence. In this paper, we prove that the logical characterization holds also when conjunction is replaced by disjunction, with negation still being not necessary. To this e...

  6. MP98, an innovative reactivity control system for LWR and VHTR, tests results on prototypes

    International Nuclear Information System (INIS)

    Emin, M.; Gagne, J.F.

    2005-01-01

    MP98' Reactivity Control System is now a technology tested on a real scale prototypes. Demonstrator is working at PWR real conditions (155 bars, 320 degree C), and many accidents configurations could be simulated. This paper presents the technology, describes the demonstrator design and presents some results. Mock up and demonstrator have permitted to optimize the design of MP98' devices to prepare industrialization. (authors)

  7. The interactions of design, control and operability in reactive distillation systems

    DEFF Research Database (Denmark)

    Georgiadis, M.C.; Schenk, Myrian Andrea; Pistikopoulos, Stratos

    2002-01-01

    In this work the design and control of a reactive distillation column, described by a rigorous dynamic model, is tackled via two different optimization approaches. In the first, the steady-state process design and the control system are optimized sequentially. It is shown that operability...... is a strong function of the process design and potential operability bottlenecks are identified. In the second approach, the process design and the control system are optimized simultaneously leading to a more economically beneficial and better controlled system than that obtained using the sequential...

  8. A primary neuron culture system for the study of herpes simplex virus latency and reactivation.

    Science.gov (United States)

    Kobayashi, Mariko; Kim, Ju-Youn; Camarena, Vladimir; Roehm, Pamela C; Chao, Moses V; Wilson, Angus C; Mohr, Ian

    2012-04-02

    Herpes simplex virus type-1 (HSV-1) establishes a life-long latent infection in peripheral neurons. This latent reservoir is the source of recurrent reactivation events that ensure transmission and contribute to clinical disease. Current antivirals do not impact the latent reservoir and there are no vaccines. While the molecular details of lytic replication are well-characterized, mechanisms controlling latency in neurons remain elusive. Our present understanding of latency is derived from in vivo studies using small animal models, which have been indispensable for defining viral gene requirements and the role of immune responses. However, it is impossible to distinguish specific effects on the virus-neuron relationship from more general consequences of infection mediated by immune or non-neuronal support cells in live animals. In addition, animal experimentation is costly, time-consuming, and limited in terms of available options for manipulating host processes. To overcome these limitations, a neuron-only system is desperately needed that reproduces the in vivo characteristics of latency and reactivation but offers the benefits of tissue culture in terms of homogeneity and accessibility. Here we present an in vitro model utilizing cultured primary sympathetic neurons from rat superior cervical ganglia (SCG) (Figure 1) to study HSV-1 latency and reactivation that fits most if not all of the desired criteria. After eliminating non-neuronal cells, near-homogeneous TrkA(+) neuron cultures are infected with HSV-1 in the presence of acyclovir (ACV) to suppress lytic replication. Following ACV removal, non-productive HSV-1 infections that faithfully exhibit accepted hallmarks of latency are efficiently established. Notably, lytic mRNAs, proteins, and infectious virus become undetectable, even in the absence of selection, but latency-associated transcript (LAT) expression persists in neuronal nuclei. Viral genomes are maintained at an average copy number of 25 per neuron

  9. Reactive transport in a partially molten system with binary solid solution

    Science.gov (United States)

    Jordan, J.; Hesse, M. A.

    2017-12-01

    Melt extraction from the Earth's mantle through high-porosity channels is required to explain the composition of the oceanic crust. Feedbacks from reactive melt transport are thought to localize melt into a network of high-porosity channels. Recent studies invoke lithological heterogeneities in the Earth's mantle to seed the localization of partial melts. Therefore, it is necessary to understand the reaction fronts that form as melt flows across the lithological interface of a heterogeneity and the background mantle. Simplified melting models of such systems aide in the interpretation and formulation of larger scale mantle models. Motivated by the aforementioned facts, we present a chromatographic analysis of reactive melt transport across lithological boundaries, using theory for hyperbolic conservation laws. This is an extension of well-known linear trace element chromatography to the coupling of major elements and energy transport. Our analysis allows the prediction of the feedbacks that arise in reactive melt transport due to melting, freezing, dissolution and precipitation for frontal reactions. This study considers the simplified case of a rigid, partially molten porous medium with binary solid solution. As melt traverses a lithological contact-modeled as a Riemann problem-a rich set of features arise, including a reacted zone between an advancing reaction front and partial chemical preservation of the initial contact. Reactive instabilities observed in this study originate at the lithological interface rather than along a chemical gradient as in most studies of mantle dynamics. We present a regime diagram that predicts where reaction fronts become unstable, thereby allowing melt localization into high-porosity channels through reactive instabilities. After constructing the regime diagram, we test the one-dimensional hyperbolic theory against two-dimensional numerical experiments. The one-dimensional hyperbolic theory is sufficient for predicting the

  10. Flexible Compensation of Voltage and Current Unbalance and Harmonics in Microgrids

    Directory of Open Access Journals (Sweden)

    Seyyed Yousef Mousazadeh Mousavi

    2017-10-01

    Full Text Available In recent years, the harmonics and unbalance problems endanger the voltage and current quality of power systems, due to increasing usage of nonlinear and unbalanced loads. Use of Distributed Generation (DG-interfacing inverters is proposed for voltage or current compensation. In this paper, a flexible control method is proposed to compensate voltage and current unbalance and harmonics using the distributed generation (DG-interfacing inverters. This method is applicable to both grid-connected and islanded Microgrids (MGs. In the proposed method, not only the proper control of active and reactive powers can be achieved, but also there is flexibility in compensating the voltage or current quality problems at DG terminals or Points of Common Coupling (PCCs. This control strategy consists of active and reactive power controllers and a voltage/current quality-improvement block. The controller is designed in a stationary (αβ frame. An extensive simulation study has been performed and the results demonstrate the effectiveness of the proposed control scheme. Depending on the compensation modes, the harmonics and unbalance compensation of DG output current, MG-injected current to the grid, as well as PCC and DG voltages, can be achieved in grid-connected operation of MG while in the islanded operation, and the PCC and DG voltages compensation can be obtained through the proposed control scheme.

  11. Compressed sensing based joint-compensation of power amplifier's distortions in OFDMA cognitive radio systems

    KAUST Repository

    Ali, Anum Z.

    2013-12-01

    Linearization of user equipment power amplifiers driven by orthogonal frequency division multiplexing signals is addressed in this paper. Particular attention is paid to the power efficient operation of an orthogonal frequency division multiple access cognitive radio system and realization of such a system using compressed sensing. Specifically, precompensated overdriven amplifiers are employed at the mobile terminal. Over-driven amplifiers result in in-band distortions and out of band interference. Out of band interference mostly occupies the spectrum of inactive users, whereas the in-band distortions are mitigated using compressed sensing at the receiver. It is also shown that the performance of the proposed scheme can be further enhanced using multiple measurements of the distortion signal in single-input multi-output systems. Numerical results verify the ability of the proposed setup to improve error vector magnitude, bit error rate, outage capacity and mean squared error. © 2011 IEEE.

  12. Note: Three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water

    Science.gov (United States)

    Bhutta, M. Raheel; Hong, Keum-Shik; Kim, Beop-Min; Hong, Melissa Jiyoun; Kim, Yun-Hee; Lee, Se-Ho

    2014-02-01

    Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects.

  13. Real Time Compensation of the Load Torque for DC Drive System

    Directory of Open Access Journals (Sweden)

    Marian Gaiceanu

    2017-11-01

    Full Text Available The objective of this paper is to improve the control quality of the DC drive system based on Arduino platform. The nameplate DC motor data are useful to provide the DC motor parameters. The cascade control loops provides good dynamic performances for the DC drive system. By using an adequate electric generator, the DC motor is loaded appropriately. Compared to the conventional control methods, in order to improve the load torque disturbances, this paper introduces feedforward load control loop. The simulation and experimental results are shown in this paper.

  14. Low-complexity Joint Sub-carrier Phase Noise Compensation for Digital Multi-carrier Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Barletta, Luca; Zibar, Darko

    2017-01-01

    Joint sub-carrier phase noise processing is proposed which recovers the SNR penalty related to decreased sub-carrier baudrate w.r.t. single carrier systems. The method enables digital sub-banding to be safely employed for nonlinear mitigation for modulation formats of up to 256-QAM.......Joint sub-carrier phase noise processing is proposed which recovers the SNR penalty related to decreased sub-carrier baudrate w.r.t. single carrier systems. The method enables digital sub-banding to be safely employed for nonlinear mitigation for modulation formats of up to 256-QAM....

  15. Trends in VBA Disability Compensation Spending

    Science.gov (United States)

    2016-06-01

    Unemployability MCRMC Military Compensation and Retirement Modernization Commission PTSD Post -Traumatic Stress Disorder US United States VA...Defense Authorization Act of 2013 established the Military Compensation and Retirement Modernization Commission (MCRMC) to conduct a review of...military compensation and retirement systems and to make recommendations to modernize such programs. The Commission asked the Institute for Defense

  16. New Compensation Technique for Fiber Impairments in Ultra High Capacity Super channel Based on (QDPASK Dense wavelength division multiplex (DWDM systems

    Directory of Open Access Journals (Sweden)

    Ibrahim A.Murdas

    2017-07-01

    Full Text Available In this paper we want to increase the data rate and to get larger transmission distance, therefore we use the Advanced modulation technique QDPASK in DWDM system with low channels space. In case of long transmission distance and multi channels system both giving rise to inter channel crosstalk induced by fiber nonlinearities as a result the use of advanced modulation technique becomes difficult. In this paper Quaternary differential phase amplitude shift keying (QDPASK is designed for 32 dense wavelength division multiplexing (DWDM channels, therefore we proposed a new cascade compensation system consist of optical and digital back propagation techniques (ODBP for compensate the linear and nonlinear effects . A performance of the system was reported using QDPASK DWDM fiber-optic system for various system parameters. The research is tested in VPI maker environment.

  17. Nonlinear Impairment Compensation Using Expectation Maximization for PDM 16-QAM Systems

    DEFF Research Database (Denmark)

    Zibar, Darko; Winther, Ole; Franceschi, Niccolo

    2012-01-01

    We show experimentally that by using non-linear signal processing based algorithm, expectation maximization, nonlinear system tolerance can be increased by 2 dB. Expectation maximization is also effective in combating I/Q modulator nonlinearities and laser linewidth....

  18. Optimized design of resonant controller for stator current harmonic compensation in DFIG wind turbine systems

    DEFF Research Database (Denmark)

    Liu, Changjin; Chen, Wenjie; Blaabjerg, Frede

    2012-01-01

    This paper presents an analytical method to optimize the parameters of resonant controller which is used in a Doubly-Fed Induction Generator (DFIG). In the DFIG control system, the fundamental current loop is controlled by PI-controllers, and the stator harmonic current loop is controlled...

  19. Application of Load Compensation in Voltage Controllers of Large Generators in the Polish Power Grid

    Directory of Open Access Journals (Sweden)

    Bogdan Sobczak

    2014-03-01

    Full Text Available The Automatic Voltage Regulator normally controls the generator stator terminal voltage. Load compensation is used to control the voltage which is representative of the voltage at a point either within or external to the generator. In the Polish Power Grid (PPG compensation is ready to use in every AVR of a large generator, but it is utilized only in the case of generators operating at the same medium voltage buses. It is similar as in most European Power Grids. The compensator regulating the voltage at a point beyond the machine terminals has significant advantages in comparison to the slower secondary Voltage and Reactive Power Control System (ARNE1. The compensation stiffens the EHV grid, which leads to improved voltage quality in the distribution grid. This effect may be particularly important in the context of the dynamic development of wind and solar energy.

  20. Flexible Compensation of Voltage and Current Unbalance and Harmonics in Microgrids

    DEFF Research Database (Denmark)

    Mousazadeh, Seyyed Yousef; Jalilian, Alireza; Savaghebi, Mehdi

    2017-01-01

    In recent years, the harmonics and unbalance problem endanger the voltage and current quality of power systems due to increasing usage of nonlinear and unbalance loads. Using DG interfacing inverters is proposed for voltage or current compensation. In this paper, a flexible control method...... is proposed to compensate voltage and current unbalance and harmonics using the Distributed Generation (DG) interfacing inverters. This method is applicable to both grid-connected and islanded microgrids. In the proposed method, not only the proper control of active and reactive powers can be achieved......) frame. An extensive simulation study has been performed and the results demonstrate the effectiveness of the proposed control scheme. The results show that depending on the compensation mode, the harmonics and unbalance compensation of DGs’ output current, MG’s injected current to the grid as well...

