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Sample records for ac transmission systems

  1. Flexible AC transmission systems modelling and control

    Zhang, Xiao-Ping; Pal, Bikash

    2012-01-01

    The extended and revised second edition of this successful monograph presents advanced modeling, analysis and control techniques of Flexible AC Transmission Systems (FACTS). The book covers comprehensively a range of power-system control problems: from steady-state voltage and power flow control, to voltage and reactive power control, to voltage stability control, to small signal stability control using FACTS controllers. In the six years since the first edition of the book has been published research on the FACTS has continued to flourish while renewable energy has developed into a mature and

  2. Flexible AC transmission systems: the state of the art

    Edris, Abdel-Aty [Electric Power Research Inst., Palo Alto, CA (United States). Electric Systems Division

    1994-12-31

    Flexible AC transmission systems (FACTS) is a concept promoting the use of power electronic controllers to enhance the controllability and usable capacity of AC transmission. This paper presents the state of the art of FACTS and the status of the current projects for the application of the FACTS controllers in transmission systems. (author) 8 refs., 8 figs.

  3. Flexible AC transmission system devices: allocation and transmission pricing

    The transmission of electricity differs from transportation of any typical commodity by some inherent aspects such as: the production needs to match the consumption at the same time; system control is not an easy task; the electricity flows do not usually follow the economic law. The last aspect is normally observed when transmission systems are included in, for instance, an economic dispatch problem. One way to minimize the operational costs caused by an overloaded transmission system is through the installation of Flexible AC Transmission System (FACTS) devices in the system. They are able to change power flows by modifying the network parameters. This paper focuses on the ability of FACTS devices to change the overall costs of the system and their impact on transmission pricing. The allocation and the determination of the FACTS required are also discussed. Some examples using the IEEE-14 system and the Brazilian electrical system of the Southern region are given to illustrate the concepts introduced in this paper. (author)

  4. Guiding Principles in Selecting AC To DC Converters For Power Factor Corrections in AC Transmission System

    Ibekwe B.E

    2014-10-01

    Full Text Available The ac to dc converters’ power factors correction in ac transmission system were investigated. The studies include: phase-controlled converter; pulse width modulated (PWM converter and ac input current shaped converter. Using Fourier series, power factors of these converters were calculated and simulated using MATLAB. The resulting curves are displayed in the hard copies for practical guides in the choice of converters; and comparatively, current shaped type is the best.

  5. Voltage Swell Mitigation Using Flexible AC Transmission Systems Based on Evolutionary Computing Methods

    Marwa Shahin; Ebtisam Saied; M.A. Moustafa Hassan; Fahmy Bendary

    2014-01-01

    The main subject of these paper deals with enhancing the steady-state and dynamics performance of the power grids by using new idea namely Advanced Flexible AC Transmission Systems based on Evolutionary Computing Methods. Control of the electric power system can be achieved by using the new trends as Particle Swarm Optimization applied to this subject to enhance the characteristics of controller performance. This paper studies and analyzes Advanced Flexible AC Transmission System to mitigate ...

  6. Combination of AC Transmission Expansion Planning and Reactive Power Planning in the restructured power system

    Highlights: ► To overcome the disadvantages of DC model in Transmission Expansion Planning, AC model should be used. ► The Transmission Expansion Planning associated with Reactive Power Planning results in fewer new transmission lines. ► Electricity market concepts should be considered in Transmission Expansion Planning problem. ► Reliability aspects should be considered in Transmission Expansion Planning problem. ► Particle Swarm Optimization is a suitable optimization method to solve Transmission Expansion Planning problem. - Abstract: Transmission Expansion Planning (TEP) is an important issue in power system studies. It involves decisions on location and number of new transmission lines. Before deregulation of the power system, the goal of TEP problem was investment cost minimization. But in the restructured power system, nodal prices, congestion management, congestion surplus and so on, have been considered too. In this paper, an AC model of TEP problem (AC-TEP) associated with Reactive Power Planning (RPP) is presented. The goals of the proposed planning problem are to minimize investment cost and maximize social benefit at the same time. In the proposed planning problem, in order to improve the reliability of the system the Expected Energy Not Supplied (EENS) index of the system is limited by a constraint. For this purpose, Monte Carlo simulation method is used to determine the EENS. Particle Swarm Optimization (PSO) method is used to solve the proposed planning problem which is a nonlinear mixed integer optimization problem. Simulation results on Garver and RTS systems verify the effectiveness of the proposed planning problem for reduction of the total investment cost, EENS index and also increasing social welfare of the system.

  7. Scalable Heuristics for Planning, Placement and Sizing of Flexible AC Transmission System Devices

    Frolov, Vladmir [Skolkovo Institute of Science and Technology, Skolkovo (Russia); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-02

    Aiming to relieve transmission grid congestion and improve or extend feasibility domain of the operations, we build optimization heuristics, generalizing standard AC Optimal Power Flow (OPF), for placement and sizing of Flexible Alternating Current Transmission System (FACTS) devices of the Series Compensation (SC) and Static VAR Compensation (SVC) type. One use of these devices is in resolving the case when the AC OPF solution does not exist because of congestion. Another application is developing a long-term investment strategy for placement and sizing of the SC and SVC devices to reduce operational cost and improve power system operation. SC and SVC devices are represented by modification of the transmission line inductances and reactive power nodal corrections respectively. We find one placement and sizing of FACTs devices for multiple scenarios and optimal settings for each scenario simultaneously. Our solution of the nonlinear and nonconvex generalized AC-OPF consists of building a convergent sequence of convex optimizations containing only linear constraints and shows good computational scaling to larger systems. The approach is illustrated on single- and multi-scenario examples of the Matpower case-30 model.

  8. High power switch mode linear amplifiers for flexible ac transmission system

    Mwinyiwiwa, B.; Wolanski, Z.; Ooi, B.T. [McGill Univ., Montreal, Quebec (Canada). Dept. of Electrical Engineering

    1996-10-01

    The Pulse Width Modulation (PWM) technique has been proposed for the force-commutated Shunt and Series VAR Controllers and Unified Power Flow Controllers in Flexible AC Transmission Systems. The PWM converters can be operated as linear amplifiers of constant gain so that treasure trove of linear control system theory can be brought to bear more easily when applying feedback controls. For example, pole-placement and active filtering have been successfully applied in laboratory models. This paper is written as a tutorial describing the stages of signal processing: modulation, amplification and demodulation, without reference to power electronics since the solid-state switches are modelled as ON-OFF switches.

  9. A Secondary Voltage Control Method for an AC/DC Coupled Transmission System Based on Model Predictive Control

    Xu, Fengda; Guo, Qinglai; Sun, Hongbin;

    2015-01-01

    For an AC/DC coupled transmission system, the change of transmission power on the DC lines will significantly influence the AC systems’ voltage. This paper describes a method to coordinated control the reactive power of power plants and shunt capacitors at DC converter stations nearby, in order to...... keep the voltage of the pilot bus tracking its set point considering the DC system’s transmission schedule change. The approach is inspired by model predictive control (MPC) to compensate for predictable voltage change affected by DC side transmission power flow and the potential capacitor switching at...

  10. Enhancing power transfer capability through flexible AC transmission system devices:a review

    Fadi M ALBATSH; Saad MEKHILEF; Shameem AHMAD; H MOKHLIS; M A HASSAN

    2015-01-01

    Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system (FACTS) devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the avail-able transfer capability (ATC) and power transfer capability (PTC) of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC im-provement with respect to different control algorithms.

  11. Application of Multi-Objective Evolutionary Algorithm for Optimal Reactive Power Dispatch with Flexible AC Transmission System Devices

    Abdarrazak OUALI; Hsan HADJ ABDALLAH; Tawfik GUESMI; Ismail MAROUANI

    2011-01-01

    Because their capability to change the network parameters with a rapid response and enhanced flexibility, flexible AC transmission system (FACTS) devices have taken more attention in power systems operations as improvement of voltage profile and minimizing system losses. In this way, this paper presents a multi-objective evolutionary algorithm (MOEA) to solve optimal reactive power dispatch (ORPD) problem with FACTS devices. This nonlinear multi-objective problem (MOP) consists to minimize si...

  12. Ranking transmission projects in large scale systems using an AC power flow model; Priorizacao de obras em sistemas de grande porte usando um modelo AC da rede

    Melo, A.C.G. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Fontoura Filho, R.N. [ELETROBRAS, Rio de Janeiro, RJ (Brazil); Peres, L.A.P. Pecorelli [FURNAS, Rio de Janeiro, RJ (Brazil); Morozowski Filho, M. [Santa Catarina Univ., Florianopolis, SC (Brazil)

    1994-12-31

    Initially, this paper summarizes the approach developed by the Brazilian Planning Criteria Working Group (GTCP/ELETROBRAS) for identifying which subset of transmission investments should be postponed to meet a pre-stablished budget constraint with the least possible impact on system performance. Next, this paper presents the main features of the computational model PRIO, which allows the application of the ranking process to large scale power systems (2,000 buses and 3,000 circuits), with as many as 100 projects to be ranked. In this model, the adequacy analysis of each system state is carried out through an AC power flow coupled to a successive linear programming based remedial actions model. Case studies with the IEEE-RTS system and a configuration of the Brazilian Southeastern are presented and discussed. (author) 7 refs., 6 figs., 5 tabs.

  13. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  14. Application of Multi-Objective Evolutionary Algorithm for Optimal Reactive Power Dispatch with Flexible AC Transmission System Devices

    Abdarrazak OUALI

    2011-12-01

    Full Text Available Because their capability to change the network parameters with a rapid response and enhanced flexibility, flexible AC transmission system (FACTS devices have taken more attention in power systems operations as improvement of voltage profile and minimizing system losses. In this way, this paper presents a multi-objective evolutionary algorithm (MOEA to solve optimal reactive power dispatch (ORPD problem with FACTS devices. This nonlinear multi-objective problem (MOP consists to minimize simultaneously real power loss in transmission lines and voltage deviation at load buses, by tuning parameters and searching the location of FACTS devices. The constraints of this MOP are divided to equality constraints represented by load flow equations and inequality constraints such as, generation reactive power sources and security limits at load buses. Two types of FACTS devices, static synchronous series compensator (SSSC and unified power flow controller (UPFC are considered. A comparative study regarding the effects of an SSSC and an UPFC on voltage deviation and total transmission real losses is carried out. The design problem is tested on a 6-bus system.