  1. Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

    Science.gov (United States)

    Bragg-Sitton, Shannon M.; Hervol, David S.; Godfroy, Thomas J.

    2010-01-01

    A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, Ohio. This is a closed-cycle system that incorporates an electrically heated reactor core module, turboalternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

  2. A simple scoring system for breast MRI interpretation: does it compensate for reader experience?

    International Nuclear Information System (INIS)

    Marino, Maria Adele; Clauser, Paola; Woitek, Ramona; Wengert, Georg J.; Kapetas, Panagiotis; Bernathova, Maria; Pinker-Domenig, Katja; Helbich, Thomas H.; Baltzer, Pascal A.T.; Preidler, Klaus

    2016-01-01

    To investigate the impact of a scoring system (Tree) on inter-reader agreement and diagnostic performance in breast MRI reading. This IRB-approved, single-centre study included 100 patients with 121 consecutive histopathologically verified lesions (52 malignant, 68 benign). Four breast radiologists with different levels of MRI experience and blinded to histopathology retrospectively evaluated all examinations. Readers independently applied two methods to classify breast lesions: BI-RADS and Tree. BI-RADS provides a reporting lexicon that is empirically translated into likelihoods of malignancy; Tree is a scoring system that results in a diagnostic category. Readings were compared by ROC analysis and kappa statistics. Inter-reader agreement was substantial to almost perfect (kappa: 0.643-0.896) for Tree and moderate (kappa: 0.455-0.657) for BI-RADS. Diagnostic performance using Tree (AUC: 0.889-0.943) was similar to BI-RADS (AUC: 0.872-0.953). Less experienced radiologists achieved AUC: improvements up to 4.7 % using Tree (P-values: 0.042-0.698); an expert's performance did not change (P = 0.526). The least experienced reader improved in specificity using Tree (16 %, P = 0.001). No further sensitivity and specificity differences were found (P > 0.1). The Tree scoring system improves inter-reader agreement and achieves a diagnostic performance similar to that of BI-RADS. Less experienced radiologists, in particular, benefit from Tree. (orig.)

  3. Hydraulic performance evaluation of pressure compensating (pc) emitters and micro-tubing for drip irrigation system

    International Nuclear Information System (INIS)

    Mangrio, A.G.; Asif, M.; Jahangir, I.

    2013-01-01

    Drip irrigation system is necessary for those areas, where the water scarcity issues are present. The present study was conducted at the field station of Climate Change, Alternate Energy and Water Resources Institute (CAEWRI), National Agricultural Research Center (NARC), Islamabad, during 2013, regarding drip irrigation system. Drip irrigation system depends on uniform emitter application flow. All the emitters were tested and replicated thrice at pressure head (34 to 207Kpa) with an increment of 34 Kpa. The minimum and maximum discharges were 1.32 - 3.52, 3.36 - 5.42, and 43.22 - 100.99 Lph, with an average of 2.42, 4.63 and 73.66 Lph, for Bow Smith, RIS and Micro-tubing, respectively. It indicates that more than 90% of emission uniformity (EU) and uniformity coefficient (CU) for all Emitters, which shows excellent water application with least standard deviation, ranging 0.12 to 2.37, throughout the operating pressure heads in all emitters. An average coefficient of variation (CV) of all emitters were behaving less than 0.07, indicating an excellent class at all operating pressure heads between 34 to 207 Kpa. Moreover, the relationship of discharge and pressure of emitters indicates that discharge increased with the increase of pressure head. The Q-H curve plays key role in the selection of emitters. (author)

  4. Immune System Dysregulation, Viral Reactivation and Stress During Short-Duration Space Flight

    Science.gov (United States)

    Crucian, Brian; Mehta, Satish; Stowe, Raymond; Uchakin, Peter; Quiriarte, Heather; Pierson, Duane; Sams, Clarence

    2010-01-01

    This slide presentation reviews a study that was conducted to ascertain if the immune system dysregulation, viral reactivation and stress from short duration space flight were a result of the stress of landing and readjustment to gravity. The objectives of the study were to replace several recent immune studies with one comprehensive study that will include in-flight sampling; address lack of in-flight data: (i.e., determine the in-flight status of immunity, physiological stress, viral immunity/reactivation); determine the clinical risk related to immune dysregulation for exploration class spaceflight; and determine the appropriate monitoring strategy for spaceflight-associated immune dysfunction, that could be used for the evaluation of countermeasures.

  5. Preliminary investigation of actinide and xenon reactivity effects in accelerator transmutation of waste high-flux systems

    International Nuclear Information System (INIS)

    Olson, K.R.; Henderson, D.L.

    1995-01-01

    The possibility of an unstable positive reactivity growth in an accelerator transmutation of waste (ATW)-type high-flux system is investigated. While it has always been clear that xenon is an important actor in the reactivity response of a system to flux changes, it has been suggested that in very high thermal flux transuranic burning systems, a positive, unstable reactivity growth could be caused by the actinides alone. Initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately. The maximum change in reactivity after a flux change caused by the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or startup. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response caused by the actinides. The capabilities and applications of both the current actinide model and the xenon model are discussed. Finally, the need for a complete dynamic model for the high-flux fluid-fueled ATW system is addressed

  6. Advanced Reactive Power Reserve Management Scheme to Enhance LVRT Capability

    Directory of Open Access Journals (Sweden)

    Hwanik Lee

    2017-10-01

    Full Text Available Abstract: To increase the utilization of wind power in the power system, grid integration standards have been proposed for the stable integration of large-scale wind power plants. In particular, fault-ride-through capability, especially Low-Voltage-Ride-Through (LVRT, has been emphasized, as it is related to tripping in wind farms. Therefore, this paper proposes the Wind power plant applicable-Effective Reactive power Reserve (Wa-ERPR, which combines both wind power plants and conventional generators at the Point of Interconnection (POI. The reactive power capability of the doubly-fed induction generator wind farm was considered to compute the total Wa-ERPR at the POI with reactive power capability of existing generators. By using the Wa-ERPR management algorithm, in case of a violation of the LVRT standards, the amount of reactive power compensation is computed using the Wa-ERPR management scheme. The proposed scheme calculates the Wa-ERPR and computes the required reactive power, reflecting the change of the system topology pre- and post-contingency, to satisfy the LVRT criterion when LVRT regulation is not satisfied at the POI. The static synchronous compensator (STATCOM with the capacity corresponding to calculated amount of reactive power through the Wa-ERPR management scheme is applied to the POI. Therefore, it is confirmed that the wind power plant satisfies the LVRT criteria by securing the appropriate reactive power at the POI, by applying of the proposed algorithm.

  7. Accurate Compensation of Attitude Angle Error in a Dual-Axis Rotation Inertial Navigation System

    Directory of Open Access Journals (Sweden)

    Rui Jiang

    2017-03-01

    Full Text Available In the dual-axis rotation inertial navigation system (INS, besides the gyro error, accelerometer error, rolling misalignment angle error, and the gimbal angle error, the shaft swing angle and the axis non-orthogonal angle also affect the attitude accuracy. Through the analysis of the structure, we can see that the shaft swing angle and axis non-orthogonal angle will produce coning errors which cause the fluctuation of the attitude. According to the analysis of the rotation vector, it can be seen that the coning error will generate additional drift velocity along the rotating shaft, which can reduce the navigation precision of the system. In this paper, based on the establishment of the modulation average frame, the vector projection is carried out, and then the attitude conversion matrix and the attitude error matrix mainly including the shaft swing angle and axis non-orthogonal are obtained. Because the attitude angles are given under the static condition, the shaft swing angle and the axis non-orthogonal angle are estimated by the static Kalman filter (KF. This kind of KF method has been widely recognized as the standard optimal estimation tool for estimating the parameters such as coning angles (α1 , α2, initial phase angles (ϕ1,ϕ2, and the non-perpendicular angle (η. In order to carry out the system level verification, a dual axis rotation INS is designed. Through simulation and experiments, the results show that the amplitudes of the attitude angles’ variation are reduced by about 20%–30% when the shaft rotates. The attitude error equation is reasonably simplified and the calibration method is accurate enough. The attitude accuracy is further improved.

  8. Unit Commitment Taking into Account Reactive Power

    Science.gov (United States)

    Li, Xiangjun; Yamashiro, Susumu

    In this paper, a Voltage Magnitude Constrained OPF (VMC-OPF) algorithm to determine the reactive power injection from compensating equipment to load bus is developed. By introducing the proposed VMC-OPF to the real power related Unit Commitment (UC)(1), a novel daily UC method taking into account the reactive power to secure bus voltage magnitude is presented. The Transmission Access Charge (TAC) and Ancillary Services Charge (ASC) are included in the objective function for considering costs of using transmission network and supplying reactive power to maintain the voltage. Using the proposed UC, the difference between two schedules based on benefit maximization and cost minimization is also discussed. To demonstrate the effectiveness of the proposed UC method, we demonstrate various simulation results for a model power system of IEEE-118 bus system.

  9. Phase Noise Compensation for Nonlinearity-Tolerant Digital Subcarrier Systems With High-Order QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Barletta, L.; Zibar, Darko

    2017-01-01

    The fundamental penalty of sub-carrier modulation (SCM) with independent sub-carrier phase noise processing is estimated. It is shown that the fundamental signal-to-noise ratio (SNR) penalty related to poorer phase noise tolerance of decreased baudrate subcarriers increases significantly with modu...... carrier systems operating at the same net data-rate. The proposed algorithm enables high-order modulation formats with high count of sub-carriers to be safely employed for nonlinearity mitigation in optical communication systems......The fundamental penalty of sub-carrier modulation (SCM) with independent sub-carrier phase noise processing is estimated. It is shown that the fundamental signal-to-noise ratio (SNR) penalty related to poorer phase noise tolerance of decreased baudrate subcarriers increases significantly...... with modulation format size and can potentially exceed the gains of the nonlinear tolerance of SCM. A low complexity algorithm is proposed for joint sub-carrier phase noise processing, which is scalable in the number of sub-carriers and recovers almost entirely the fundamental SNR penalty with respect to single...

  10. Injection Bucket Jitter Compensation Using Phase Lock System at Fermilab Booster

    Energy Technology Data Exchange (ETDEWEB)

    Seiya, K. [Fermilab; Drennan, C. [Fermilab; Pellico, W. [Fermilab; Chaurize, S. [Fermilab

    2017-05-12

    The extraction bucket position in the Fermilab Booster is controlled with a cogging process that involves the comparison of the Booster rf count and the Recycler Ring revolution marker. A one rf bucket jitter in the ex-traction bucket position results from the variability of the process that phase matches the Booster to the Recycler. However, the new slow phase lock process used to lock the frequency and phase of the Booster rf to the Recycler rf has been made digital and programmable and has been modified to correct the extraction notch position. The beam loss at the Recycler injection has been reduced by 20%. Beam studies and the phase lock system will be discussed in this paper.

  11. Differential Autonomic Nervous System Reactivity in Depression and Anxiety During Stress Depending on Type of Stressor.

    Science.gov (United States)

    Hu, Mandy X; Lamers, Femke; de Geus, Eco J C; Penninx, Brenda W J H

    2016-06-01

    It remains unclear whether depressive and anxiety disorders are associated with hyporeactivity or hyperreactivity of the autonomic nervous system (ANS) and whether deviant reactivity occurs in all types of stressors. This study compared ANS reactivity in people with current or remitted depression/anxiety with reactivity in healthy controls during two stress conditions. From the Netherlands Study of Depression and Anxiety, data of 804 individuals with current depression/anxiety, 913 individuals with remitted depression/anxiety, and 466 healthy controls (mean age = 44.1 years; 66.4% female) were available. Two conditions were used to evoke stress: a) an n-back task, a cognitively challenging stressor, and 2) a psychiatric interview, evoking personal-emotional stress related to the occurrence of symptoms of depression/anxiety. Indicators of ANS activity were heart rate (HR), root mean square of differences between successive interbeat intervals (RMSSD), respiratory sinus arrhythmia (RSA), and preejection period. As compared with controls, participants with psychopathology had significant hyporeactivity of HR (controls = 4.1 ± 4.2 beats/min; remitted = 3.5 ± 3.5 beats/min; current psychopathology = 3.1 ± 3.4 beats/min), RMSSD (controls = -6.2 ± 14.5 milliseconds; remitted = -5.4 ± 17.8 milliseconds; current psychopathology = -3.5 ± 15.4 milliseconds), and RSA (controls = -9.3 ± 17.0 milliseconds; remitted = -7.4 ± 16.5 milliseconds; current psychopathology = -6.9 ± 15.0 milliseconds) during the n-back task. In contrast, during the psychiatric interview, they showed significant hyperreactivity of HR (controls = 2.7 ± 3.4 beats/min; remitted = 3.5 ± 3.4 beats/min; current psychopathology = 4.0 ± 3.3 beats/min), RMSSD (controls = -3.4 ± 12.2 milliseconds; remitted = -4.1 ± 12.1 milliseconds; current psychopathology = -5.6 ± 11.8 milliseconds), and RSA (controls = -3.8 ± 8.1 milliseconds; remitted = -4.3 ± 7.9 milliseconds; current psychopathology = -5.0

  12. A compensation method to improve the performance of IPI-based entity recognition system in body sensor networks.

    Science.gov (United States)

    Bao, Shu-Di; He, Zhong-Kun; Jin, Rong; An, Peng

    2013-01-01

    Security of wireless body sensor networks (BSNs) with telemedicine applications remains a crucial issue. A family of novel biometrics schemes has been recently proposed for node recognition and cryptographic key distribution without any pre-deployment in BSNs, where dynamic entity identifiers (EIs) generated from physiological signals captured by individual sensor nodes are used for nodes to recognize each other. As the recognition performance of EIs determines the maximal performance that can be achieved in such biometric systems, several kinds of EI generation schemes have been proposed. The inter-pulse intervals based EI generation scheme is more promising for such applications in actual scenarios because of its acceptable recognition performance. However, it was found that such generated EIs by true pairs of nodes, i.e. two nodes from the same BSN, have some error pattern which could be considered while doing node recognition or key distribution for an improved success rate. To address the problem, this work proposes an error-correcting code based compensation method which can be easily combined together with the key distribution process to achieve an improved recognition performance. Results of statistical analysis with experimental data collected from 14 subjects show that the bit difference between EIs from true pairs of nodes can be effectively reduced with the proposed method.

  13. Analysis of Fade Detection and Compensation Experimental Results in a Ka-Band Satellite System. Degree awarded by Akron Univ., May 2000

    Science.gov (United States)

    Johnson, Sandra

    2001-01-01

    The frequency bands being used for new satellite communication systems are constantly increasing to accommodate the requirements for additional capacity. At these higher frequencies, propagation impairments that did not significantly affect the signal at lower frequencies begin to have considerable impact. In Ka-band, the next logical commercial frequency band to be used for satellite communication, attenuation of the signal due to rain is a primary concern. An experimental satellite built by NASA, the Advanced Communication Technology Satellite (ACTS), launched in September 1993, is the first US communication satellite operating in the Ka-band. In addition to higher carrier frequencies, a number of other new technologies, including onboard baseband processing, multiple beam antennas, and rain fade detection and compensation techniques, were designed into the ACTS. Verification experiments have been conducted since the launch to characterize the new technologies. The focus of this thesis is to describe and validate the method used by the ACTS Very Small Aperture Terminal (VSAT) ground stations in detecting the presence of fade in the communication signal and to adaptively compensate for it by the addition of burst rate reduction and forward error correction. Measured data obtained from the ACTS program is used to validate the compensation technique. In this thesis, models in MATLAB are developed to statistically characterize the increased availability achieved by the compensation techniques in terms of the bit error rate time enhancement factor. Several improvements to the ACTS technique are discussed and possible implementations for future Ka-band systems are also presented.

  14. Accuracy of tumor motion compensation algorithm from a robotic respiratory tracking system: A simulation study

    International Nuclear Information System (INIS)

    Seppenwoolde, Yvette; Berbeco, Ross I.; Nishioka, Seiko; Shirato, Hiroki; Heijmen, Ben

    2007-01-01

    The Synchrony TM Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model (linear or polynomial) between internal tumor motion and external (chest/abdominal) marker motion. The radiation beam follows the tumor movement via the continuously measured external marker motion. To establish the correspondence model at the start of treatment, the 3D internal tumor position is determined at 15 discrete time points by automatic detection of implanted gold fiducials in two orthogonal x-ray images; simultaneously, the positions of the external markers are measured. During the treatment, the relationship between internal and external marker positions is continuously accounted for and is regularly checked and updated. Here we use computer simulations based on continuously and simultaneously recorded internal and external marker positions to investigate the effectiveness of tumor tracking by the RTS. The Cyberknife does not allow continuous acquisition of x-ray images to follow the moving internal markers (typical imaging frequency is once per minute). Therefore, for the simulations, we have used data for eight lung cancer patients treated with respiratory gating. All of these patients had simultaneous and continuous recordings of both internal tumor motion and external abdominal motion. The available continuous relationship between internal and external markers for these patients allowed investigation of the consequences of the lower acquisition frequency of the RTS. With the use of the RTS, simulated treatment errors due to breathing motion were reduced largely and consistently over treatment time for all studied patients. A considerable part of the maximum reduction in treatment error could

  15. Microparticles from patients with systemic lupus erythematosus induce production of reactive oxygen species and degranulation of polymorphonuclear leukocytes

    DEFF Research Database (Denmark)

    Winberg, Line Kjær; Jacobsen, Søren; Nielsen, Claus H

    2017-01-01

    BACKGROUND: The interaction of circulating microparticles (MPs) with immune cells in systemic lupus erythematosus (SLE) is sparsely investigated. We examined the ability of MPs from SLE patients to induce production of reactive oxygen species (ROS) and degranulation of polymorphonuclear leukocytes...

  16. Inverted Unified Power Quality Conditioner to compensate overvoltage

    Directory of Open Access Journals (Sweden)

    Yeison Alberto Garcés Gómez

    2017-07-01

    Full Text Available Introduction: The use of unified power quality conditioners UPQC in the electric systems can correct waveform distortions in a steady state, like harmonics, flicker, and the power factor. Objective: This paper presents a novel approach for active compensation of overvoltage with a UPQC in dual topology or iUPQC. Methodology: The study it is presented in five stages, the section I shows an introduction and the state of the art, section II presents the unified power quality conditioner UPQC, section III describes the generalized reactive power theory applied to the iUPQC (dual topology, section IV shows the numerical simulations and the results and section V presents the conclusions of the study. Results: The results for the application of the iUPQC to the compensation of overvoltage are proved and compared with the more representative theory related to compensation of harmonics and low power factor. Conclusions: The control algorithm presented for the unified power quality conditioner in dual topology allows to compensate the overvoltage in three-phase systems as well as voltage and current harmonics and the low power factor.

  17. A primer for workers' compensation.

    Science.gov (United States)

    Bible, Jesse E; Spengler, Dan M; Mir, Hassan R

    2014-07-01

    A physician's role within a workers' compensation injury extends far beyond just evaluation and treatment with several socioeconomic and psychological factors at play compared with similar injuries occurring outside of the workplace. Although workers' compensation statutes vary among states, all have several basic features with the overall goal of returning the injured worker to maximal function in the shortest time period, with the least residual disability and shortest time away from work. To help physicians unfamiliar with the workers' compensation process accomplish these goals. Review. Educational review. The streamlined review addresses the topics of why is workers' compensation necessary; what does workers' compensation cover; progression after work injury; impairment and maximum medical improvement, including how to use the sixth edition of American Medical Association's (AMA) Guides to the evaluation of permanent impairment (Guides); completion of work injury claim after impairment rating; independent medical evaluation; and causation. In the "no-fault" workers' compensation system, physicians play a key role in progressing the claim along and, more importantly, getting the injured worker back to work as soon as safely possible. Physicians should remain familiar with the workers' compensation process, along with how to properly use the AMA Guides. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Systemic acute-phase reactants, C-reactive protein and haptoglobin, in adult periodontitis

    Science.gov (United States)

    EBERSOLE, J L; MACHEN, R L; STEFFEN, M J; WILLMANN, D E

    1997-01-01

    Capture ELISAs with biotinylated monospecific antibodies were developed to detect both C-reactive protein (CRP) and haptoglobin (Hp) in serum of adult periodontitis (AP) patients and normal subjects. Each acute-phase reactant was significantly increased in serum from AP patients with CRP at 9.12 ±1.61 mg/l versus 2.17 ± 0.41 mg/l (P acute-phase reactants. The conclusions are that either these molecules are formed locally and distributed to the serum, or these presumably localized infections impact upon the systemic components of the host protective responses. PMID:9030874

  19. Reactive Power Support of Electrical Vehicle Charging Station Upgraded with Flywheel Energy Storage System

    DEFF Research Database (Denmark)

    SUN, BO; Dragicevic, Tomislav; Savaghebi, Mehdi

    2015-01-01

    Electrical vehicles (EVs) are presenting increasingly potential to replace the conventional fossil fuel based vehicles due to environmental friendly characteristic. Accordingly, Charging Stations (CS), as an intermediate between grid and large numbers of EVs, are supposed to have more critical...... influence on future smart transportation network. This paper explores an off-board charging station upgraded with flywheel energy storage system that could provide a reactive power support to the grid utility. A supervisory control scheme based on distributed bus signaling is proposed to coordinate...

  20. Reactivity and kinetic parameters determination in a multiplicative non-stationary system

    International Nuclear Information System (INIS)

    Minguez, E.

    1982-01-01

    A revision of several methods used for solving kinetic equations of a neutronic system is considered. Firstly, kinetic equations in general form are analized, before to revise more important aproximations: point-kinetic method; adiabatic; cuasistatic; eigenvalue equations; nodal, modal and systhesis methods; and variational principles for obtaining kinetic equations. Perturbation theory is used to obtain these parameters, with differents eigenvalue equations representatives of the parameter to be calculated. Also, experimental methods have been included in this work, because of importance the parameters can be measured, and related with those obtained by calculations. Finally, adjoint kinetic equations are resolved to obtain the importance function used in weighted reactivity and kinetic parameters determinations. (author)

  1. Immune System Dysregulation and Herpesvirus Reactivation Persist During Long-Duration Spaceflight

    Science.gov (United States)

    Crucian, B. E.; Mehta, S.; Stowe, R. P.; Uchakin, P.; Quiriarte, H.; Pierson, D.; Sams, C. F.

    2011-01-01

    This poster presentation reviews a study that is designed to address immune system dysregulation and the risk to crewmembers in long duration exploration class missions. This study will address these objectives: (1) Determine the status of adaptive immunity physiological stress, viral immunity, latent herpesvirus reactivation in astronauts during 6 month missions to the International Space Station; (2) determine the clinical risk related to immune dysregulation for exploration class spaceflight; and (3) determine an appropriate monitoring strategy for spaceflight-associated immune dysfunction that could be used for the evaluation of countermeasures. The study anticipates 17 subjects, and for this presentation, (midpoint study data) 10 subjects are reviewed.

  2. Systems and methods for reactive distillation with recirculation of light components

    Science.gov (United States)

    Stickney, Michael J [Nassau Bay, TX; Jones, Jr., Edward M.

    2011-07-26

    Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

  3. Optimal Allocation of Static Var Compensator via Mixed Integer Conic Programming

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaohu [ORNL; Shi, Di [Global Energy Interconnection Research Institute North America (GEIRI North America), California; Wang, Zhiwei [Global Energy Interconnection Research Institute North America (GEIRI North America), California; Huang, Junhui [Global Energy Interconnection Research Institute North America (GEIRI North America), California; Wang, Xu [Global Energy Interconnection Research Institute North America (GEIRI North America), California; Liu, Guodong [ORNL; Tomsovic, Kevin [University of Tennessee, Knoxville (UTK)

    2017-01-01

    Shunt FACTS devices, such as, a Static Var Compensator (SVC), are capable of providing local reactive power compensation. They are widely used in the network to reduce the real power loss and improve the voltage profile. This paper proposes a planning model based on mixed integer conic programming (MICP) to optimally allocate SVCs in the transmission network considering load uncertainty. The load uncertainties are represented by a number of scenarios. Reformulation and linearization techniques are utilized to transform the original non-convex model into a convex second order cone programming (SOCP) model. Numerical case studies based on the IEEE 30-bus system demonstrate the effectiveness of the proposed planning model.

  4. Design of in-situ reactive wall systems - a combined hydraulical-geochemical-economical simulation study

    International Nuclear Information System (INIS)

    Teutsch, G.; Tolksdorff, J.; Schad, H.