  15. Online Location of Faults on AC Cables in Underground Transmission Systems

    Jensen, Christian Flytkjær

    2013-01-01

    A transmission grid is normally laid out as an almost pure overhead line (OHL) network. The introduction of transmission voltage level XLPE cables and the increasing interest in the environmental impact of OHL has resulted in an increasing interest in the use of underground cables on transmission level. In Denmark for instance, the entire 150 kV, 132 kV and 220 kV and parts of the 400 kV transmission network will be placed underground before 2030.To reduce the operating losses of a cable-base...

  16. Offshore windfarm connection with low frequency AC transmission technology

    Qin, Nan; Xu, Zhao; You, Shi;

    2009-01-01

    This paper investigates the feasibility of using the low frequency AC transmission (LFAC) system, e.g. fraction of 50 Hz or 60 Hz, for connecting the large offshore wind farm to the grid by modelling and simulation. The LFAC system improves the transmission capacity and distance compared to the c...

  17. Modelling of long High Voltage AC Cables in the Transmission System

    Gudmundsdottir, Unnur Stella

    for comparison at the measuring site. Measurements are performed on a 400 kV 7.6 km long cable, which is a part of a hybrid OHL/cable transmission line. The cables are laid in flat formation and have been in operation for several years. For performing the measurements, the cables are disconnected from...... time. From analysing the modal currents, the source of deviation is identified. The same phenomena and source for deviation between field measurements and simulation results is identified for a 400 kV flat formation crossbonded 7.6 km cable line, a 150 kV tight trefoil crossbonded 2.5 km cable line and...... a way, that the impedance matrix is no longer calculated from the analytical equations but from a finite element method including the proximity effect. A MATLAB program is constructed in order to calculate the impedance matrix based on the finite element method. Furthermore, this MATLAB program also...

  18. Online fault location on crossbonded AC cables in underground transmission systems

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    of a 245 kV crossbonded cable system, connecting the newly installed 400 MW Danish offshore wind farm Anholt to the main grid, are obtained and used to verify the proposed system. Furthermore, extensive simulation data created in PSCAD/EMTDC is used in order to examine the robustness of the system to......In this paper, a fault locator system specifically designed for crossbonded cables is described. Electromagnetic wave propagation theory for crossbonded cables with focus on fault location purposes is discussed. Based on this, the most optimal modal component and input signal to the fault locator...... system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in the substations by two fault locator units. Field measurements of faults artificially created on a section...

  19. Online fault location on crossbonded AC cables in underground transmission systems

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    In this paper, a fault locator system specifically designed for crossbonded cables is described. Electromagnetic wave propagation theory for crossbonded cables with focus on fault location purposes is discussed. Based on this, the most optimal modal component and input signal to the fault locator system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in th...

  20. Online Fault Location on AC Cables in Underground Transmission Systems using Sheath Currents

    Jensen, Christian Flytkjær; Nanayakkarab, Kasun; Rajapakse, Athula;

    2014-01-01

    This paper studies online travelling wave methods for fault location on a crossbonded cable system using sheath currents. During the construction of the electrical connection to the 400 MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4 km crossbonded cable system. At...

  1. Online fault location on AC cables in underground transmission systems using screen currents

    Jensen, Christian Flytkjær; Nanayakkara, O.M.K.K; Rajapakse, Athula;

    This paper studies online travelling wave methods for fault location on a crossbonded cable system using screen currents. During the construction of the electrical connection to the 400 MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4 km crossbonded cable system. At...... coils if the screen currents contain the necessary information for accurate fault location. In this paper, this is examined by analysis of field measurements and through a study of simulations. The wavelet transform and visual inspection methods are used and the accuracy is compared. Field measurements...

  2. Online Location of Faults on AC Cables in Underground Transmission Systems

    Jensen, Christian Flytkjær

    deviations in the parameters of the OHL will result in large errors for fault location in the cable section. Field measurements showing the effect of short circuits on crossbonded systems conducted on parts of the electrical connection to the Anholt offshore wind farm are performed. The purpose is to examine...... whether neural networks can be trained using data from state-of-theart cable models to predict and estimate the fault location on crossbonded cables. Numerous measurements of different short circuits are carried out and it is concluded that the state-ofthe-art models predict general behaviour of the...... crossbonded system under fault conditions well, but the accuracy of the calculated impedance is low for fault location purposes. The neural networks can therefore not be trained and no impedance-based fault location method can be used for crossbonded cables or hybrid lines. The use of travelling wave...

  3. Composite Based EHV AC Overhead Transmission Lines

    Sørensen, Thomas Kjærsgaard

    Overhead lines at transmission level are the backbone of any national power grid today. New overhead line projects however are at the same time subject to ever greater public resistance due to the lines environmental impact. As full undergrounding of transmission lines at extra high voltage (EHV......) levels are still not seen as possibility, the future expansion of transmission grids are dependent on new solutions with lessened environment impact, especially with regard to the visual impact. In the present Thesis, composite materials and composite based overhead line components are presented and...... analysed with regard to the possibilities, limitations and risks widespread application of composite materials on EHV AC overhead transmission lines may present. To form the basis for evaluation of the useability of composite materials, dierent overhead line projects aimed at reducing the environmental...

  4. Analysis of Reactive Power Compensation in UHV AC Transmission System%特高压交流输电系统无功补偿策略分析

    李静雅

    2015-01-01

    Ultra high voltage transmission system with a high rechargeable power,long transmission line characteris-tics,and thus faces a serious problem of reactive power balance,in order to ensure the effect of reactive power compensa-tion in UHV transmission system,analyzed the reactive power compensation strategy in UHV AC transmission system in this paper.%特高压输电系统具有充电功率大,输电线路长的特点,但面临严重的无功平衡问题。为了保证特高压输电系统的无功补偿效果,文中分析了特高压交流输电系统无功补偿策略。

  5. Analysis of Reactive Power Compensation in UHV AC Transmission System%特高压交流输电系统无功补偿策略分析

    李静雅

    2015-01-01

    特高压输电系统具有充电功率大,输电线路长的特点,但面临严重的无功平衡问题。为了保证特高压输电系统的无功补偿效果,文中分析了特高压交流输电系统无功补偿策略。%Ultra high voltage transmission system with a high rechargeable power,long transmission line characteris-tics,and thus faces a serious problem of reactive power balance,in order to ensure the effect of reactive power compensa-tion in UHV transmission system,analyzed the reactive power compensation strategy in UHV AC transmission system in this paper.

  6. Evaluating conversion of AC power transmission lines to DC

    Edris, A. [EPRI, Palo Alto, CA (United States); Barthold, L. [IMod Inc., Lafayette, LA (United States); Douglass, D. [Power Delivery Consultants, Ballston Lake, NY (United States); Litzenberger, W. [Litzenberger Consultant (United States); Woodford, D. [Electranix, Winnipeg, MB (Canada)

    2008-07-01

    Conversion of alternating current (AC) transmission lines has been of significant interest for several years but has never been implemented to expand transmission line capacity or improve system security. This paper outlined the procedures necessary to identify and assess feasibility of specific AC to direct current (DC) conversion opportunities, with special focus on emerging DC transmission technologies. The paper outlined the process for investigating the conversion of an AC transmission line to DC. The investigation examined both bipole and tripole applications. A summary of the characteristics for alternative DC conversion configuration was presented. These characteristics included maximum transfer capability; redundancy; losses; overhead ratio; switching requirements; reactive power requirement; and accommodation of taps. The challenges and objectives of the project were also described. The paper provided a summary of the cost and benefit analysis for the various AC to DC conversion technologies for the Grand Coulee to Olympia transmission line. It was concluded that the project was particularly timely in that current work on the prospect of major North American system segmentation could benefit substantially, both technically and economically by having inter-system links take fuller advantage of the inherent DC capability of the circuits involved, thereby encouraging greater inter-regional energy exchange and providing the basis for lower energy supply costs. 12 refs., 2 tabs., 3 figs., 1 appendix.

  7. AC power supply systems

    An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

  8. Identification of problems when using long high voltage AC cable in transmission system I: Switching transient problems

    Rahimi, Saeed; Wiechowski, W.; Randrup, M;

    2008-01-01

    the proper substitution and solution which make the transmission expansion possible with minimized visual impacts on the communities. Within European countries, Denmark was been at the forefront of replacing the transmission lines with cables. The project was supplying the power to the greater......Due to political and environmental pressures from the public and government side, upgrading and building new transmission facilities are becoming more and more difficult and in some cases the expansion of overhead transmission lines are impossible. This means that underground cable technology is...

  9. UHV A.C. transmission: Technology and prospects

    At the beginning of the 70's, UHV transmission was regarded as imminent in many countries in view of the expected concentration of generating units (possibly of the nuclear type and grouped together in a few large plants, each of several GW), and research projects were therefore launched in the U.S.A., Canada, Italy, Japan, USSR, etc. Nowadays, the expected introduction of UHV transmission seems remote due to the slowdown in electricity growth and to the tendency towards distributed generation. Nevertheless, there are exceptions: the 1,200 kV 2,400 km-long transmission system in operation in Siberia-Kazahkstan-Urals, and the 1,100 kV 200 km double-circuit line under construction in Japan (which will, however, be operated at 500 kV up to the end of the century). In addition, in Italy, the research programme of a 1000 kV project has now been completed and a 1,050 kV pilot plant is under construction in Tuscany, consisting of a short 1,050kV line and a 420/1,050 kV 1,200 MVA substation. The technology of UHV AC transmission has therefore been proved effective and may represent an available option for the power systems of the next century. From the power system planning point-of-view, UHV's favourable characteristics lie in the possibility of transmitting large amount of power, of the order of 5 GW per circuit, with lower costs, reduced losses, and less land occupation than in the case of EHV lines

  10. A Research Review on the Transmission System of AC Servo Motor Direct Drive Hydraulic Press%交流伺服电机直驱液压机传动系统研究综述

    范淑琴; 赵升吨; 陈超; 杨建辉

    2015-01-01

    交流伺服电机直驱液压机相比传统液压机,具有低速锻冲、快速空程向下及快速回程的特点,其交流伺服电机直驱的传动方式可有效减少滑块上行和下行的时间,大大提高液压机工作速度。介绍了国内外交流伺服电机直驱液压机传动系统的研究现状,提出了一种无油泵交流伺服电机直驱新型液压机传动方式,介绍了该新型液压机传动系统的构成及工作原理,并提出了研制该无油泵交流伺服电机直驱新型液压机所需要解决的科学问题。%Compared to the traditional hydraulic press, Ac servo motor direct drive hydraulic press has the characteris-tics including rapid falling, slow forging and fast return. The transmission mode of AC servo motor direct drive can effec-tively reduce both the falling time and rising time of the slider, and greatly improve the working speed of hydraulic press. The research status of transmission system of Ac servo motor direct drive hydraulic press are introduced in this paper, and the transmission model of a new type AC servo motor direct drive hydraulic press without oil pump is proposed. Both the composition and working principle of the transmission system of the new type hydraulic presser are introduced, and the sci-entific problems about the new type AC servo motor direct drive hydraulic press without oil pump are put forward.