    1997-01-01

    The paper presents a coupled hydraulical-geochemical-economical simulation model for the design of in-situ reactive wall systems. More specific, the model is used for cost-optimization and sensitivity analysis of a funnel-and-gate system with an in-situ sorption reactor. The groundwater flow and advective transport are simulated under steady-state conditions using a finite-difference numerical model. This model is coupled to an analytical solution describing the sorption kinetics of hydrophobic organic compounds within the reactor (gate). The third part of the model system is an economical model which calculates (a) the investment costs for the funnel-and-gate construction and (b) the operation cost based on the number of reactor refills, which depends on the breakthrough time for a given contaminant and the anticipated total operation time. For practical applications a simplified approximation of the cost-function is derived and tested

  5. Active and reactive power support of MV distribution systems using battery energy storage

    DEFF Research Database (Denmark)

    Wang, Jiawei; Hashemi Toghroljerdi, Seyedmostafa; You, Shi

    2017-01-01

    shaving and voltage support service from the perspective of Distribution System Operators (DSOs). An active power support algorithm is implemented and the effects of various load profiles as well as different Photovoltaic (PV) penetration scenarios on the operation of BESS and the optimal BESS converter......Adoption of Battery Energy Storage Systems (BESSs) for provision of grid services is increasing. This paper investigates the applications of BESS for the grid upgrade deferral and voltage support of Medium Voltage (MV) distribution systems. A BESS is modelled in Matlab/Simulink to perform peak load...... size for peak load shaving are investigated. The BESS annual lifetime degradation is also estimated using a rainflow counting algorithm. A reactive power support algorithm embedded with Q-U droop control is proposed in order to reduce the voltage drop in a part of 10 kV distribution network of Nordhavn...

  6. Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system

    Directory of Open Access Journals (Sweden)

    Okada Futoshi

    2005-09-01

    Full Text Available Abstract Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems.

  7. Hydro-mechanical model of a reactivated paleo-salt karst system in the Lisan area, Jordan

    Science.gov (United States)

    Closson, Damien; Abou Karaki, Najib

    2015-04-01

    The Dead Sea is a pull-apart basin forming a terminal lake (-429 m) located over the Jordan - Dead Sea transform fault. The slope of the fresh/saline interface is ten times shallower than observed near the ocean because salinity is ten times greater than in the average sea water. Underground lateral extension is acting as a high density layer over which groundwater is in hydrostatic equilibrium. Since the 1960s, a slice of brine 0.033 km x 77 km x 16.5 km vanished due to water resources over-exploitation in the catchment area. Monitoring of wells in the Dead Sea zone indicated that the water table does not drop at the same pace as the lake. The head difference is increasing with time. Groundwater moves so rapidly towards the lake to compensate for the imbalance provoking the proliferation of sinkholes, subsidence, and landslides. Since the 1980s, the emerged spaces have been covered by industrial and touristic infrastructures. Such a dynamic system provides a test bed to study an Early Warning System to help minimizing geo-hazards effects. The reactivation of a paleo-channel located below a US 48 M salt evaporation pond of the Arab Potash Company, Lisan peninsula, provides an illustrative case-study. Sinkholes lineaments whose orientations fit with the main structural directions highlight the role of conduit played by faults and fractures. Rapid underground water circulation explains the appearance of tamarisk in unexpected places. Time series analysis of high and very high resolution visible/radar satellite images acquired from the 1970s and on indicated major changes in the landscape. This work underlines the need of very carefully analyzing all available data sources acquired prior to and during the recession of the lake level before the development of human activities along the coast. This work is supported by the Arab Potash Company. Thanks are due to H.E. Eng. Jaman Sarayreh, Chairman of the Arab Potash Company, and to Dr Dureid Mahasneh et Mr. Bisher

  8. Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2016-01-01

    Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

  9. Development of a 3D optical scanning-based automatic quality assurance system for proton range compensators

    International Nuclear Information System (INIS)

    Kim, MinKyu; Ju, Sang Gyu; Chung, Kwangzoo; Hong, Chae-Seon; Kim, Jinsung; Ahn, Sung Hwan; Jung, Sang Hoon; Han, Youngyih; Chung, Yoonsun; Cho, Sungkoo; Choi, Doo Ho; Kim, Jungkuk; Shin, Dongho

    2015-01-01

    Purpose: A new automatic quality assurance (AutoRCQA) system using a three-dimensional scanner (3DS) with system automation was developed to improve the accuracy and efficiency of the quality assurance (QA) procedure for proton range compensators (RCs). The system performance was evaluated for clinical implementation. Methods: The AutoRCQA system consists of a three-dimensional measurement system (3DMS) based on 3DS and in-house developed verification software (3DVS). To verify the geometrical accuracy, the planned RC data (PRC), calculated with the treatment planning system (TPS), were reconstructed and coregistered with the measured RC data (MRC) based on the beam isocenter. The PRC and MRC inner surfaces were compared with composite analysis (CA) using 3DVS, using the CA pass rate for quantitative analysis. To evaluate the detection accuracy of the system, the authors designed a fake PRC by artificially adding small cubic islands with side lengths of 1.5, 2.5, and 3.5 mm on the inner surface of the PRC and performed CA with the depth difference and distance-to-agreement tolerances of [1 mm, 1 mm], [2 mm, 2 mm], and [3 mm, 3 mm]. In addition, the authors performed clinical tests using seven RCs [computerized milling machine (CMM)-RCs] manufactured by CMM, which were designed for treating various disease sites. The systematic offsets of the seven CMM-RCs were evaluated through the automatic registration function of AutoRCQA. For comparison with conventional technique, the authors measured the thickness at three points in each of the seven CMM-RCs using a manual depth measurement device and calculated thickness difference based on the TPS data (TPS-manual measurement). These results were compared with data obtained from 3DVS. The geometrical accuracy of each CMM-RC inner surface was investigated using the TPS data by performing CA with the same criteria. The authors also measured the net processing time, including the scan and analysis time. Results: The Auto

  10. Development of a 3D optical scanning-based automatic quality assurance system for proton range compensators

    Energy Technology Data Exchange (ETDEWEB)

    Kim, MinKyu; Ju, Sang Gyu, E-mail: sg.ju@samsung.com, E-mail: doho.choi@samsung.com; Chung, Kwangzoo; Hong, Chae-Seon; Kim, Jinsung; Ahn, Sung Hwan; Jung, Sang Hoon; Han, Youngyih; Chung, Yoonsun; Cho, Sungkoo; Choi, Doo Ho, E-mail: sg.ju@samsung.com, E-mail: doho.choi@samsung.com [Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, Jungkuk [Department of Electronics Engineering, Myongji University, Gyeonggi-do 449-728 (Korea, Republic of); Shin, Dongho [Proton Therapy Center, National Cancer Center, Gyeonggi-do 410-769 (Korea, Republic of)

    2015-02-15

    Purpose: A new automatic quality assurance (AutoRCQA) system using a three-dimensional scanner (3DS) with system automation was developed to improve the accuracy and efficiency of the quality assurance (QA) procedure for proton range compensators (RCs). The system performance was evaluated for clinical implementation. Methods: The AutoRCQA system consists of a three-dimensional measurement system (3DMS) based on 3DS and in-house developed verification software (3DVS). To verify the geometrical accuracy, the planned RC data (PRC), calculated with the treatment planning system (TPS), were reconstructed and coregistered with the measured RC data (MRC) based on the beam isocenter. The PRC and MRC inner surfaces were compared with composite analysis (CA) using 3DVS, using the CA pass rate for quantitative analysis. To evaluate the detection accuracy of the system, the authors designed a fake PRC by artificially adding small cubic islands with side lengths of 1.5, 2.5, and 3.5 mm on the inner surface of the PRC and performed CA with the depth difference and distance-to-agreement tolerances of [1 mm, 1 mm], [2 mm, 2 mm], and [3 mm, 3 mm]. In addition, the authors performed clinical tests using seven RCs [computerized milling machine (CMM)-RCs] manufactured by CMM, which were designed for treating various disease sites. The systematic offsets of the seven CMM-RCs were evaluated through the automatic registration function of AutoRCQA. For comparison with conventional technique, the authors measured the thickness at three points in each of the seven CMM-RCs using a manual depth measurement device and calculated thickness difference based on the TPS data (TPS-manual measurement). These results were compared with data obtained from 3DVS. The geometrical accuracy of each CMM-RC inner surface was investigated using the TPS data by performing CA with the same criteria. The authors also measured the net processing time, including the scan and analysis time. Results: The Auto

  11. Technical Basis for Peak Reactivity Burnup Credit for BWR Spent Nuclear Fuel in Storage and Transportation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL; Ade, Brian J [ORNL; Bowman, Stephen M [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Mertyurek, Ugur [ORNL; Radulescu, Georgeta [ORNL

    2015-01-01

    Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate application of burnup credit for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase (1) investigates applicability of peak reactivity methods currently used in spent fuel pools (SFPs) to storage and transportation systems and (2) evaluates validation of both reactivity (keff) calculations and burnup credit nuclide concentrations within these methods. The second phase will focus on extending burnup credit beyond peak reactivity. This paper documents the first phase, including an analysis of lattice design parameters and depletion effects, as well as both validation components. Initial efforts related to extended burnup credit are discussed in a companion paper. Peak reactivity analyses have been used in criticality analyses for licensing of BWR fuel in SFPs over the last 20 years. These analyses typically combine credit for the gadolinium burnable absorber present in the fuel with a modest amount of burnup credit. Gadolinium burnable absorbers are used in BWR assemblies to control core reactivity. The burnable absorber significantly reduces assembly reactivity at beginning of life, potentially leading to significant increases in assembly reactivity for burnups less than 15–20 GWd/MTU. The reactivity of each fuel lattice is dependent on gadolinium loading. The number of gadolinium-bearing fuel pins lowers initial lattice reactivity, but it has a small impact on the burnup and reactivity of the peak. The gadolinium concentration in each pin has a small impact on initial lattice reactivity but a significant effect on the reactivity of the peak and the burnup at which the peak occurs. The importance of the lattice parameters and depletion conditions are primarily determined by their impact on the gadolinium depletion. Criticality code validation for BWR burnup

  12. A design of cascade control system and adaptive load compensator for battery/ultracapacitor hybrid energy storage-based direct current microgrid

    International Nuclear Information System (INIS)

    Pavković, Danijel; Lobrović, Mihael; Hrgetić, Mario; Komljenović, Ante

    2016-01-01

    Highlights: • Battery/ultracapacitor storage is considered for a direct-current microgrid. • Microgrid voltage cascade control system with load compensator is designed. • Current references are allocated so that ultracapacitor takes on transient loads. • Adaptive Kalman filter-based estimator is used for indirect load compensation. • Control strategy has been verified on a downscaled hardware-in-the-loop setup. - Abstract: A control system design based on an actively-controlled battery/ultracapacitor hybrid energy storage system suitable for direct current microgrid energy management purposes is presented in this paper. The proposed cascade control system arrangement is based on the superimposed proportional–integral voltage controller designed according to Damping Optimum criterion and a zero-pole canceling feed-forward load compensator aimed at voltage excursion suppression under variable load conditions. The superimposed controller commands the inner battery and ultracapacitor current control loops through a dynamic current reference distribution scheme, wherein the ultracapacitor takes on the highly-dynamic (transient) current demands, and the battery covers for steady-state loads. In order to avoid deep discharges of the ultracapacitor module, it is equipped with an auxiliary state-of-charge controller. Finally, for those applications where load is not measured, an adaptive Kalman filter-based load compensator is proposed and tested. The presented control strategy has been implemented on the low-cost industrial controller unit, and its effectiveness has been verified by means of simulations and experiments for the cases of abrupt load changes and quasi-stochastic load profiles using a downscaled battery/ultracapacitor hardware-in-the-loop experimental setup.

  13. An Enhanced Power Sharing Scheme for Voltage unbalance and harmonics compensation in an islanded AC microgrid

    DEFF Research Database (Denmark)

    Han, Yang; Shen, Pan; Zhao, Xin

    2016-01-01

    In this paper, an enhanced hierarchical control structure with multiple current loop damping schemes for voltage unbalance and harmonics compensation in ac islanded microgrid is proposed to address unequal power sharing problems. The distributed generation (DG) is properly controlled to autonomou......In this paper, an enhanced hierarchical control structure with multiple current loop damping schemes for voltage unbalance and harmonics compensation in ac islanded microgrid is proposed to address unequal power sharing problems. The distributed generation (DG) is properly controlled...... to autonomously compensate voltage unbalance and harmonics while sharing the compensation effort for the real power, reactive power, unbalance and harmonic powers. The proposed control system of the microgrid mainly consists of the positive sequence real and reactive power droop controllers, voltage and current...... controllers, the selective virtual impedance loop, the unbalance and harmonics compensators, the secondary control for voltage amplitude and frequency restoration, and the auxiliary control to achieve a high voltage quality at the point of common coupling (PCC). By using the proposed unbalance and harmonics...

  14. Parental management of peers and autonomic nervous system reactivity in predicting adolescent peer relationships.

    Science.gov (United States)

    Tu, Kelly M; Erath, Stephen A; El-Sheikh, Mona

    2017-03-01

    The present study examined sympathetic and parasympathetic indices of autonomic nervous system reactivity as moderators of the prospective association between parental management of peers via directing of youths' friendships and peer adjustment in a sample of typically developing adolescents. Participants included 246 adolescents at Time 1 (T1) [47% boys; 66% European American (EA), 34% African American (AA)] and 226 adolescents at Time 2 (T2; 45% boys; 67% EA, 33% AA). Adolescents were approximately 16 and 17 years old at T1 and T2, respectively. To address study aims, a multiinformant, multimethod longitudinal design was utilized. Skin conductance level (SCL) and respiratory sinus arrhythmia (RSA) were measured during a baseline period and challenge task (star-tracing). Reactivity was computed as a difference score between the task and baseline period. Results from path models revealed that higher levels of mother-reported parental directing predicted decreases in adolescent-reported peer rejection and friends' deviant behavior from T1 to T2 at relatively low levels of physiological arousal in response to challenge (i.e., low SCL reactivity, RSA augmentation). Further, exploratory analyses indicated that directing was associated with decreases in friends' deviant behavior and peer rejection particularly among boys who exhibited lower levels of physiological arousal, but increases in friends' deviant behavior among boys who exhibited higher levels of arousal reflected in RSA withdrawal only. Overall, findings are consistent with prior studies revealing the benefits of parental behavioral control for underaroused youth, contributing to the growing literature on the interplay of parenting and physiological factors in the adolescent peer domain. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Internally directed cognition and mindfulness: an integrative perspective derived from predictive and reactive control systems theory

    Science.gov (United States)

    Tops, Mattie; Boksem, Maarten A. S.; Quirin, Markus; IJzerman, Hans; Koole, Sander L.

    2013-01-01

    In the present paper, we will apply the predictive and reactive control systems (PARCS) theory as a framework that integrates competing theories of neural substrates of awareness by describing the “default mode network” (DMN) and anterior insula (AI) as parts of two different behavioral and homeostatic control systems. The DMN, a network that becomes active at rest when there is no external stimulation or task to perform, has been implicated in self-reflective awareness and prospection. By contrast, the AI is associated with awareness and task-related attention. This has led to competing theories stressing the role of the DMN in self-awareness vs. the role of interoceptive and emotional information integration in the AI in awareness of the emotional moment. In PARCS, the respective functions of the DMN and AI in a specific control system explains their association with different qualities of awareness, and how mental states can shift from one state (e.g., prospective self-reflection) to the other (e.g., awareness of the emotional moment) depending on the relative dominance of control systems. These shifts between reactive and predictive control are part of processes that enable the intake of novel information, integration of this novel information within existing knowledge structures, and the creation of a continuous personal context in which novel information can be integrated and understood. As such, PARCS can explain key characteristics of mental states, such as their temporal and spatial focus (e.g., a focus on the here and now vs. the future; a first person vs. a third person perspective). PARCS further relates mental states to brain states and functions, such as activation of the DMN or hemispheric asymmetry in frontal cortical functions. Together, PARCS deepens the understanding of a broad range of mental states, including mindfulness, mind wandering, rumination, autobiographical memory, imagery, and the experience of self. PMID:24904455

  16. Permissive Parenting, Deviant Peer Affiliations, and Delinquent Behavior in Adolescence: the Moderating Role of Sympathetic Nervous System Reactivity.

    Science.gov (United States)

    Hinnant, J Benjamin; Erath, Stephen A; Tu, Kelly M; El-Sheikh, Mona

    2016-08-01

    The present study examined two measures of sympathetic nervous system (SNS) activity as moderators of the indirect path from permissive parenting to deviant peer affiliations to delinquency among a community sample of adolescents. Participants included 252 adolescents (M = 15.79 years; 53 % boys; 66 % European American, 34 % African American). A multi-method design was employed to address the research questions. Two indicators of SNS reactivity, skin conductance level reactivity (SCLR) and cardiac pre-ejection period reactivity (PEPR) were examined. SNS activity was measured during a baseline period and a problem-solving task (star-tracing); reactivity was computed as the difference between the task and baseline periods. Adolescents reported on permissive parenting, deviant peer affiliations, externalizing behaviors, and substance use (alcohol, marijuana). Analyses revealed indirect effects between permissive parenting and delinquency via affiliation with deviant peers. Additionally, links between permissive parenting to affiliation with deviant peers and affiliation with deviant peers to delinquency was moderated by SNS reactivity. Less SNS reactivity (less PEPR and/or less SCLR) were risk factors for externalizing problems and alcohol use. Findings highlight the moderating role of SNS reactivity in parenting and peer pathways that may contribute to adolescent delinquency and point to possibilities of targeted interventions for vulnerable youth.

  17. Modeling reactive transport in non-ideal aqueous-solid solution system

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Haibing, E-mail: haibing.shao@ufz.de [UFZ-Helmholtz Centre for Environmental Research, Department Environmental Informatics, Permoserstrasse 15, 04318 Leipzig (Germany)] [Applied Environmental System Analysis, TU Dresden, Helmholtzstrasse 10, 01069 Dresden (Germany); Dmytrieva, Svitlana V. [SSC Technocentre, Nauky Prosp. 46, 03650 Kyiv (Ukraine)] [Laboratory for Waste Management, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Kolditz, Olaf [UFZ-Helmholtz Centre for Environmental Research, Department Environmental Informatics, Permoserstrasse 15, 04318 Leipzig (Germany)] [Applied Environmental System Analysis, TU Dresden, Helmholtzstrasse 10, 01069 Dresden (Germany); Kulik, Dmitrii A.; Pfingsten, Wilfried; Kosakowski, Georg [Laboratory for Waste Management, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2009-07-15

    The numerical simulation of reactive mass transport processes in complex geochemical environments is an important tool for the performance assessment of future waste repositories. A new combination of the multi-component mass transport code GeoSys/RockFlow and the Gibbs Energy Minimization (GEM) equilibrium solver GEM-Selektor is used to calculate the accurate equilibrium of multiple non-ideal solid solutions which are important for the immobilization of radionuclides such as Ra. The coupled code is verified by a widely used benchmark of dissolution-precipitation in a calcite-dolomite system. A more complex application shown in this paper is the transport of Ra in the near-field of a nuclear waste repository. Depending on the initial inventories of Sr, Ba and sulfate, non-ideal sulfate and carbonate solid solutions can fix mobile Ra cations. Due to the complex geochemical interactions, the reactive transport simulations can describe the migration of Ra in a much more realistic way than using the traditional linear K{sub D} approach only.

  18. Rare events in many-body systems: reactive paths and reaction constants for structural transitions

    International Nuclear Information System (INIS)

    Picciani, M.

    2012-01-01

    This PhD thesis deals with the study of fundamental physics phenomena, with applications to nuclear materials of interest. We have developed methods for the study of rare events related to thermally activated structural transitions in many body systems. The first method involves the numerical simulation of the probability current associated with reactive paths. After deriving the evolution equations for the probability current, a Diffusion Monte Carlo algorithm is implemented in order to sample this current. This technique, called Transition Current Sampling was applied to the study of structural transitions in a cluster of 38 atoms with Lennard-Jones potential (LJ-38). A second algorithm, called Transition Path Sampling with local Lyapunov bias (LyTPS), was then developed. LyTPS calculates reaction rates at finite temperature by following the transition state theory. A statistical bias based on the maximum local Lyapunov exponents is introduced to accelerate the sampling of reactive trajectories. To extract the value of the equilibrium reaction constants obtained from LyTPS, we use the Multistate Bennett Acceptance Ratio. We again validate this method on the LJ-38 cluster. LyTPS is then used to calculate migration constants for vacancies and divacancies in the α-Iron, and the associated migration entropy. These constants are used as input parameter for codes modeling the kinetic evolution after irradiation (First Passage Kinetic Monte Carlo) to reproduce numerically resistivity recovery experiments in α-Iron. (author) [fr

  19. Application of Solid State Static Var Compensation and Stability Enhancements.

    Science.gov (United States)

    Hussain, Badruzzaman

    Since the development of large scale electric power system interconnection, power engineering has gone through enormous changes and many new power system dynamic problems have emerged. Among them, the low frequency power oscillations between intersystem have been a major concern and is the issue in this research. In this research an effective and efficient method of controlling reactive power is presented. This research shows that spontaneous introduction of small power oscillations in the interconnected network system can be effectively suppressed by an unique method of solid state reactive power compensation. The capability of power electronics is discussed in reasonable detail to justify the feasibility of solid state reactive power generation. Mathematical formulation is carried out to control the reactive power which in turn controls the dynamics of the interconnected power system by improving the damping of interties in the system. The presently installed power system stabilizers are compared with this approach for a single machine infinite bus system. In this research, the formulation is shown to be effective for centralized multi-mode, multimachine systems. The study of the system for small power oscillations is based upon the analysis of eigenvalues of the electromechanical modes of the system. Transient stability problem is also emphasized in this research. It is shown that the system undergoing a large disturbance or severe fault can be stabilized by utilizing a discrete voltage rise in the system. This is achieved by operating the SSSVC with its maximum capacity leading mode, immediately after the inception of a fault or disturbance in the system. It is demonstrated that using this control scheme, the critical clearing time of the system can be increased significantly, which enables the operator to incorporate various corrective actions to minimize the system power imbalance.

  20. Crime victims‘ right to compensation

    Directory of Open Access Journals (Sweden)

    Mrvić-Petrović Nataša

    2012-01-01

    Full Text Available This paper analyzes the most important documents of the United Nations, Council of Europe and the European Union relating to rights to damage compensation (restitution from offender and state compensation. The analysis shows that there is a gradual move from the concept of exercising the rights of victims in favor of a solidaristic model that takes less into account the rights of victims, and more the need to satisfy their legitimate interests. The economic crisis that is undermining the foundations of the welfare state could jeopardize the realization of this concept, especially in those European countries where the criminal justice system focuses solely on the offender, as is the case in Serbia. In such circumstances, regulation which protects the right to compensation, other rights and interests of victims, shall apply only to the extent that serves crime prevention. So it happens that in spite of a suitable normative framework and developments regarding the protection of victims of domestic violence and trafficking, the right to compensation and other rights of the victims do not actually get actualized in practice. In order to overcome this, a systemic reform to the criminal justice system should be undertaken with the aim to redirect the system towards the victim of the offense. Within these reforms a public fund for compensation of the victims of violence should be established and the process of mediation between the victim and the offender with the goal to make a settlement should be regulated, because these mechanisms do not exist in Serbia.

  1. Compensation of nonlinearity in a fiber-optic transmission system using frequency-degenerate phase conjugation through counter-propagating dual pump FWM in a semiconductor optical amplifier

    Science.gov (United States)

    Anchal, Abhishek; K, Pradeep Kumar; O'Duill, Sean; Anandarajah, Prince M.; Landais, Pascal

    2018-04-01

    We present a scheme of frequency-degenerate mid-span spectral inversion (MSSI) for nonlinearity compensation in fiber-optic transmission systems. The spectral inversion is obtained by using counter-propagating dual pump four-wave mixing in a semiconductor optical amplifier (SOA). Frequency-degeneracy between signal and conjugate is achieved by keeping two pump frequencies symmetrical about the signal frequency. We simulate the performance of MSSI for nonlinearity compensation by scrutinizing the improvement of the Q-factor of a 200 Gbps QPSK signal transmitted over a standard single mode fiber, as a function of launch power for different span lengths and number of spans. We demonstrate a 7.5 dB improvement in the input power dynamic range and an almost 83% increase in the transmission length for optimum MSSI parameters of -2 dBm pump power and 400 mA SOA current.

  2. Compensation temperatures of mixed spin-2 and spin-((5)/(2)) ferrimagnetic system with interlayer coupling; a study of a molecular-based magnet

    CERN Document Server

    Zhang Qi

    2002-01-01

    Compensation points of layer system consisting of mixed spin-2 and spin-((5)/(2)) ferrimagnetic honeycomb lattice layers which are coupled together with two kinds of positive interlayer coupling are examined by the use of the effective-field theory with correlations (EFT). In particular, the effects of interlayer coupling and a positive crystal-field constant of the spin-2 ions on the compensation temperature are investigated, in order to clarify the characteristic behavior of the temperature dependence of the total magnetization M. This is related to the experimental works of a molecular-based magnetic multilayer film, N(n-C sub 4 H sub 9) sub 4 Fe sup I sup I Fe sup I sup I sup I (C sub 2 O sub 4) sub 3. A comparison is made between the results in this paper and those in a previous work obtained by using Monte-Carlo simulations.