  11. ac propulsion system for an electric vehicle

    Geppert, S.

    1980-01-01

    It is pointed out that dc drives will be the logical choice for current production electric vehicles (EV). However, by the mid-80's, there is a good chance that the price and reliability of suitable high-power semiconductors will allow for a competitive ac system. The driving force behind the ac approach is the induction motor, which has specific advantages relative to a dc shunt or series traction motor. These advantages would be an important factor in the case of a vehicle for which low maintenance characteristics are of primary importance. A description of an EV ac propulsion system is provided, taking into account the logic controller, the inverter, the motor, and a two-speed transmission-differential-axle assembly. The main barrier to the employment of the considered propulsion system in EV is not any technical problem, but inverter transistor cost.

  12. New Comparison of HVDC and HVAC Transmission system

    Vahid Behravesh

    2012-06-01

    Full Text Available Alternating current (AC is the main driving force in the industries and residential areas, but for the long transmission line (more than 400 miles AC transmission is more expensive than that of direct current (DC. Technically, AC transmission line control is more complicated because of the frequency. DC transmission does not have these limitations, which has led to build long HVDC transmission lines over the last 40 years. HVDC technology made possible to transfer bulk power over long distances. This paper presents a comparative evaluation of HVDC and HVAC transmission systems .

  13. Digital model for harmonic interactions in AC/DC/AC systems

    Guarini, A.P.; Rangel, R.D.; Pilotto, L.A.S.; Pinto, R.J.; Passos Junior, R. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

    1994-12-31

    The main purpose of this paper is to present a model for calculation of HVdc converter harmonics taking into account the influence of the harmonic interactions between the ac systems in dc link transmissions. The ideas and methodologies used in the model development take into account the dc current ripple and ac voltage distortion in the ac systems. The theory of switching functions is applied to contemplate for the frequency conversions between the ac and dc sides, in an iterative process. It is possible then to obtain, even in balanced situations, non-characteristic harmonics that are produced by frequencies originated in the other terminal, which can be significant in a strongly coupled system, such as back-to-back configuration. (author) 9 refs., 3 figs.

  14. Seventy Three SGCC Standards on 1000 kV UHV AC Transmission Technology

    2011-01-01

    Name of Project:73 Standards including Q/GDW 319-2009 1000kV AC Transmission System Overvoltage and Insulation Coordination Guidelines Main Participant Units:State Grid Corporation of China,China Electric Power Research Institute,State Grid Electric Power Research Institute,China Power Engineering Consulting Group Corporation,Communication and Construction Branch of State Grid Corporation,Grid Operation Branch of State Grid Corporation Main Contributors:Liu Zhenya,Shu Yinbiao,Zheng Baosen,Sun Xin,Chen Weijiang,Yu Yongqing,Wang Jianping,Sun Zhusen,Liang Xuming,Guo Jianbo Award Grade:First PrizeBackground Ultra-High Voltage (UHV) transmission is featured by long distance,large capacity,low line loss,and land conservation.Compared with 500 kV EHV transmission system,UHV transmission power can be 4-5 times for the same transmission distance,UHV transmission distance and corridor capacity can be 3 times,but loss of transmission lines can be only one third for the same transmission power.At the end of 2004,State Grid Corporation of China (SGCC) made a proposal to develop the UHV technology and build a strong power grid.

  15. Magnetic Nanoparticle Thermometer: An Investigation of Minimum Error Transmission Path and AC Bias Error

    Zhongzhou Du

    2015-04-01

    Full Text Available The signal transmission module of a magnetic nanoparticle thermometer (MNPT was established in this study to analyze the error sources introduced during the signal flow in the hardware system. The underlying error sources that significantly affected the precision of the MNPT were determined through mathematical modeling and simulation. A transfer module path with the minimum error in the hardware system was then proposed through the analysis of the variations of the system error caused by the significant error sources when the signal flew through the signal transmission module. In addition, a system parameter, named the signal-to-AC bias ratio (i.e., the ratio between the signal and AC bias, was identified as a direct determinant of the precision of the measured temperature. The temperature error was below 0.1 K when the signal-to-AC bias ratio was higher than 80 dB, and other system errors were not considered. The temperature error was below 0.1 K in the experiments with a commercial magnetic fluid (Sample SOR-10, Ocean Nanotechnology, Springdale, AR, USA when the hardware system of the MNPT was designed with the aforementioned method.

  16. Discontinuous Dynamics of Electric Power System with DC Transmission: A Study on DAE System

    Susuki, Yoshihiko; Hikihara, Takashi; Chiang, Hsiao-Dong

    2008-01-01

    Transient stability of power systems with dc transmission is an important problem for planing and operation of future power networks. A differential-algebraic equation (DAE) system is proposed for transient stability analysis of a practical ac/dc power system which includes one synchronous generator operating onto both ac and dc transmissions. When transient stability analysis is performed using the DAE system, its solutions that represent dynamics of the ac/dc power system become discontinuo...

  17. Discontinuous dynamics of electric power system with dc transmission: A study on DAE system

    Susuki, Yoshihiko; Hikihara, Takashi; Chiang, Hsiao-Dong

    2008-01-01

    Transient stability of power systems with dc transmission is an important problem for planing and operation of future power networks. A differential-algebraic equation (DAE) system is proposed for transient stability analysis of a practical ac/dc power system which includes one synchronous generator operating onto both ac and dc transmissions. When transient stability analysis is performed using the DAE system, its solutions that represent dynamics of the ac/dc power system become discontinuo...

  18. Down hole transmission system

    Hall, David R.; Hall, Jr., H. Tracy

    2007-07-24

    A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. The electrically conducting coil comprises at least two generally fractional loops. In the preferred embodiment, the transmission elements are connected by an electrical conductor. Preferably, the electrical conductor is a coaxial cable. Preferably, the MCEI trough comprises ferrite. In the preferred embodiment, the fractional loops are connected by a connecting cable. In one aspect of the present invention, the connecting cable is a pair of twisted wires. In one embodiment the connecting cable is a shielded pair of twisted wires. In another aspect of the present invention, the connecting cable is a coaxial cable. The connecting cable may be disposed outside of the MCEI circular trough.

  19. 含有柔性输电装置的灵活性输电投资决策模型%Flexibility Investment Decision-Making Model for Transmission Systems With Flexible AC Transmission Equipments

    田廓; 邱柳青; 曾鸣

    2012-01-01

    输电系统投资面临很多潜在的市场风险,这对投资者决策的灵活性提出了较高的要求。考虑输电投资的不确定因素,引入柔性输电装置投资方案,应用最小二乘蒙特卡洛模拟方法建立了投资期权估值模型,在此基础上,建立了优先投资柔性输电装置、优先投资输电线路和同时投资柔性输电装置和输电线路3种方案的期权价值模型,并以社会收益最大化为决策准则,通过Garver一6节点系统及IEEE一24节点系统对方法及模型进行验证。%Transmission network investment is faced with many potential market risks, so it makes higher damnd on the flexibility of investors' decision-making. Considering uncertain factors in the investment for power transmission, a flexible investment project in led in, and by use of least squares Monte Carlo simulation a valuation model for investment options is built. On this basis, three kinds of option value models for investment priority of flexible transmission equipments, investment priority of transmisson lines and simultaneous investment for both flexible transmission equipments and transmisson lines are built, and taking the maximum social benefit as decision rule, the proposed method and models are verified by Garver 6-bus system and 1EEE 24-bus system.

  20. Adapting AC Lines to DC Grids for Large-Scale Renewable Power Transmission

    D. Marene Larruskain

    2014-10-01

    Full Text Available All over the world, governments of different countries are nowadays promoting the use of clean energies in order to achieve sustainable energy systems. In this scenario, since the installed capacity is continuously increasing, renewable sources can play an important role. Notwithstanding that, some important problems may appear when connecting these sources to the grid, being the overload of distribution lines one of the most relevant. In fact, renewable generation is usually connected to the nearest AC grid, although this HV system may not have been designed considering distributed generation. In the particular case of large wind farms, the electrical grid has to transmit all the power generated by wind energy and, as a consequence, the AC system may get overloaded. It is therefore necessary to determine the impact of wind power transmission so that appropriate measures can be taken. Not only are these measures influenced by the amount of power transmitted, but also by the quality of the transmitted power, due to the output voltage fluctuation caused by the highly variable nature of wind. When designing a power grid, although AC systems are usually the most economical solution because of its highly proven technology, HVDC may arise in some cases (e.g. offshore wind farms as an interesting alternative, offering some added values such as lower losses and better controllability. This way, HVDC technology can solve most of the aforementioned problems and has a good potential for future use. Additionally, the fast development of power electronics based on new and powerful semiconductor devices allow the spread of innovative technologies, such as VSC-HVDC, which can be applied to create DC grids. This paper focuses on the main aspects involved in adapting the existing overhead AC lines to DC grids, with the objective of improving the transmission of distributed renewable energy to the centers of consumption.

  1. A novel wireless power and data transmission AC to DC converter for an implantable device.

    Liu, Jhao-Yan; Tang, Kea-Tiong

    2013-01-01

    This article presents a novel AC to DC converter implemented by standard CMOS technology, applied for wireless power transmission. This circuit combines the functions of the rectifier and DC to DC converter, rather than using the rectifier to convert AC to DC and then supplying the required voltage with regulator as in the transitional method. This modification can reduce the power consumption and the area of the circuit. This circuit also transfers the loading condition back to the external circuit by the load shift keying(LSK), determining if the input power is not enough or excessive, which increases the efficiency of the total system. The AC to DC converter is fabricated with the TSMC 90nm CMOS process. The circuit area is 0.071mm(2). The circuit can produce a 1V DC voltage with maximum output current of 10mA from an AC input ranging from 1.5V to 2V, at 1MHz to 10MHz. PMID:24110077

  2. Wireless data signal transmission system

    2014-01-01

    The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver.......The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver....