  3. Rate dependent direct inverse hysteresis compensation of piezoelectric micro-actuator used in dual-stage hard disk drive head positioning system

    Science.gov (United States)

    Rahman, Md. Arifur; Al Mamun, Abdullah; Yao, Kui

    2015-08-01

    The head positioning servo system in hard disk drive is implemented nowadays using a dual-stage actuator—the primary stage consisting of a voice coil motor actuator providing long range motion and the secondary stage controlling the position of the read/write head with fine resolution. Piezoelectric micro-actuator made of lead zirconate titanate (PZT) has been a popular choice for the secondary stage. However, PZT micro-actuator exhibits hysteresis—an inherent nonlinear characteristic of piezoelectric material. The advantage expected from using the secondary micro-actuator is somewhat lost by the hysteresis of the micro-actuator that contributes to tracking error. Hysteresis nonlinearity adversely affects the performance and, if not compensated, may cause inaccuracy and oscillation in the response. Compensation of hysteresis is therefore an important aspect for designing head-positioning servo system. This paper presents a new rate dependent model of hysteresis along with rigorous analysis and identification of the model. Parameters of the model are found using particle swarm optimization. Direct inverse of the proposed rate-dependent generalized Prandtl-Ishlinskii model is used as the hysteresis compensator. Effectiveness of the overall solution is underscored through experimental results.

  4. Dynamic Consensus Algorithm based Distributed Unbalance Compensation in Islanded Microgrids

    DEFF Research Database (Denmark)

    Meng, Lexuan; Zhao, Xin; Firoozabadi, Mehdi Savaghebi

    2015-01-01

    compensation, droop control and virtual impedance can be applied in primary control to help the positive sequence active and reactive power sharing. Secondary control is used to assist voltage unbalance compensation. However, if transmission line differences are considered, the negative sequence current cannot...

  5. Reactive solute transport in an asymmetrical fracture-rock matrix system

    Science.gov (United States)

    Zhou, Renjie; Zhan, Hongbin

    2018-02-01

    The understanding of reactive solute transport in a single fracture-rock matrix system is the foundation of studying transport behavior in the complex fractured porous media. When transport properties are asymmetrically distributed in the adjacent rock matrixes, reactive solute transport has to be considered as a coupled three-domain problem, which is more complex than the symmetric case with identical transport properties in the adjacent rock matrixes. This study deals with the transport problem in a single fracture-rock matrix system with asymmetrical distribution of transport properties in the rock matrixes. Mathematical models are developed for such a problem under the first-type and the third-type boundary conditions to analyze the spatio-temporal concentration and mass distribution in the fracture and rock matrix with the help of Laplace transform technique and de Hoog numerical inverse Laplace algorithm. The newly acquired solutions are then tested extensively against previous analytical and numerical solutions and are proven to be robust and accurate. Furthermore, a water flushing phase is imposed on the left boundary of system after a certain time. The diffusive mass exchange along the fracture/rock matrixes interfaces and the relative masses stored in each of three domains (fracture, upper rock matrix, and lower rock matrix) after the water flushing provide great insights of transport with asymmetric distribution of transport properties. This study has the following findings: 1) Asymmetric distribution of transport properties imposes greater controls on solute transport in the rock matrixes. However, transport in the fracture is mildly influenced. 2) The mass stored in the fracture responses quickly to water flushing, while the mass stored in the rock matrix is much less sensitive to the water flushing. 3) The diffusive mass exchange during the water flushing phase has similar patterns under symmetric and asymmetric cases. 4) The characteristic distance

  6. Switching Overvoltages in 60 kV reactor compensated cable grid due to resonance after disconnection

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Baldursson, Haukur; Oumarou, Abdoul M.

    2008-01-01

    Some electrical distribution companies are nowadays replacing overhead lines with underground cables. These changes from overhead to underground cable provoke an increased reactive power production in the grid. To save circuit breakers the reactors needed for compensating this excessive reactive...

  7. An Efficient Reactive Power Control Method for Power Network Systems with Solar Photovoltaic Generators Using Sparse Optimization

    Directory of Open Access Journals (Sweden)

    Yu Li

    2017-05-01

    Full Text Available With the incremental introduction of solar photovoltaic (PV generators into existing power systems, and their fast-growing share in the gross electricity generation, system voltage stability has become a critical issue. One of the major concerns is voltage fluctuation, due to large and random penetration of solar PV generators. To suppress severe system voltage deviation, reactive power control of the photovoltaic system inverter has been widely proposed in recent works; however, excessive use of reactive power control would increase both initial and operating costs. In this paper, a method for efficient allocation and control of reactive power injection using the sparse optimization technique is proposed. Based on a constrained linearized model describing the influence of reactive power injection on voltage magnitude change, the objective of this study is formulated as an optimization problem, which aims to find the best reactive power injection that minimizes the whole system voltage variation. Two types of formulations are compared: the first one is the conventional least-square optimization, while the second one is adopted from a sparse optimization technique, called the constrained least absolute shrinkage and selection operator (LASSO method. The constrained LASSO method adds ℓ 1 -norm penalty to the total reactive power injection, which contributes to the suppression of the number of control nodes with non-zero reactive power injection. The authors analyzed the effectiveness of the constrained LASSO method using the IEEE 39-bus and 57-bus power network as benchmark examples, under various PV power generation and allocation patterns. The simulation results show that the constrained LASSO method automatically selects the minimum number of inverters required for voltage regulation at the current operating point.

  8. Multi-objective Reactive Power Optimization Based on Improved Particle Swarm Algorithm

    Science.gov (United States)

    Cui, Xue; Gao, Jian; Feng, Yunbin; Zou, Chenlu; Liu, Huanlei

    2018-01-01

    In this paper, an optimization model with the minimum active power loss and minimum voltage deviation of node and maximum static voltage stability margin as the optimization objective is proposed for the reactive power optimization problems. By defining the index value of reactive power compensation, the optimal reactive power compensation node was selected. The particle swarm optimization algorithm was improved, and the selection pool of global optimal and the global optimal of probability (p-gbest) were introduced. A set of Pareto optimal solution sets is obtained by this algorithm. And by calculating the fuzzy membership value of the pareto optimal solution sets, individuals with the smallest fuzzy membership value were selected as the final optimization results. The above improved algorithm is used to optimize the reactive power of IEEE14 standard node system. Through the comparison and analysis of the results, it has been proven that the optimization effect of this algorithm was very good.

  9. Active superconducting DC fault current limiter based on flux compensation

    International Nuclear Information System (INIS)

    Shi Jing; Tang Yuejin; Wang, Chen; Zhou Yusheng; Li Jingdong; Ren Li; Chen Shijie

    2006-01-01

    With the extensive application of DC power systems, suppression of DC fault current is an important subject that guarantees system security. This paper presents an active superconducting DC fault current limiter (DC-SFCL) based on flux compensation. The DC-SFCL is composed of two superconducting windings wound on a single iron core, the primary winding is in series with DC power system, and the second winding is connected with AC power system through a PWM converter. In normal operating state, the flux in the iron core is compensated to zero, and the SFCL has no influence on DC power system. In the case of DC system accident, through regulating the active power exchange between the SFCL's second winding and the AC power system, the current on the DC side can be limited to different level complying with the system demand. Moreover, the PWM converter that interface the DC system and AC system can be controlled as a reactive power source to supply voltage support for the AC side, which has little influence on the performance of SFCL. Using MATLAB SIMULINK, the mathematic model of the DC-SFCL is created, simulation results validate the dynamics of system, and the performance of DC-SFCL is confirmed

  10. Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation

    Science.gov (United States)

    Sudhakar, N.; Jain, Siddhartha; Jyotheeswara Reddy, K.

    2017-11-01

    This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.

  11. Catalytic reactive separation system for energy-efficient production of cumene

    Science.gov (United States)

    Buelna, Genoveva [Nuevo Laredo, MX; Nenoff, Tina M [Albuquerque, NM

    2009-07-28

    The present invention relates to an atmospheric pressure, reactive separation column packed with a solid acid zeolite catalyst for producing cumene from the reaction of benzene with propylene. Use of this un-pressurized column, where simultaneous reaction and partial separation occur during cumene production, allow separation of un-reacted, excess benzene from other products as they form. This high-yielding, energy-efficient system allows for one-step processing of cumene, with reduced need for product purification. Reacting propylene and benzene in the presence of beta zeolite catalysts generated a selectivity greater than 85% for catalytic separation reactions at a reaction temperature of 115 degrees C and at ambient pressure. Simultaneously, up to 76% of un-reacted benzene was separated from the product; which could be recycled back to the reactor for re-use.

  12. Reactivity on the Web

    OpenAIRE

    Bailey, James; Bry, François; Eckert, Michael; Patrânjan, Paula Lavinia

    2005-01-01

    Reactivity, the ability to detect simple and composite events and respond in a timely manner, is an essential requirement in many present-day information systems. With the emergence of new, dynamic Web applications, reactivity on the Web is receiving increasing attention. Reactive Web-based systems need to detect and react not only to simple events but also to complex, real-life situations. This paper introduces XChange, a language for programming reactive behaviour on the Web,...

  13. Options in Compensation

    DEFF Research Database (Denmark)

    Flor, Christian Riis; Frimor, Hans; Munk, Claus

    2014-01-01

    to motivate effort. If rewarding low outcomes is infeasible, compensation consisting of stocks and options is a near-efficient means of overcoming the manager's induced aversion to undertaking risky investments, whereas stock compensation is not. However, stock plus option compensation may induce excessively...

  14. Laboratory tests in support of the MSRE reactive gas removal system

    International Nuclear Information System (INIS)

    Rudolph, J.C.; Del Cul, G.D.; Caja, J.; Toth, L.M.; Williams, D.F.; Thomas, K.S.; Clark, D.E.

    1997-07-01

    The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory has been shut down since December 1969, at which time the molten salt mixture of LiF-BeF 2 -ZrF 4 - 233 UF 4 (64.5-30.3-5.0-0.13 mol%) was transferred to fuel salt drain tanks for storage. In the late 1980s, increased radiation in one of the gas lines from the drain tank was attributed to 233 UF 6 . In 1994 two gas samples were withdraw (from a gas line in the Vent House connecting to the drain tanks) and analyzed. Surprisingly, 350 mm Hg of F 2 , 70 mm Hg of UF 6 , and smaller amounts of other gases were found in both of the samples. To remote this gas from above the drain tanks and all of the associated piping, the reactive gas removal system (RGRS) was designed. This report details the laboratory testing of the RGRS, using natural uranium, prior to its implementation at the MSRE facility. The testing was performed to ensure that the equipment functioned properly and was sufficient to perform the task while minimizing exposure to personnel. In addition, the laboratory work provided the research and development effort necessary to maximize the performance of the system. Throughout this work technicians and staff who were to be involved in RGRS operation at the MSRE site worked directly with the research staff in completing the laboratory testing phase. Consequently, at the end of the laboratory work, the personnel who were to be involved in the actual operations had acquired all of the training and experience necessary to continue with the process of reactive gas removal

  15. Effects of Riot Control Training on Systemic Microvascular Reactivity and Capillary Density.

    Science.gov (United States)

    Pereira, Flavio; de Moraes, Roger; Van Bavel, Diogo; De Lorenzo, Andrea; Tibirica, Eduardo

    2018-03-14

    The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density. Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH). Functional capillary density was assessed using high-resolution, intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using PORH. Microcirculatory tests were performed before and after a 5-wk special military training for riot control. Microvascular endothelium-dependent vasodilatory responses were markedly and significantly reduced after training, compared with values obtained before training. The peak values of microvascular conductance obtained during iontophoresis of ACh or PORH before training (0.84 ± 0.22 and 0.94 ± 0.72 APU/mmHg, respectively) were markedly reduced after training (0.47 ± 0.11 and 0.71 ± 0.14 APU/mmHg; p < 0.0001 and p = 0.0037, respectively). Endothelium-dependent capillary recruitment was significantly reduced after training (before 101 ± 9 and after 95 ± 8 capillaries/mm2; p = 0.0007). The present study showed that a 5-wk strenuous military training, performed in unfavorable climatic conditions, induces marked systemic microvascular dysfunction, mainly characterized by reduced endothelium-dependent microvascular vasodilation and blunted capillary recruitment.

  16. RMR. A new portable Reactivity Measuring System installed at NPP Paks

    International Nuclear Information System (INIS)

    Czibok, T.; Horvath, C.; Bara, P.; Dezsoe, Z.; Laz, J.; Vegh, J.; Pos, I.