  3. ECRH transmission system

    The M.I.T. gyrotron group operates a 140 GHz, short pulse (1μs) gyrotron with output power, at present, of up to 175 kW. Output radiation has been obtained in several modes, including TE03 at 140 GHz, TE23 at 137 GHz, TE42 at 128 GHz and TE52 at 145 GHz. Studies have been carried out of the mode purity, both in frequency and in space, of gyrotron output radiation. These studies investigate parasitic mode excitation and mode conversion of gyrotron output power. Far field patterns of gyrotron radiation have been investigated to determine mode symmetry and purity. These results are useful in estimating the efficiency of various transmission systems. Finally, a new approach to quasi-optical transmission lines and mode converters, using axisymmetric optics, is suggested

  4. Characteristics of the magnetic field under hybrid ac/dc high voltage transmission lines

    In recent years, the possibility for ac and dc transmission lines running parallel to each other, sharing the same right-of-way (ROW) or even the same-tower has increased. Design of such hybrid ac/dc networks requires a precise calculation of the magnetic field around and under them. This paper presents quantitative analysis of the magnetic field at 1-m height above ground surface for different hybrid ac/dc transmission lines. Lateral profiles for typical 275, 132 (running in Kuwait), 500, 220 and 132 kV (running in Egypt) ac transmission lines after adding bipolar dc lines are presented. The magnetic vector potential concept, as extended to multi-conductor transmission lines employing the superposition principle is used to model and calculate the RMS values of the magnetic field generated by the hybrid ac/dc lines at any point in the space. The RMS values of the field are determined directly without dividing the ac supply cycle into a sufficient number of subintervals. The presented graphs are useful for setting the maximum allowable ac and dc line current magnitudes, for existing lines, corresponding to a certain safe level of the magnetic field at the edge of right-of-way. (author)

  5. Transient dynamics in electric power system with dc transmission: Fractal growth in stability boundary

    Susuki, Yoshihiko; Hikihara, Takashi

    2005-01-01

    The paper is concerned with transient dynamics and stability of an electric power system with DC transmission. Nowadays, DC transmission systems are widely applied to conventional electric power systems. However, the transient dynamics of AC/DC power systems, affected by the active power that flows into DC transmissions, is not entirely understood. The paper derives a non-symmetrical swing equation system to analyse the transient dynamics of an AC/DC power system. The non-symmetry implies a u...

  6. Security analysis of interconnected AC/DC systems

    Eriksson, Robert

    2015-01-01

    any line or transformer limits. Simulations were performed in a model of the Nordic power system where a dc grid is placed on top. The simulation supports the method as a tool to consider transfer limits in the grid to avoid violate the same and increase the security after a converter outage.......This paper analyses N-1 security in an interconnected ac/dc transmission system using power transfer distribution factors (PTDFs). In the case of a dc converter outage the power needs to be redistributed among the remaining converter to maintain power balance and operation of the dc grid....... The redistribution of power has a sudden effect on the power-flow in the interconnected ac system. This may cause overloading of lines and transformers resulting in disconnection of equipment, and as a consequence cascading failure. The PTDF is used as a method to analyze and avoid violating limits by in the dc...

  7. NEURAL NETWORK BASED OPTIMISATION OF HARMONICS ON AC - DC SIDES OF HVDC TRANSMISSION

    Smriti Tapadar; Tikeshwar Gajpal

    2015-01-01

    This paper investigates possibility of using Neural network for optimisation of AC - DC Harmonics of HVDC Transmission. Dependableness and potency of power transmission has been at the forefront of analysis for a few time and is presently being given essential thought owing to the inflated dependence on current. With the inflated demand for e lectricity, engineers area unit considering completely different strategies of provide arrangement to enhance the ...

  8. AC motor drive system for electric cars

    Morohoshi, Yukinobu; Yoshinori, Naoto; Naito, Hironobu (Fuji Electric Co., Ltd., Tokyo, (Japan))

    1989-08-10

    Various main circuit equipment with large capacity GTO thyristors are outlined for AC and DC electric cars. The configuration of a PWM converter system is presented for the AC main motor drive system of the Shinkansen trains, and its following features are described: the high power factor control capable of keeping a power factor 100% constantly, energy saving by power regenerative braking, the small triple structure with large capacity reverse-conducting GTO thyristors of 4,500V/3,000A, and the reduction of equivalent interfering current and harmonic current by three phase-triple phase difference operation. Furthermore, a control logic equipment with 16 bit MPU and a main transformer are outlined, and the verification test results of the control logic equipment by an analog model simulation and the combinational test results of the commercial equipment are reported. Prototype VVVF inverter system for DC electric cars is also presented. 6 refs., 13 figs., 3 tabs.

  9. Risk Based Assessment of Subsynchronous Resonance in AC/DC Systems

    Adrees, Atia

    2014-01-01

    Risk Based Assessment of Subsynchronous Resonance in compensated AC/DC systemMrs Atia Adrees, The University of Manchester, April 2014This thesis investigates the phenomenon of subsynchronous resonance (SSR) in meshed series compensated AC/DC systems in the presence of operational uncertainties. The main contribution of this research is the novel application of risk assessment methods to SSR studies.In terms of network topology, future electric power transmission networks alongside the curren...

  10. Hybrid-Vehicle Transmission System

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  11. A Simple Load Power Estimator For Quasi-Direct AC-AC Converter System

    Marian GAICEANU; Emil ROSU

    2003-01-01

    In this paper a simple load power estimator for the three-phase quasi-direct acac converter system is reported. Since the ac-ac converter control by means of pulsewidth modulation (PWM) is based on the power balance concept, its load power should be known. Two control boards, based on the dSMC (digital Smart Motion Controller) 30 MIPS 32-bit fixed-point digital signal processor (DSP), were involved in the ac-ac system driving. By using the power balance control, the DC link voltage variation ...

  12. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Fuangpian Phanupong

    2016-01-01

    Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

  13. Beamforming transmission in IEEE 802.11ac under time-varying channels.

    Yu, Heejung; Kim, Taejoon

    2014-01-01

    The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes. PMID:25152927

  14. NEURAL NETWORK BASED OPTIMISATION OF HARMONICS ON AC - DC SIDES OF HVDC TRANSMISSION

    Smriti Tapadar

    2015-06-01

    Full Text Available This paper investigates possibility of using Neural network for optimisation of AC - DC Harmonics of HVDC Transmission. Dependableness and potency of power transmission has been at the forefront of analysis for a few time and is presently being given essential thought owing to the inflated dependence on current. With the inflated demand for e lectricity, engineers area unit considering completely different strategies of provide arrangement to enhance the protection of electricity provide. speedy development within the field of power physical science devices particularly Insulated Gate Bipolar T ransistors (IGBTs has semiconductor diode to the High Voltage electrical energy (HVDC transmission supported Voltage supply Converters (VSCs. This new innovative technology provides substantial technical and economical benefits for direct applications c ompared to standard HVDC transmission. The VSC primarily based HVDC transmission primarily consists of two convertor stations connected by a DC cable. This analysis work presents the performance analysis of VSC based HVDC Transmission . To reinforce the pe rformance of the projected model, the management strategy is ruled by soft computing algorithmic rule i.e. Neural Network. Simulation and results show that the projected model is additional economical with the employment of Neural Network (NN.

  15. Ultrafast Transmission Systems using Coherent Technology

    Ludwig, Reinhold; Richter, Thomas; Palushani, Evarist;

    2011-01-01

    We review recent progress in ultrafast transmission systems. Using coherent detection for simultaneous demultiplexing and demodulation enabled single channel serial 10.2Tb/s transmission over 29km as well as transmission impairment compensation far beyond electronic speed limits.......We review recent progress in ultrafast transmission systems. Using coherent detection for simultaneous demultiplexing and demodulation enabled single channel serial 10.2Tb/s transmission over 29km as well as transmission impairment compensation far beyond electronic speed limits....

  16. Design of 1000-kV AC Single-Circuit Overhead Transmission Line

    Li

    2010-01-01

    The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage. There are no guidelines or standards available for the design of 1 000-kV overhead transmission line in China. Study on key technologies and design schemes shall be carried out to ascertain the technical principles and construction standards for project construction, which are presented in this paper based on the Southeast Shanxi-Nanyang-Jingmen test and demonstration transmission line. A comparison and analysis of technical data and economic indices between UHV line and other lines are also described.

  17. ICT data transmission system based on UDP

    Recently, there are more detectors, longer transmission distance and larger amount of data in ICT transmission system. The traditional data transmission system is difficult to low cost, and at the same time satisfy the long-distance transmission and high-speed transmission. We have designed a kind of data transmission system, in which we used the UDP protocol and implemented in FPGA with verilog programming. Taking into account the low cost and at the same time we have coordinated the contradiction between long-distance and high speed transmission well. (authors)

  18. Transmission system planning in Ontario

    Barrie, D.; Macedo, F.X.; Mcconnach, J.S. [Ontario Hydro, Toronto, ON (Canada)

    1994-12-31

    In recent years, new and modified approaches to planning the large transmission system that serves the province of Ontario, Canada, have been necessary to accommodate the rapidly changing planning environment including slower uncertain growth, ageing of facilities, integration of demand side management and non utility generation options, increased competitiveness, increased financial stresses and affordable constraints. This paper describes some of the new and modified approaches and tools that have been adopted or are being developed by Ontario Hydro to cope with this changing environment. (author) 9 refs., 4 figs.

  19. Nonlinear ac conductivity of interacting 1d electron systems

    Rosenow, Bernd; Nattermann, Thomas

    2004-01-01

    We consider low energy charge transport in one-dimensional (1d) electron systems with short range interactions under the influence of a random potential. Combining RG and instanton methods, we calculate the nonlinear ac conductivity and discuss the crossover between the nonanalytic field dependence of the electric current at zero frequency and the linear ac conductivity at small electric fields and finite frequency.

  20. Theory of ac loss in power transmission cables with second generation high temperature superconductor wires

    While a considerable amount of work has been done in an effort to understand ac losses in power transmission cables made of first generation high temperature superconductor (HTS) wires, use of second generation (2G) HTS wires brings in some new considerations. The high critical current density of the HTS layer in 2G wires reduces the surface superconductor hysteretic losses, for which a new formula is derived. Instead, gap and polygonal losses, flux transfer losses in imbalanced two-layer cables and ferromagnetic losses for wires with NiW substrates constitute the principal contributions. A formula for the flux transfer losses is also derived with a paramagnetic approximation for the substrate. Current imbalance and losses associated with the magnetic substrate can be minimized by orienting the substrates of the inner winding inward and the outer winding outward.

  1. Design studies for the Mead-Phoenix 500 kV AC transmission project

    Thallam, R.S.; Lundquist, T.G.; Gerlach, D.W. [Salt River Project, Phoenix, AZ (United States); Atmuri, S.R. [Teshmont Consultants Inc., Winnipeg, Manitoba (Canada); Selin, D.A. [Arizona Public Service Co., Phoenix, AZ (United States)

    1995-10-01

    The Mead-Phoenix 500 kV ac line is 243 miles long and runs parallel to the existing Mead-Liberty 345 kV line. This line is planned for 70% series and 70% shunt compensation; it also incorporates the first application of a 50 kV phase shifting transformer that enables a 1,300 MW transmission capacity. This paper presents the design studies that were undertaken in arriving at the equipment ratings and insulation levels that lead to the equipment specifications. The shunt reactor switching requirements utilizing MOV across the breaker, line switching with line connected arresters and the breaker transient recovery voltage are also dealt with in the paper.

  2. Measurements of light transmission in deep sea with the AC9 trasmissometer

    The NEMO Collaboration aims to construct an underwater Cherenkov detector in the Mediterranean Sea, able to act as a neutrino telescope. One of the main tasks of this project, which implies difficult technological challenges, is the selection of an adequate marine site. In this framework the knowledge of light transmission properties in deep seawater is extremely important. The collaboration has measured optical properties in several marine sites near the Italian coasts, at depths >3000 m, using a setup based on a AC9, a commercial trasmissometer, manufactured by WETLabs. The results obtained for the two sites reported in this paper (Alicudi and Ustica), show that deep seawater optical properties are comparable to those of the clearest waters

  3. Measurements of light transmission in deep sea with the AC9 trasmissometer

    Capone, A; Grimaldi, A; Habel, R; Presti, D L; Migneco, E; Masullo, R; Moro, F; Petruccetti, M; Petta, C; Piattelli, P; Randazzo, N; Riccobene, G; Salusti, E; Sapienza, P; Sedita, M; Trasatti, L; Ursella, L; Capone, Antonio; Digaetano, Tullio; Grimaldi, Antonio; Habel, Roberto; Presti, Domenico Lo; Migneco, Emilio; Masullo, Rocco; Moro, Fulvio; Petruccetti, Marco; Petta, Catia; Piattelli, Paolo; Randazzo, Nunzio; Riccobene, Giorgio; Salusti, Ettore; Sapienza, Piera; Sedita, Mario; Trasatti, Luciano; Ursella, Laura

    2002-01-01

    The NEMO Collaboration aims to construct an underwater Cerenkov detector in the Mediterranean Sea, able to act as a neutrino telescope. One of the main tasks of this project, which implies difficult technological challenges, is the selection of an adequate marine site. In this framework the knowledge of light transmission properties in deep seawater is extremely important. The collaboration has measured optical properties in several marine sites near the Italian coasts, at depths >3000 m, using a set-up based on a AC9, a commercial trasmissometer, manufactured by WETLabs. The results obtained for the two sites reported in this paper Alicudi and Ustica, show that deep seawater optical properties are comparable to those of the clearest waters.

  4. Harmonics in transmission power systems

    Wiechowski, Wojciech Tomasz

    , provided that background harmonic distortion, and the network configuration, are not changing during the measurement. It is shown that switching of a shunt linear power system component can result in variation of the harmonic levels that can be measured and used to verify the harmonic model of the network......, in order to determine which power system component, when switched, results in the largest change in harmonic levels, some initial harmonic simulations, using the created harmonic model of Energinet.dk transmission network, are performed. The criterion is that the measuring equipment shall not be installed...... of the measurements. The conclusion is that a key requirement of this technique is a good synchronization of the measurements. Capacitive voltage transformers installed at the 400 kV substations are not suited to measure higher frequencies and the capacitive taps of the 400 kV/150 kV autotransformer bushings are used...

  5. AC Versus DC Link Comparison Based on Power Flow Analysis of a Multimachine Power System

    Mohammed Abdeljalil DJEHAF

    2014-02-01

    Full Text Available Deregulation and privatization is posing new challenges on high voltage transmission and on distributions systems as well. An increasingly liberalized market will encourage trading opportunities to be identified and developed. High voltage power electronics, such as HVDC (High Voltage Direct Current and FACTS (Flexible AC Transmission Systems provide the necessary features to avoid technical problems in heavily loaded power systems; HVDC offers most advantages: it can be used for system interconnection and for control of power flow as well. The major benefit of HVDC is its incorporated ability for fault-current blocking, which is not possible with synchronous AC links. In addition, HVDC can effectively support the surrounding AC systems in case of transient fault conditions and it serves as firewall against cascading disturbances. This paper presents a comparison between HVDC link and an HVAC link in a 29 Bus multimachine system, based on load flow analysis using Newton-Raphson method for the AC link case, and sequential method for the HVDC link case.

  6. Power Electronics for Mitigation of Voltage Sags and Improved Control of AC Power Systems

    Magalhães de Oliveira, Marcio

    2000-01-01

    The thesis deals with the application of compensators andswitches based on power electronics in AC transmission anddistribution systems. The objective of the studieddevices/equipment is the power flow and voltage control intransmission systems and the mitigation of voltage sags andmomentary interruptions to critical loads in distributionsystems. For validating the power electronics based devices/equipmentdescribed in the thesis, scaled models at a real-time simulatorhave been built. Simulatio...

  7. Electromagnetic Transient Analysis on Xinjiang 750 kV AC Transmission System%新疆750kV交流输电系统电磁暂态分析

    刘青

    2011-01-01

    结合新疆地区乌北-吐鲁番-哈密750 kV输变电工程,研究了线路各种运行情况下的潜供电流、恢复电压,验证了高抗中性点小电抗取值的合理性.对于同杆架设双回路段,计算了正常运行线路对另一回检修线路的感应电压和感应电流.研究了各种运行方式下的工频过电压以及合闸操作过电压,同时分析了合闸空载变压器的过电压和励磁涌流.最后计算了光纤复合架空地线(optical power ground wire,OPGW)采用分段绝缘单点接地方式时的感应电压.电磁暂态程序(EMTP)的仿真计算表明,潜供电流、恢复电压数值不大,高抗中性点小电抗取值合适.同杆双回路接地刀闸电气参数符合要求.线路两端装设高抗后,工频过电压符合我国关于超高压线路工频过电压的要求.线路三相合闸、单相重合闸操作过电压不高,而且对金属氧化物避雷器(MOA)热容量要求不高.合闸空载变压器过电压和励磁涌流较小.OPGW感应电压不大,数值和分段长度基本成正比,采用分段绝缘单点接地方式利于减小线路电能损耗.%It is necessary to study the electromagnetic transients of 7 50 kV transmission line so as to provide reasonable reference for Insulation Coordination. Combined with Xinjiang 750 kV transmission system, the secondary arc current and the recovery voltage were studied. For the double circuit transmission line, the induction voltage and current were calculated. Moreover, the power frequency over-voltage and switching over-voltage, as well as the inrush currents and the over-voltages of closing no-load transformer, were studied. The induction voltage of optical fiber composite overhead ground wire (OPGW) was calculated, which was sectionally insulated and unilaterally grounded. The theoretical analysis and simulated results of Electro Magnetic Transient Program ( EMTP) show that the value of neutral reactance is selected suitably. The earth switch

  8. Beta attenuation transmission system (BATS)

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm2, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A 90Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (μP) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined

  9. Beta attenuation transmission system (BATS)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  10. HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

    Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

    1982-09-01

    Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

  11. RESEARCH OF DYNAMIC CHARACTERIATIC FOR TRANSMISSION SYSTEM

    2001-01-01

    The kinetic precision of transmission chain is a key problem in the research of gear cutting machine transmission system.The traditional point of view is to consider the transmission chain as a geometrical meshing system,thus it is deemed that the kinetic precision of the transmission chain only depends on the manufacturing and assembly errors of its transmission parts.But further research reveals that the kinetic precision of transmission system is closely related with the system dynamic effects.Therefore,from the dynamic point of view,it is discerned that not only deems the transmission chain as a geometrical meshing system but also considers it as a dynamic system performing with torsional vibration.On the basis of analyses and processes of measuring data of samples from tests of cutting machine's kinetic precision of transmission chain,the results represent that the influences of dynamic characteristics of the transmission system on its kinetic precision is non-negligible.Experimental methods for discerning the transfer function of torsional vibration of gear transmission system and experimental results have been given.

  12. Behaviour analysis of AC-600 passive safety systems

    Southwest Center of Reactor Engineering Research and Design has finished the first step conceptual design of 600 mwe advanced PWR (AC-600). The main research emphases of AC-600 conceptual design include the advanced reactor core, the passive safety systems and the simplification. The passive safety systems of AC-600 consist of two reactor make up water tanks, two accumulators, two emergency feedwater tanks, two emergency natural draft air condensers, a containment water jacket and an enhanced primary cycle natural circulation flow system. 25% of the rated reactor power can be removed by the natural circulation cooling. The full pressure reactor make up water tanks are able to provide enough borated water which would be injected into the reactor coolant system during small LOCA. The coolant natural circulations can be established in the primary system and the passive secondary emergency feedwater system, removing residual heat from the reactor core to the atmosphere when station blackout occurs. It is indicated from analysis that the containment diameter of AC-600 is about 35 m. The large tanks and the large vertical distances between the tanks and reactor core are the main reason of using the big containment. It is also indicated from analysis that the low head safety injection pumps are required in AC-600 design to assure the recirculation system operation when large LOCA occurs. The reliability of AC-600 engineered safety systems is increased because the function of the passive safety systems is conducted through the immutable natural laws. The paper discusses the natural circulation ability and safety behavior of the passive safety systems during LOCA or station blackout for AC-600. The passive limits to excess reactivity and thermal hydraulic transients are also preliminarily discussed. Figs and tabs

  13. To the problem of topological optimization of data processing and transmission networks in development of the automatic control system ''Atom''

    Some optimization problems occurring in developing the automatic control system (ASC) of a commercial amalgamation (ACS-ATOM), assessments of economically optimal structure of location of computation centres and means of data transmission in particular are considered

  14. Study of Power Flow Algorithm of AC/DC Distribution System including VSC-MTDC

    Haifeng Liang

    2015-08-01

    Full Text Available In recent years, distributed generation and a large number of sensitive AC and DC loads have been connected to distribution networks, which introduce a series of challenges to distribution network operators (DNOs. In addition, the advantages of DC distribution networks, such as the energy conservation and emission reduction, mean that the voltage source converter based multi-terminal direct current (VSC-MTDC for AC/DC distribution systems demonstrates a great potential, hence drawing growing research interest. In this paper, considering losses of the reactor, the filter and the converter, a mathematical model of VSC-HVDC for the load flow analysis is derived. An AC/DC distribution network architecture has been built, based on which the differences in modified equations of the VSC-MTDC-based network under different control modes are analyzed. In addition, corresponding interface functions under five control modes are provided, and a back/forward iterative algorithm which is applied to power flow calculation of the AC/DC distribution system including VSC-MTDC is proposed. Finally, by calculating the power flow of the modified IEEE14 AC/DC distribution network, the efficiency and validity of the model and algorithm are evaluated. With various distributed generations connected to the network at appropriate locations, power flow results show that network losses and utilization of transmission networks are effectively reduced.