    2003-01-01

    The Hungarian Paks NPP is conducting a two year project for upgrading the reactivity measuring system applied during reactor startup experiments. The NPP has decided to replace almost all components of the previous system, only ionisation chambers remain unaltered. Devices for measuring neutron flux by means of ionisation chambers, for data acquisition and for measurement evaluation were completely renewed: new hardware-software components were introduced. Autonomous, high-precision current measuring systems (picoampere meters) are applied at each reactor unit, the converted picoampere signals are handled by a portable processing unit. The portable unit - based on a notebook PC - handles measured signals by using a high-precision A/D converter card, the scan time is 0.10 sec. In addition to handling three ionisation chamber signals the portable unit collects control rod position measurements through a serial line. The portable unit is able to receive additional measured data (e.g. core inlet temperature and boron concentration) from the process computer via local area network. Archiving of all measured and calculated data is performed in a redundant manner: data are stored locally and in the process computer, as well. The new system applies an accurate on-line reactivity calculation algorithm based on the point-kinetic model with 6 delayed neutron groups. Input data (effective delayed neutron fraction and other delayed neutron parameters) to the on-line calculation are taken from the off-line core design calculation. Detailed evaluation and analysis of startup measurements can be performed also on the portable unit. The user interface of the system is tailored to support various startup measurement tasks effectively: measured and calculated data are displayed on trends and on dedicated pictures. A user-friendly trending and listing graphic tool facilitates visualisation of archived data. The paper describes the architecture, data acquisition modules, algorithms and

  17. DC-link Voltage Control to Compensate Voltage Deviation for PV–BESSs Integrated System in Low-Voltage (LV Networks

    Directory of Open Access Journals (Sweden)

    Lee Gyu-sub

    2016-01-01

    Full Text Available The exhaustion of fossil fuel and the greenhouse gas emission are one of the most significant energy and environmental issues, respectively. Photovoltaic (PV generators and battery energy storage systems (BESSs have been significantly increased for recent years. The BESSs are mainly used for smoothing active power fluctuation of the PV. In this paper, PV–BESSs integration of two DC/DC converters and one AC/DC converter is investigated and DC-link voltage control to compensate the AC voltage deviation is proposed for the PV‒BESS system in low-voltage (LV networks.

  18. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  19. Two-layer elastic element of the compensator for the errors of the «press-and-die» system design improvement

    Directory of Open Access Journals (Sweden)

    Олена Юріївна Балалаєва

    2015-10-01

    Full Text Available The article presents the improved design of the elastic element of the slide direction error compensator. The two-layer elastic element consisting of upper and lower elastic plates of variable thickness is placed between supporting surfaces of the slide and the die upper plate. The joint between the upper and lower plates is stepped The rigidity of this compound elastic element is specified so that at the processing load deformation of the elastic element can not exceed 20-25% of its total height. The optimal value of the horizontal displacement of the upper plate necessary to achieve the necessary rigidity of the elastic element is defined in the article. It has been found that the displacement of the upper plate of of two-layer elastic element should be multiple to the height of the press bed deformation at processing loads. Variable thickness of the compound elastic element may also be used to adjust the interdie space. The processing loads range has been widened as well as the application of the compensator for the «press-and-die» system errors. The proposed design of the compensator elastic element is simple and with minimum of expenses, makes it possible to withstand several million compression cycles

  20. Development of novel control system to grow ZnO thin films by reactive evaporation

    Directory of Open Access Journals (Sweden)

    Gerardo Gordillo

    2016-07-01

    Full Text Available This work describes a novel system implemented to grow ZnO thin films by plasma assisted reactive evaporation with adequate properties to be used in the fabrication of photovoltaic devices with different architectures. The innovative aspect includes both an improved design of the reactor used to activate the chemical reaction that leads to the formation of the ZnO compound as an electronic system developed using the virtual instrumentation concept. ZnO thin films with excellent opto-electrical properties were prepared in a reproducible way, controlling the deposition system through a virtual instrument (VI with facilities to control the amount of evaporated zinc involved in the process that gives rise to the formation of ZnO, by means of the incorporation of PID (proportional integral differential and PWM (pulse width modulation control algorithms. The effectiveness and reliability of the developed system was verified by obtaining with good reproducibility thin films of n+-ZnO and i-ZnO grown sequentially in situ with thicknesses and resistivities suitable for use as window layers in chalcopyrite based thin film solar cells.

  1. Path integrals for electronic densities, reactivity indices, and localization functions in quantum systems.

    Science.gov (United States)

    Putz, Mihai V

    2009-11-10

    The density matrix theory, the ancestor of density functional theory, provides the immediate framework for Path Integral (PI) development, allowing the canonical density be extended for the many-electronic systems through the density functional closure relationship. Yet, the use of path integral formalism for electronic density prescription presents several advantages: assures the inner quantum mechanical description of the system by parameterized paths; averages the quantum fluctuations; behaves as the propagator for time-space evolution of quantum information; resembles Schrödinger equation; allows quantum statistical description of the system through partition function computing. In this framework, four levels of path integral formalism were presented: the Feynman quantum mechanical, the semiclassical, the Feynman-Kleinert effective classical, and the Fokker-Planck non-equilibrium ones. In each case the density matrix or/and the canonical density were rigorously defined and presented. The practical specializations for quantum free and harmonic motions, for statistical high and low temperature limits, the smearing justification for the Bohr's quantum stability postulate with the paradigmatic Hydrogen atomic excursion, along the quantum chemical calculation of semiclassical electronegativity and hardness, of chemical action and Mulliken electronegativity, as well as by the Markovian generalizations of Becke-Edgecombe electronic focalization functions - all advocate for the reliability of assuming PI formalism of quantum mechanics as a versatile one, suited for analytically and/or computationally modeling of a variety of fundamental physical and chemical reactivity concepts characterizing the (density driving) many-electronic systems.

  2. Path Integrals for Electronic Densities, Reactivity Indices, and Localization Functions in Quantum Systems

    Directory of Open Access Journals (Sweden)

    Mihai V. Putz

    2009-11-01

    Full Text Available The density matrix theory, the ancestor of density functional theory, provides the immediate framework for Path Integral (PI development, allowing the canonical density be extended for the many-electronic systems through the density functional closure relationship. Yet, the use of path integral formalism for electronic density prescription presents several advantages: assures the inner quantum mechanical description of the system by parameterized paths; averages the quantum fluctuations; behaves as the propagator for time-space evolution of quantum information; resembles Schrödinger equation; allows quantum statistical description of the system through partition function computing. In this framework, four levels of path integral formalism were presented: the Feynman quantum mechanical, the semiclassical, the Feynman-Kleinert effective classical, and the Fokker-Planck non-equilibrium ones. In each case the density matrix or/and the canonical density were rigorously defined and presented. The practical specializations for quantum free and harmonic motions, for statistical high and low temperature limits, the smearing justification for the Bohr’s quantum stability postulate with the paradigmatic Hydrogen atomic excursion, along the quantum chemical calculation of semiclassical electronegativity and hardness, of chemical action and Mulliken electronegativity, as well as by the Markovian generalizations of Becke-Edgecombe electronic focalization functions – all advocate for the reliability of assuming PI formalism of quantum mechanics as a versatile one, suited for analytically and/or computationally modeling of a variety of fundamental physical and chemical reactivity concepts characterizing the (density driving many-electronic systems.

  3. Experiments on hydraulically-compensated Compressed Air Energy Storage (CAES) system using large-diameter vertical pipe two-phase flow test facility: test facility and test procedure

    International Nuclear Information System (INIS)

    Ohtsu, Iwao; Murata, Hideo; Kukita, Yutaka; Kumamaru, Hiroshige.

    1996-07-01

    JAERI, the University of Tokyo, the Central Research Institute of Electric Power Industry and Shimizu Corporation jointing performed and experimental study on two-phase flow in the hydraulically-compensated Compressed Air Energy Storage (CAES) system with a large-diameter vertical pipe two-phase flow test facility from 1993 to 1995. A hydraulically-compensated CAES system is a proposed, conceptual energy storage system where energy is stored in the form of compressed air in an underground cavern which is sealed by a deep (several hundred meters) water shaft. The shaft water head maintains a constant pressure in the cavern, of several mega Pascals, even during loading or unloading of the cavern with air. The dissolved air in the water, however, may create voids in the shaft when the water rises through the shaft during the loading, being forced by the air flow into the cavern. The voids may reduce the effective head of the shaft, and thus the seal may fail, if significant bubbling should occur in the shaft. This bubbling phenomenon (termed 'Champaign effect') and potential failure of the water seal ('blowout') are simulated in a scaled-height, scaled-diameter facility. Carbon dioxide is used to simulate high solubility of air in the full-height, full-pressure system. This report describes the expected and potential two-phase flow phenomena in a hydraulically-compensated CAES system, the test facility and the test procedure, a method to estimate quantities which are not directly measured by using measured quantities and hydrodynamic basic equations, and desirable additional instrumentation. (author)

  4. Sensitization to reactive diluents and hardeners in epoxy resin systems. IVDK data 2002-2011. Part II: concomitant reactions.

    Science.gov (United States)

    Geier, Johannes; Lessmann, Holger; Hillen, Uwe; Skudlik, Christoph; Jappe, Uta

    2016-02-01

    Beside the basic resins, reactive diluents and hardeners are important sensitizers in epoxy resin systems (ERSs). Because of chemical similarities, immunological cross-reactivity may occur. To analyse concomitant reactivity among reactive diluents and hardeners in the patients concerned, as one integral part of a research project on the sensitizing capacity of ERSs (FP-0324). A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2002-2011, was performed. There was close concomitant reactivity to 1,6-hexanediol diglycidyl ether and 1,4-butanediol diglycidyl ether (1,4-BDDGE), and to phenyl glycidyl ether (PGE) and cresyl glycidyl ether (CGE), whereas reactions to p-tert-butylphenyl glycidyl ether occurred more independently from those to PGE and CGE. Concomitant reactions to butyl glycidyl ether and 1,4-BDDGE may point to a common allergenic compound derived from the metabolism of 1,4-BDDGE. Among the structurally more diverse group of hardeners, there was no evidence of immunological cross-reactions. More detailed knowledge of cross-reactivity among ERS components facilitates the interpretation of patch test results and will allow safer ERSs to be composed in the future. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Sensory reactivity, empathizing and systemizing in autism spectrum conditions and sensory processing disorder.

    Science.gov (United States)

    Tavassoli, Teresa; Miller, Lucy Jane; Schoen, Sarah A; Jo Brout, Jennifer; Sullivan, Jillian; Baron-Cohen, Simon

    2017-05-18

    Although the DSM-5 added sensory symptoms as a criterion for ASC, there is a group of children who display sensory symptoms but do not have ASC; children with sensory processing disorder (SPD). To be able to differentiate these two disorders, our aim was to evaluate whether children with ASC show more sensory symptomatology and/or different cognitive styles in empathy and systemizing compared to children with SPD and typically developing (TD) children. The study included 210 participants: 68 children with ASC, 79 with SPD and 63 TD children. The Sensory Processing Scale Inventory was used to measure sensory symptoms, the Autism Spectrum Quotient (AQ) to measure autistic traits, and the Empathy Quotient (EQ) and Systemizing Quotient (SQ) to measure cognitive styles. Across groups, a greater sensory symptomatology was associated with lower empathy. Further, both the ASC and SPD groups showed more sensory symptoms than TD children. Children with ASC and SPD only differed on sensory under-reactivity. The ASD group did, however, show lower empathy and higher systemizing scores than the SPD group. Together, this suggest that sensory symptoms alone may not be adequate to differentiate children with ASC and SPD but that cognitive style measures could be used for differential diagnosis. Copyright © 2017. Published by Elsevier Ltd.

  6. High rate reactive sputtering in an opposed cathode closed-field unbalanced magnetron sputtering system

    Science.gov (United States)

    Sproul, William D.; Rudnik, Paul J.; Graham, Michael E.; Rohde, Suzanne L.

    1990-01-01

    Attention is given to an opposed cathode sputtering system constructed with the ability to coat parts with a size up to 15 cm in diameter and 30 cm in length. Initial trials with this system revealed very low substrate bias currents. When the AlNiCo magnets in the two opposed cathodes were arranged in a mirrored configuration, the plasma density at the substrate was low, and the substrate bias current density was less than 1 mA/sq cm. If the magnets were arranged in a closed-field configuration where the field lines from one set of magnets were coupled with the other set, the substrate bias current density was as high as 5.7 mA/sq cm when NdFeB magnets were used. In the closed-field configuration, the substrate bias current density was related to the magnetic field strength between the two cathodes and to the sputtering pressure. Hard well-adhered TiN coatings were reactively sputtered in the opposed cathode system in the closed-field configuration, but the mirrored configuration produced films with poor adhesion because of etching problems and low plasma density at the substrate.