  15. Control Structures for VSC-based FACTS Devices under Normal and Faulted AC-systems

    Babaei, Saman

    This thesis is concerned with improving the Flexible AC Transmission Systems (FACTS) devices performance under the normal and fault AC-system conditions by proposing new control structures and also converter topologies. The combination of the increasing electricity demand and restrictions in expanding the power system infrastructures has urged the utility owners to deploy the utility-scaled power electronics in the power system. Basically, FACTS is referred to the application of the power electronics in the power systems. Voltage Source Converter (VSC) is the preferred building block of the FACTS devices and many other utility-scale power electronics applications. Despite of advances in the semiconductor technology and ultra-fast microprocessor based controllers, there are still many issues to address and room to improve[25]. An attempt is made in this thesis to address these important issues of the VSC-based FACTS devices and provide solutions to improve them.

  16. Reliability of emergency ac power systems at nuclear power plants

    Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project

  17. A Simple Load Power Estimator For Quasi-Direct AC-AC Converter System

    Marian GAICEANU

    2003-12-01

    Full Text Available In this paper a simple load power estimator for the three-phase quasi-direct acac converter system is reported. Since the ac-ac converter control by means of pulsewidth modulation (PWM is based on the power balance concept, its load power should be known. Two control boards, based on the dSMC (digital Smart Motion Controller 30 MIPS 32-bit fixed-point digital signal processor (DSP, were involved in the ac-ac system driving. By using the power balance control, the DC link voltage variation at the load changes can be reduced. In this way a small DC link capacitor is required to handle the dc voltage error control. The feed-forward (Sul and Lipo, 1990 current component provides fast correction of the reference control to load power variation. In order to obtain the feed-forward current component, the load power must to be known. In this paper the load power is estimated from the dc link, indirectly, through a dc load current estimator. In this way the author overcomes the use of the serial communication between control boards (Gaiceanu, 2004 in order to deliver the load power information from the inverter side. The load current estimator is based on the DC link voltage and on the load current of the supply converter. This method presents certain advantages instead of using measured method, which requires a low pass filter: no time delay, the feed-forward current component has no ripple, no additional hardware, and more fast control response. Through simulation and experimental results the performances of the proposed load current estimator scheme are demonstrated.

  18. Research on AC Variable Frequency Speed Regulation System

    Ou Bing-Xian; Li Qing-Zhong; Yan Jun-Xia

    2013-01-01

    In view of shortcomings existing in shear speed control system, shearer AC speed regulating system is designed and studied. The mathematical model of three-phase asynchronous motor in rotating coordinate system is established, and PWM technology of space vector is discussed. Software and hardware of the asynchronous motor vector control variable frequency speed regulating system are designed. The simulation of system based on Matlab is made and the correctness and feasibility of the sys...

  19. Coordinated Stability Control of Wind-Thermal Hybrid AC/DC Power System

    Zhiqing Yao

    2015-01-01

    Full Text Available The wind-thermal hybrid power transmission will someday be the main form of transmitting wind power in China but such transmission mode is poor in system stability. In this paper, a coordinated stability control strategy is proposed to improve the system stability. Firstly, the mathematical model of doubly fed wind farms and DC power transmission system is established. The rapid power controllability of large-scale wind farms is discussed based on DFIG model and wide-field optical fiber delay feature. Secondly, low frequency oscillation and power-angle stability are analyzed and discussed under the hybrid transmission mode of a conventional power plant with wind farms. A coordinated control strategy for the wind-thermal hybrid AC/DC power system is proposed and an experimental prototype is made. Finally, real time simulation modeling is set up through Real Time Digital Simulator (RTDS, including wind power system and synchronous generator system and DC power transmission system. The experimental prototype is connected with RTDS for joint debugging. Joint debugging result shows that, under the coordinated control strategy, the experimental prototype is conductive to enhance the grid damping and effectively prevents the grid from occurring low frequency oscillation. It can also increase the transient power-angle stability of a power system.

  20. Development of an AC Module System: Final Technical Report

    Suparna Kadam; Miles Russell

    2012-06-15

    The GreenRay Inc. program focused on simplifying solar electricity and making it affordable and accessible to the mainstream population. This was accomplished by integrating a solar module, micro-inverter, mounting and monitoring into a reliable, 'plug and play' AC system for residential rooftops, offering the following advantages: (1) Reduced Cost: Reduction in installation labor with fewer components, faster mounting, faster wiring. (2) Maximized Energy Production: Each AC Module operates at its maximum, reducing overall losses from shading, mismatch, or module downtime. (3) Increased Safety. Electrical and fire safety experts agree that AC Modules have significant benefits, with no energized wiring or live connections during installation, maintenance or emergency conditions. (4) Simplified PV for a Broader Group of Installers. Dramatic simplification of design and installation of a solar power system, enabling faster and more efficient delivery of the product into the market through well-established, mainstream channels. This makes solar more accessible to the public. (5) Broadened the Rooftop Market: AC Modules enable solar for many homes that have shading, split roofs, or obstructions. In addition, due to the smaller building block size of 200W vs. 1000W, homeowners with budget limitations can start small and add to their systems over time. Through this DOE program GreenRay developed the all-in-one AC Module system with an integrated PV Module and microinverter, custom residential mounting and performance monitoring. Development efforts took the product from its initial concept, through prototypes, to a commercial product sold and deployed in the residential market. This pilot deployment has demonstrated the technical effectiveness of the AC Module system in meeting the needs and solving the problems of the residential market. While more expensive than the traditional central inverter systems at the pilot scale, the economics of AC Modules become

  1. Sustainable AC/AC hybrid electrochemical capacitors in aqueous electrolyte approaching the performance of organic systems

    Abbas, Qamar; Babuchowska, Paulina; Frąckowiak, Elżbieta; Béguin, François

    2016-09-01

    A high energy hybrid AC/AC electrochemical capacitor has been realized in aqueous Li2SO4+KI electrolyte mixture. Owing to the redox processes associated with the 2I-/I2 system, the positive electrode operates in narrow potential range and displays high capacity. During prolonged potentiostatic floating at 1.6 V, the hybrid cell demonstrates remarkably stable capacitance and resistance. Analyses by temperature programmed desorption after floating at 1.6 V proved that oxidation of the positive AC electrode is prevented by the use of Li2SO4+KI, which enables the maximum potential of this electrode to be shifted below the water oxidation potential. When charged at 0.2 A g-1 up to U = 1.6 V, the hybrid cell displays a high capacitance of 75 F g-1 (300 F g-1 per mass of one electrode) compared to 47 F g-1 (188 F g-1 per mass of one electrode) for a symmetric cell in Li2SO4. At 0.2 A g-1 up to 1.6 V, the hybrid capacitor in Li2SO4+KI displays an energy density of 26 Wh kg-1 which approaches the energy density of 30.9 Wh kg-1 measured when the same carbon is implemented in a capacitor using TEABF4/ACN electrolyte and charged up to 2.5 V.

  2. Power Improvement of Transmission Line Using High Voltage Direct Current (Hvdc Transmission System

    Lasisi, H

    2016-08-01

    Full Text Available The use of long EHV (Extremely High Voltage ac lines for the transmission of electrical energy increases the line reactance and susceptance which limits the thermal loadings on the line in order to keep sufficient margin against transient instability. With the scheme proposed in this paper, it is possible to load the lines very close to their limit with zero reactance and susceptance. The conductors are allowed to carry usual ac along with dc superimposed on it. The added dc power flow does not cause any transient instability. The scheme comprises a twelve-pulse bridge rectifier, dc-links, pulse width modulated (PSW-voltage sourced inverter (VSI and converter transformers. The master current controller is used to implement the scheme which senses ac current and regulates the dc current orders for converters online such that conductor current never exceeds its thermal limit. This paper gives the feasibility of converting a double circuit ac line into composite ac–dc power transmission line given the advantage of stability improvement, damping oscillations, voltage stabilization and reactive power compensation for ac weak buses. Simulation and experimental studies using MATLAB (Matrix Laboratory are carried out for the coordinated control as well as independent control of ac and dc power transmissions.

  3. Feasibility study of wireless power transmission systems

    Robinson, W. J., Jr.

    1968-01-01

    Wireless microwave or laser energy transfers power from a manned earth-orbiting central station to unmanned astronomical substations. More efficient systems are required for the microwave power transmission.

  4. Transmission Expansion Planning in Deregulated Power Systems

    Oloomi Buygi, Majid

    2004-01-01

    The main goal of this thesis is to present a centralized static approach for transmission expansion planning in deregulated power systems. Restructuring and deregulation have unbundled the roles of network stakeholders. They exposed transmission planner to the new objectives and uncertainties. Unbundling the roles has brought new challenges for stakeholders. In these environments, stakeholders have different desires and expectations from the performance and expansion of the system. Therefore,...

  5. AC system stabilization via phase shift transformer with thyristor commutation

    Oliveira, Jose Carlos de; Guimaraes, Geraldo Caixeta; Moraes, Adelio Jose [Uberlandia Univ., MG (Brazil); Abreu, Jose Policarpo G. de [Escola Federal de Engenharia de Itajuba, MG (Brazil); Oliveira, Edimar Jose de [Juiz de Fora Univ., MG (Brazil)

    1994-12-31

    This article aims to present initially the constructive and operative forms of a phase-shift autotransformer which provides both magnitude and phase angle change through thyristor commutation, including a technic to reduce the number of thyristors. Following, it is proposed a control system to make such equipment an efficient AC system stabilizing tool. It is presented some simulation results to show the operation of this transformer in an electrical system. (author) 3 refs., 11 figs., 3 tabs.

  6. Methods, apparatus, and systems for monitoring transmission systems

    Polk, Robert E; Svoboda, John M.; West, Phillip B.; Heath, Gail L.; Scott, Clark L.

    2016-07-19

    A sensing platform for monitoring a transmission system, and method therefor, may include a sensor that senses one or more conditions relating to a condition of the transmission system and/or the condition of an environment around the transmission system. A control system operatively associated with the sensor produces output data based on an output signal produced by the sensor. A transmitter operatively associated with the control system transmits the output data from the control system.

  7. Integral equations method and the transmission problem for the Stokes system

    Medková, Dagmar

    2015-01-01

    Roč. 39, č. 1 (2015), s. 53-71. ISSN 1450-9628 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : transmission problem * Stokes system * integral equation method Subject RIV: BA - General Mathematics https ://imi.pmf.kg.ac.rs/kjm/pub/kjom391/kjom391-6.pdf

  8. APEnet+ 34 Gbps data transmission system and custom transmission logic

    APEnet+ is a point-to-point, low-latency, 3D-torus network controller integrated in a PCIe Gen2 board based on the Altera Stratix IV FPGA. We characterize the transmission system (embedded transceivers driving external QSFP+ modules) analyzing signal integrity, throughput, latency, BER and jitter at different data rates up to 34 Gbps. We estimate the efficiency of a custom logic able to sustain 2.6 GB/s per link with an FPGA on-chip memory footprint of 40 KB, providing deadlock-free routing and systemic awareness of faults. Finally, we show the preliminary results obtained with the embedded transceivers of a next-generation FPGA and outline some ideas to increase the performance with the same FPGA memory footprint

  9. Control of DC voltage in Multi-Terminal HVDC Transmission (MTDC) Systems

    Nazari, Mohammad

    2014-01-01

    With recent advances in power electronic technology, High-Voltage Direct Current (HVDC) transmission system has become an alternative for transmitting power especially over long distances. Multi-Terminal HVDC (MTDC) systems are proposed as HVDC systems with more than two terminals. These systems can be geographically wide. While in AC grids, frequency is a global variable, in MTDC systems, DC voltage can be considered as its dual. However, unlike frequency, DC voltage can not be equal across ...

  10. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Fuangpian Phanupong; Zafar Taimoor; Ruankorn Sayan; Suwanasri Thanapong

    2016-01-01

    Nowadays, using of High Voltage Direct Current (HVDC) transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC) line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage s...

  11. Overview of remote data transmission systems

    Paulson, Richard W.

    Remote data transmission systems for monitoring the environment are reviewed, including the Argos system, geostationary meteorological satellite systems, and the meteorburst technique which relies on micrometeor trails in the atmosphere to reflect radio messages between a hydrologic station and an interrogation site. The snow telemetry hydrologic data collection system, Landsat series of satellites, synchronous meteorological and geostationary operational environmental satellites are discussed. Specific elements of these systems are examined and major operators and users of the systems are identified.

  12. Active Harmonics Filtering of Distributed AC System

    Shahbaz, Muhammad

    2012-01-01

    The tendency of connecting the Power Electronic loads and distributed power plants through Power Electronic converters is increasing day by day. These Power Electronic converters and loads are the sources of harmonics and reactive power which greatly affect the performance of the power system network. In a weak power grid, the voltage unbalance and non-sinusoidal regimes are very common. Under such circumstances not only the controllability of the power grid itself but also the controllabilit...

  13. System and method for determining stator winding resistance in an AC motor using motor drives

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  14. The minimization of ac phase noise in interferometric systems

    Filinski, Ignacy; Gordon, R A

    1994-01-01

    A simple step-by-step procedure, including several novel techniques discussed in the Appendices, is given for minimizing ac phase noise in typical interferometric systems such as two-beam interferometers, holographic setups, four-wave mixers, etc. Special attention is given to index of refraction...... fluctuations, direct mechanical coupling, and acoustic coupling, whose importance in determining ac phase noise in interferometric systems has not been adequately treated. The minimization procedure must be carried out while continuously monitoring the phase noise which can be done very simply by using a...... in optics. Thus, the necessity of eliminating the effects of index of refraction fluctuations which degrade the performance of all interferometers is pointed out as the first priority. A substantial decrease of the effects of all vibrating, rotating, or flowing masses (e.g., cooling lines) in direct...

  15. Eco-design of power transmissions systems

    The demand to preserve the environment and form a sustainable development is greatly increasing in the recent decades all over the world, and this environmental concern is also merged in electrical power industry, resulting in many eco-design approaches in Transmission and Distribution (T and D) industries. As a method of eco-design, Life Cycle Assessment (LCA) is a systematic tool that enables the assessment of the environmental impacts of a product or service throughout its entire life cycle, i.e. raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence. In T and D industries, LCA has been done for a lot of products individually, in order to see one product's environmental impacts and to seek for ways of improving its environmental performance. This eco-design for product approach is a rather well-developed trend, however, as only a single electrical product cannot provide the electrical power to users, electrical system consists of a huge number of components, in order to investigate system's environmental profile, the entire environmental profiles of different composing products has to be integrated systematically, that is to say, a system approach is needed. Under this philosophy, the study 'Eco-design of Power Transmission Systems' is conducted in this thesis, with the purpose of analysing the transmission systems' environmental impacts, locating the major environmental burden sources of transmission systems, selecting and/or developing methodologies of reducing its environmental impacts. (author)

  16. Global dynamic modeling of a transmission system

    Choy, F. K.; Qian, W.

    1993-01-01

    The work performed on global dynamic simulation and noise correlation of gear transmission systems at the University of Akron is outlined. The objective is to develop a comprehensive procedure to simulate the dynamics of the gear transmission system coupled with the effects of gear box vibrations. The developed numerical model is benchmarked with results from experimental tests at NASA Lewis Research Center. The modal synthesis approach is used to develop the global transient vibration analysis procedure used in the model. Modal dynamic characteristics of the rotor-gear-bearing system are calculated by the matrix transfer method while those of the gear box are evaluated by the finite element method (NASTRAN). A three-dimensional, axial-lateral coupled bearing model is used to couple the rotor vibrations with the gear box motion. The vibrations between the individual rotor systems are coupled through the nonlinear gear mesh interactions. The global equations of motion are solved in modal coordinates and the transient vibration of the system is evaluated by a variable time-stepping integration scheme. The relationship between housing vibration and resulting noise of the gear transmission system is generated by linear transfer functions using experimental data. A nonlinear relationship of the noise components to the fundamental mesh frequency is developed using the hypercoherence function. The numerically simulated vibrations and predicted noise of the gear transmission system are compared with the experimental results from the gear noise test rig at NASA Lewis Research Center. Results of the comparison indicate that the global dynamic model developed can accurately simulate the dynamics of a gear transmission system.

  17. Global dynamic modeling of a transmission system

    Choy, F. K.; Qian, W.

    1993-04-01

    The work performed on global dynamic simulation and noise correlation of gear transmission systems at the University of Akron is outlined. The objective is to develop a comprehensive procedure to simulate the dynamics of the gear transmission system coupled with the effects of gear box vibrations. The developed numerical model is benchmarked with results from experimental tests at NASA Lewis Research Center. The modal synthesis approach is used to develop the global transient vibration analysis procedure used in the model. Modal dynamic characteristics of the rotor-gear-bearing system are calculated by the matrix transfer method while those of the gear box are evaluated by the finite element method (NASTRAN). A three-dimensional, axial-lateral coupled bearing model is used to couple the rotor vibrations with the gear box motion. The vibrations between the individual rotor systems are coupled through the nonlinear gear mesh interactions. The global equations of motion are solved in modal coordinates and the transient vibration of the system is evaluated by a variable time-stepping integration scheme. The relationship between housing vibration and resulting noise of the gear transmission system is generated by linear transfer functions using experimental data. A nonlinear relationship of the noise components to the fundamental mesh frequency is developed using the hypercoherence function. The numerically simulated vibrations and predicted noise of the gear transmission system are compared with the experimental results from the gear noise test rig at NASA Lewis Research Center. Results of the comparison indicate that the global dynamic model developed can accurately simulate the dynamics of a gear transmission system.

  18. International Benchmarking of Electricity Transmission System Operators

    Agrell, Per J.; Bogetoft, Peter

    2014-01-01

    Electricity transmission system operators (TSO) in Europe are increasing subject to high-powered performance-based regulation, such as revenue-cap regimes. The determination of the parameters in such regimes is challenging for national regulatory authorities (NRA), since there is normally a single...

  19. Wireless Transmission System for Vehicle Inspection Data

    LIU Yuan; MIAO Chang-yun

    2008-01-01

    Based on general packet radio service(GPRS) and TCP/IP protocol, a wireless transmission system of vehicle inspection data is designed. Basic structure and work theory are expounded. SIM300 designed by SIMCOM is used for client GPRS communication module. Using Winsock control of visual basic(VB), the client and server communication has been accomplished. By means of a client and server communications software, the remote wireless transmission of vehicle inspection data has been accomplished also. The server management software has been developed by using Microsoft SQL Server 2000 and VB6.0. Functions of software include import, inquiry, export and maintenance of test data.

  20. Radiation transmission pipe thickness measurement system

    Fuji Electric Systems can be measured from the outer insulation of the transmission Characteristics and radiation detection equipment had been developed that can measure pipe wall thinning in plant and running, the recruitment of another three-beam calculation method by pipe thickness measurement system was developed to measure the thickness of the pipe side. This equipment has been possible to measure the thickness of the circumferential profile of the pipe attachment by adopting automatic rotation. (author)

  1. Power delivery in multiterminal VSC-HVDC transmission system for offshore wind power applications

    Silva, Rodrigo da; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    This paper deals with one of the challenges in the field of offshore wind power systems: power transmission among the wind farms and the land when there is more than one AC grid to be considered. This case is known in the literature as multiterminal connection. The proposed studies are going to present three strategies in order to connect one offshore wind farm and two AC grids with different power ratings. The first strategy shows the easier case when one onshore station defines the power tr...

  2. System and Battery Charge Control for PV-Powered AC Lighting Systems

    Kern, G.