  7. Development of a Voltage Compensation Type Active SFCL and Its Application for Transient Performance Enhancement of a PMSG-Based Wind Turbine System

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2017-01-01

    Full Text Available Considering the rapid development of high temperature superconducting (HTS materials, superconducting power applications have attracted more and more attention in the power industry, particularly for electrical systems including renewable energy. This paper conducts experimental tests on a voltage compensation type active superconducting fault current limiter (SFCL prototype and explores the SFCL’s application in a permanent-magnet synchronous generator- (PMSG- based wind turbine system. The SFCL prototype is composed of a three-phase air-core superconducting transformer and a voltage source converter (VSC integrated with supercapacitor energy storage. According to the commissioning test and the current-limiting test, the SFCL prototype can automatically suppress the fault current and offer a highly controlled compensation voltage in series with the 132 V electrical test system. To expand the application of the active SFCL in a 10 kW class PMSG-based wind turbine system, digital simulations under different fault cases are performed in MATLAB/Simulink. From the demonstrated simulation results, using the active SFCL can help to maintain the power balance, mitigate the voltage-current fluctuation, and improve the wind energy efficiency. The active SFCL can be regarded as a feasible solution to assist the PMSG-based wind turbine system to achieve low-voltage ride-through (LVRT operation.

  8. Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

    International Nuclear Information System (INIS)

    Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-01-01

    Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities to simulate) impacts of coupled processes on radionuclide transport in different components of EBS, as well as the interaction between near-field host rock (e.g., clay) and EBS and how they effect radionuclide release. This final report documents the progress that LBNL has made in its focus areas. Specifically, Section 2 summarizes progress on literature review for THMC processes and reactive-diffusive radionuclide transport in bentonite. The literature review provides a picture of the state-of-the-art of the relevant research areas

  9. Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

    Energy Technology Data Exchange (ETDEWEB)

    Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities to simulate) impacts of coupled processes on radionuclide transport in different components of EBS, as well as the interaction between near-field host rock (e.g., clay) and EBS and how they effect radionuclide release. This final report documents the progress that LBNL has made in its focus areas. Specifically, Section 2 summarizes progress on literature review for THMC processes and reactive-diffusive radionuclide transport in bentonite. The literature review provides a picture of the state-of-the-art of the relevant research areas

  10. Numerical modeling of coupled thermal chemical reactive transport: simulation of a heat storage system

    Science.gov (United States)

    Shao, H.; Watanabe, N.; Singh, A. K.; Nagel, T.; Linder, M.; Woerner, A.; Kolditz, O.

    2012-12-01

    As a carbon-free energy supply technology, the operation time and final energy output of thermal solar power plants can be greatly extended if efficient thermal storage systems are applied. One of the proposed design of such system is to utilize reversible thermochemical reactions and its embedded reaction enthalpy, e.g. the Ca(OH)2/CaO hydration circle, in a fixed-bed gas-solid reactor (Schaube et al. 2011) The modeling of such a storage system involves multiple strongly-coupled physical and chemical processes. Seepage velocity is calculated by the nonlinear Forchheimer law. Gas phase density and viscosity are temperature, pressure and composition dependent. Also, heat transfer between gas and solid phases is largely influenced by the exothermal heat produced by the hydration of calcium oxide. Numerical solution of four governing PDEs include the mass balance, reactive transport, heat balance equations for gas and solid phases, which are implemented into the open source scientific software OpenGeoSys in a monolithic way. Based on it, a 2D numerical model, considering the boundary heat loss of the system, was set up to simulate the energy-storage and release circle. The high performance computing techniques were employed in two stages. First, the dynamic behavior of the heat storage system is simulated on a parallel platform. Second, a large number of processors are employed to perform sensitivity analysis, whereas the reaction rates and efficiency factor of heat transfer are parameterized so that the measured and simulated temperature profile fit with each other. The model showed that heat transfer coefficient between solid and gas phase, grain size of the filling material will influence the final performance greatly. By varying these factors, the calibrated model will be further applied to optimize the design of such energy storage system.

  11. Thermally tunable dispersion compensator in 40-Gb/s system using FBG fabricated with linearly chirped phase mask.

    Science.gov (United States)

    Sun, Jie; Dai, Yitang; Chen, Xiangfei; Zhang, Yejin; Xie, Shizhong

    2006-01-09

    An improved design and fabrication method of nonlinearly chirped fiber Bragg gratings is demonstrated. Based on reconstruction-equivalent- chirp method, the nonlinearly chirped fiber Bragg grating is realized with a linearly chirped phase mask instead of a uniform one, which improves the performance of the device. Coated with uniform thin metal film, the obtained grating works as a tunable dispersion compensator with a tuning range ~200ps/nm, peak-to-peak group delay ripple fiber using carrier suppressed return-to-zero format is less than 0.7dB at a BER=10-10.

  12. Chemical Imaging and Dynamical Studies of Reactivity and Emergent Behavior in Complex Interfacial Systems. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Sibener, Steven J. [Univ. of Chicago, IL (United States). James Franck Inst. and Dept. of Chemistry

    2014-03-11

    This research program explored the efficacy of using molecular-level manipulation, imaging and scanning tunneling spectroscopy in conjunction with supersonic molecular beam gas-surface scattering to significantly enhance our understanding of chemical processes occurring on well-characterized interfaces. One program focus was on the spatially-resolved emergent behavior of complex reaction systems as a function of the local geometry and density of adsorbate-substrate systems under reaction conditions. Another focus was on elucidating the emergent electronic and related reactivity characteristics of intentionally constructed single and multicomponent atom- and nanoparticle-based materials. We also examined emergent chirality and self-organization in adsorbed molecular systems where collective interactions between adsorbates and the supporting interface lead to spatial symmetry breaking. In many of these studies we combined the advantages of scanning tunneling (STM) and atomic force (AFM) imaging, scanning tunneling local electronic spectroscopy (STS), and reactive supersonic molecular beams to elucidate precise details of interfacial reactivity that had not been observed by more traditional surface science methods. Using these methods, it was possible to examine, for example, the differential reactivity of molecules adsorbed at different bonding sites in conjunction with how reactivity is modified by the local configuration of nearby adsorbates. At the core of this effort was the goal of significantly extending our understanding of interfacial atomic-scale interactions to create, with intent, molecular assemblies and materials with advanced chemical and physical properties. This ambitious program addressed several key topics in DOE Grand Challenge Science, including emergent chemical and physical properties in condensed phase systems, novel uses of chemical imaging, and the development of advanced reactivity concepts in combustion and catalysis including carbon

  13. NADPH oxidase(s): new source(s) of reactive oxygen species in the vascular system?

    NARCIS (Netherlands)

    van Heerebeek, L.; Meischl, C.; Stooker, W.; Meijer, C. J. L. M.; Niessen, H. W. M.; Roos, D.

    2002-01-01

    Reactive oxygen species play an important role in a variety of (patho)physiological vascular processes. Recent publications have produced evidence of a role for putative non-phagocyte NADP oxidase(s) in the vascular production of reactive oxygen species. In the present review, we discuss the

  14. The epigenetic landscape related to reactive oxygen species formation in the cardiovascular system.

    Science.gov (United States)

    Kietzmann, Thomas; Petry, Andreas; Shvetsova, Antonina; Gerhold, Joachim M; Görlach, Agnes

    2017-06-01

    Cardiovascular diseases are among the leading causes of death worldwide. Reactive oxygen species (ROS) can act as damaging molecules but also represent central hubs in cellular signalling networks. Increasing evidence indicates that ROS play an important role in the pathogenesis of cardiovascular diseases, although the underlying mechanisms and consequences of pathophysiologically elevated ROS in the cardiovascular system are still not completely resolved. More recently, alterations of the epigenetic landscape, which can affect DNA methylation, post-translational histone modifications, ATP-dependent alterations to chromatin and non-coding RNA transcripts, have been considered to be of increasing importance in the pathogenesis of cardiovascular diseases. While it has long been accepted that epigenetic changes are imprinted during development or even inherited and are not changed after reaching the lineage-specific expression profile, it becomes more and more clear that epigenetic modifications are highly dynamic. Thus, they might provide an important link between the actions of ROS and cardiovascular diseases. This review will provide an overview of the role of ROS in modulating the epigenetic landscape in the context of the cardiovascular system. This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc. © 2017 The British Pharmacological Society.

  15. Immune System Dysregulation and Latent Herpesvirus Reactivation During Winterover at Concordia Station, Dome C, Antarctica

    Science.gov (United States)

    Crucian, B. E.; Feuerecker, M.; Salam, A. P.; Rybka, A.; Stowe, R. P.; Morrels, M.; Meta, S. K.; Quiriarte, H.; Quintens, Roel; Thieme, U.; hide

    2011-01-01

    Immune system dysregulation occurs during spaceflight and consists of altered peripheral leukocyte distribution, reductions in immunocyte function and altered cytokine production profiles. Causes may include stress, confinement, isolation, and disrupted circadian rhythms. All of these factors may be replicated to some degree in terrestrial environments. NASA is currently evaluating the potential for a ground-based analog for immune dysregulation, which would have utility for mechanistic investigations and countermeasures evaluation. For ground-based space physiology research, the choice of terrestrial analog must carefully match the system of interest. Antarctica winter-over, consisting of prolonged durations in an extreme/dangerous environment, station-based habitation, isolation and disrupted circadian rhythms, is potentially a good ground-analog for spaceflight-associated immune dysregulation. Of all Antarctica bases, the French-Italian Concordia Station, may be the most appropriate to replicate spaceflight/exploration conditions. Concordia is an interior base located in harsh environmental conditions, and has been constructed to house small, international crews in a station-environment similar to what should be experienced by deep space astronauts. The ESA-NASA CHOICE study assessed innate and adaptive immunity, viral reactivation and stress factors during Concordia winterover deployment. The study was conducted over two winterover missions in 2009 and 2010. Final study data from NASA participation in these missions will be presented.

  16. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  17. Heading Estimation with Real-time Compensation Based on Kalman Filter Algorithm for an Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Xin Li

    2016-06-01

    Full Text Available The problem of heading drift error using only low cost Micro-Electro-Mechanical (MEMS Inertial-Measurement-Unit (IMU has not been well solved. In this paper, a heading estimation method with real-time compensation based on Kalman filter has been proposed, abbreviated as KHD. For the KHD method, a unified heading error model is established for various predictable errors in magnetic compass for pedestrian navigation, and an effective method for solving the model parameters is proposed in the indoor environment with regular structure. In addition, error model parameters are solved by Kalman filtering algorithm with building geometry information in order to achieve real-time heading compensation. The experimental results show that the KHD method can not only effectively correct the original heading information, but also effectively inhibit the accumulation effect of positioning errors. The performance observed in a field experiment performed on the fourth floor of the School of Environmental Science and Spatial Informatics (SESSI building on the China University of Mining and Technology (CUMT campus confirms that apply KHD method to PDR(Pedestrian Dead Reckoning algorithm can reliably achieve meter-level positioning using a low cost MEMS IMU only.

  18. stability analysis of a three-phase solid-state var compensator

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. The problems associated with the flow of reactive power in transmission and distribution lines are well known. Several methods of var compensation have been applied in solving these problems. One of the modern devices employed in reactive power compensation is the three-phase solid-state.

  19. Microglia - insights into immune system structure, function, and reactivity in the central nervous system

    DEFF Research Database (Denmark)

    Wirenfeldt, Martin; Babcock, Alicia A; Vinters, Harry V

    2011-01-01

    Microglia are essential cellular components of a well-functioning central nervous system (CNS). The development and establishment of the microglial population differs from the other major cell populations in the CNS i.e. neurons and macroglia (astrocytes and oligodendrocytes). This different...

  20. Reactive Power based Model Reference Neural Learning Adaptive System for Speed Estimation in Sensor-less Induction Motor Drives

    Directory of Open Access Journals (Sweden)

    K Sedhuraman

    2012-12-01

    Full Text Available In this paper, a novel reactive power based model reference neural learning adaptive system (RP-MRNLAS is proposed. The model reference adaptive system (MRAS based speed estimation is one of the most popular methods used for sensor-less controlled induction motor drives. In conventional MRAS, the error adaptation is done using a Proportional-integral-(PI. The non-linear mapping capability of a neural network (NN and the powerful learning algorithms have increased the applications of NN in power electronics and drives. Thus, a neural learning algorithm is used for the adaptation mechanism in MRAS and is often referred to as a model reference neural learning adaptive system (MRNLAS. In MRNLAS, the error between the reference and neural learning adaptive models is back propagated to adjust the weights of the neural network for rotor speed estimation. The two different methods of MRNLAS are flux based (RF-MRNLAS and reactive power based (RP-MRNLAS. The reactive power- based methods are simple and free from integral equations as compared to flux based methods. The advantage of the reactive power based method and the NN learning algorithms are exploited in this work to yield a RPMRNLAS. The performance of the proposed RP-MRNLAS is analyzed extensively. The proposed RP-MRNLAS is compared in terms of accuracy and integrator drift problems with popular rotor flux-based MRNLAS for the same system and validated through Matlab/Simulink. The superiority of the RP- MRNLAS technique is demonstrated