    1999-04-01

    This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

  3. Radio transmission system for industrial area

    The paper deals with a data transmission system operating in a large, noisy industrial area. The radio transmission system permits data and commands communication between the local units of collecting data and a central monitoring and/or command station ( dispatch). The communication support are radio waves in the range 450 MHz. The transducers are of transmitter type, with 4-20 mA output signal, providing information about environmental and/or work parameters. Data are primarily acquisitioned in a data logger with microcontroller, then transmitted via a FSK radio modem and a radio station to the dispatch. Data logger can also be connected in a network. The dispatch personal computer receives and processes data and transmits commands. The system functioning is supervised by a communication software in MCS - 51 assembler and an application software in Visual C++. (author)

  4. Application of AC servo motor on the in-core neutron flux instrumentation system

    The application of ac servo motor in the In-Core Neutron Flux Instrumentation System is described. The hardware component of ac servo motor control system is different from the dc motor control system. The effect of two control system on the instrumentation system is compared. The ac servo motor control system can improve the accuracy of the motion control, optimize the speed control and increase the reliability. (authors)

  5. Transmission techniques for 4G systems

    Da Silva, Mario Marques

    2012-01-01

    Fourth Generation (4G) wireless communication systems support current and emergent multimedia services such as mobile TV, social networks and gaming, high-definition TV, video teleconferencing, and messaging services. These systems feature the All-over-IP concept and boast improved quality of service. Several important R&D activities are currently under way in the field of wireless communications for 4G systems, but the coverage is widespread in the literature. Transmission Techniques for 4G Systems presents a compilation of the latest developments in the field of wireless communications for 4

  6. Nonlinear control of voltage source converters in AC-DC power system.

    Dash, P K; Nayak, N

    2014-07-01

    This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations. PMID:24906895

  7. A transgenic system for generation of transposon Ac/Ds-induced chromosome rearrangements in rice

    Yu, Chuanhe; Han, FangPu; Zhang, Jianbo; Birchler, James; Peterson, Thomas

    2012-01-01

    The maize Activator (Ac)/Dissociation (Ds) transposable element system has been used in a variety of plants for insertional mutagenesis. Ac/Ds elements can also generate genome rearrangements via alternative transposition reactions which involve the termini of closely linked transposons. Here, we introduced a transgene containing reverse-oriented Ac/Ds termini together with an Ac transposase gene into rice (Oryza sativa ssp. japonica cv. Nipponbare). Among the transgenic progeny, we identifie...

  8. Analysis of Interline Power Flow Controller (IPFC Location in Power Transmission Systems

    Amir Kahyaei

    2011-07-01

    Full Text Available The Interline Power Flow Controller (IPFC is one of the latest generation Flexible AC Transmission Systems (FACTS controller used to control power flows of multiple transmission lines. The aim of this paper is investigation of the effect of location of IPFC on profile of voltage and real and reactive power flow in transmission lines in power system. This model is incorporated in Newton- Raphson (NR power flow algorithm to study the power flow control in transmission lines in which IPFC is placed. A program in MATLAB/SIMULINK has been written in order to extend conventional NR algorithm based on this model. Numerical results are carried out on a standard power system. The results without and with IPFC for various locations are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model.

  9. Optimizing DC Voltage Droop Settings for AC/DC System Interactions

    Eriksson, Robert; Beerten, Jef; Ghandari, Mehrdad; Belmans, Ronnie

    2014-01-01

    In this paper, a methodology is presented to optimize the dc voltage droop settings in a multiterminal voltage-source converter high-voltage direct-current system with respect to the ac system stability. Implementing dc voltage droop control enables having multiple converters assisting the system in case of a converter outage. However, the abrupt power setpoint changes create additional stress in the ac system, especially when multiple converters are connected to the same interconnected ac sy...

  10. Switching in electrical transmission and distribution systems

    Smeets, René; Kapetanovic, Mirsad; Peelo, David F; Janssen, Anton

    2014-01-01

    Switching in Electrical Transmission and Distribution Systems presents the issues and technological solutions associated with switching in power systems, from medium to ultra-high voltage. The book systematically discusses the electrical aspects of switching, details the way load and fault currents are interrupted, the impact of fault currents, and compares switching equipment in particular circuit-breakers. The authors also explain all examples of practical switching phenomena by examining real measurements from switching tests. Other highlights include: up to date commentary on new develo

  11. Using SMES as a multi-purpose interface in power generation, transmission and distribution systems

    Tam, Kwa-Sur; Zhang, X.; Yarali, A.

    The objectives are to introduce the concept of the multiterminal superconductive magnetic energy storage (MSMES) scheme and to show that new SMES applications and more SMES benefits to electric power systems can be realized by using MSMES. The authors show a schematic diagram of the conventional SMES system. The SMES magnet is charged and discharged through one dc/ac converter terminal and the SMES unit is connected as a shunt device to the ac power system. The authors show a schematic diagram of a three-terminal SMES system which is used to explain the principle of operation of a MSMES system. Potential applications of MSMES systems in power generation, transmission, and distribution systems are discussed.

  12. GRID-CONNECTECD DOUBLE-STAGE AC-AC POWER CONVERTER FOR CSP RENEWABLE ENERGY SYSTEMS

    Sorrentino, Vincenzo

    2015-01-01

    In the last years the renewable energy sources have known a state of their advanced diffusion considering their advantages compared to the traditional energy sources like fossil fuels. For this reason the combined heat and power (CHP) plant fueled by renewable sources are widely used. The purpose of this Ph.D. thesis is the design of a new Grid-connected Double-Stage AC-DC/DC-AC Power Converter (DSACPC) for a Concentrating Solar plant for Combined generation of Heat and Power (CS-CHP), th...

  13. Research on closed-loop simulation system for digital AC servo system

    HAO ShuangHui; ZHENG WeiFeng; HAO MingHui; MA RuQi; LI Hong

    2009-01-01

    An intelligent and efficient closed-loop simulation system without any hardware is proposed for AC servo system. According to the characteristics of AC servo system and its control processor, the code executing platform combined with the reverse Polish notation algorithm is developed. To gain the accurate simulation results, the discrete motor model and IPM model are built to deal with the dead-time.Based on the simulation system, parameter identification can be implemented and control parameters can be optimized by using the exhaust algorithm. The parameters obtained by the simulation system were successfully applied to an experimental system, and the favorable control performance was achieved.

  14. Wireless transmission of power and information through one high frequency resonant AC link inverter for robot manipulator applications

    A contact-less decentralized power supply is proposed with communication capability through only one transformer. A prototype of wireless transmission system of power and information (WTPI system) was built, and the two axis position control for servo motors was achieved by transferring the power and signal through one rotatable high frequency transformer. The proposed concept can be applied for robotics and NC machines

  15. Highly Efficient Contactless Electrical Energy Transmission System

    Ayano, Hideki; Nagase, Hiroshi; Inaba, Hiromi

    This paper proposes a new concept for a contactless electrical energy transmission system for an elevator and an automated guided vehicle. The system has rechargeable batteries on the car and electrical energy is supplied at a specific place. When electric power is supplied to the car, it runs automatically and approaches the battery charger. Therefore, a comparatively large gap is needed between the primary transformer at the battery charger and the secondary transformer on the car in order to prevent damage which would be caused by a collision. In this case, a drop of the transformer coupling rate due to the large gap must be prevented. In conventional contactless electrical energy transmission technology, since electric power is received by a pick-up coil from a power line, a large-sized transformer is required. And when the distance over which the car runs is long, the copper loss of the line also increases. The developed system adopts a high frequency inverter using a soft switching method to miniaturize the transformer. The system has a coupling rate of 0.88 for a transformer gap length of 10mm and can operate at 91% efficiency.

  16. Transmission System Performance Analysis for High-Penetration Photovoltaics

    Achilles, S.; Schramm, S.; Bebic, J.

    2008-02-01

    This study is an assessment of the potential impact of high levels of penetration of photovoltaic (PV) generation on transmission systems. The effort used stability simulations of a transmission system with different levels of PV generation and load.

  17. Power Delivery in Multiterminal VSC-HVDC Transmission System for Offshore Wind Power Applications

    Silva, Rodrigo Da; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    present three strategies in order to connect one offshore wind farm and two AC grids with different power ratings. The first strategy shows the easier case when one onshore station defines the power transmission and it is followed by the situation when droop control is applied. The final scheme is focused......This paper deals with one of the challenges in the field of offshore wind power systems: power transmission among the wind farms and the land when there is more than one AC grid to be considered. This case is known in the literature as multiterminal connection. The proposed studies are going to...... on the technique which a central power control is able to manage the onshore stations. The results are compared using EMTDCPSCAD platform....

  18. Prediction of solar induced currents and effects on power transmission systems in central Canada

    Goddard, W. R.; Boerner, W. M.

    1979-01-01

    The auroral-electrojet zone covers three quarters of Manitoba and consequently, solar storms strongly affect transmission lines. Harmonics are generated at transformers due to the saturation of their cores by induced currents, and the level of harmonics produced may cause malfunction of control relays, and yield unacceptable distortions in normal ac waveforms. The expected effects of long ac transmission systems were studied with emphasis on a 500 kv line to be built from Winnipeg to Minneapolis-St. Paul. Spectral analysis of induced current records from Manitoba Hydro's LaVerendrye station and magnetograms from IMS stations in Manitoba were used along with results of Campbell's work on the Alaskan pipeline induction problem (1978) in order to predict periodic and surge currents. It is concluded that the surge currents will produce significant levels of harmonics and corresponding operating problems during magnetic storms.

  19. An NPV and AC Analysis of a Stochastic Inventory System with Joint Manufacturing and Remanufacturing

    Laan, Erwin

    2000-01-01

    textabstractWhile the net present value (NPV) approach is widely accepted as the right framework for studying production and inventory control systems, average cost (AC) models are more widely used. For the well known EOQ model it can be veri_ed that (under certain conditions) the AC approach gives near optimal results. This paper investigates whether the same holds for two-source systems with joint manufacturing and remanufacturing. It appears that the performance of the AC approach stands o...

  20. Using Imperialist Competitve Algorithm for Secured loadability enhancement with TCSC in transmission system for pool and hybrid model

    Ehsan Afzalan

    2015-09-01

    Full Text Available This paper proposes an algorithm for the optimal location and control of Flexible AC Transmission System (FACTS devices for enhancing the loadability in transmission system using particle swarm optimization (PSO and Imperialist Competitve Algorithm (ICA for pool and hybrid model in deregulated electricity market. This approach uses AC load flow equations with the constraints on power generation, transmission line flow, magnitude of bus voltages and FACTS device settings. The bilateral transactions are modeled using secured bilateral transaction matrix utilizing AC distribution factor with the slack bus contribution. In this proposed approach, Thyristor Controlled Series Compensator (TCSC is used. To validate the proposed approach, simulations are performed on 39-bus New England test system and IEEE 118-bus system. Comparisons are made in terms of maximum loadability, computation time. The simulation results obtained indicate that by optimal location and control of TCSC, using ICA, the loadability in transmission system is enhanced and a less computation time is achieved. The comparative study concludes that by the optimal location and control of TCSC using ICA method the secured loadability enhancement is obtained in the transmission system in deregulated electricity market.

  1. Energy analysis of the basic materials utilized in electric power transmission systems

    1979-04-30

    The energy content per mile of installed underground and overhead power transmission systems has been calculated for the following types of systems: self-contained oil-filled cables; HPOF pipe-type cables; extruded dielectric cables; compressed-gas-insulated systems; overhead lines (ac and dc) and two proposed superconducting systems (ac and dc). The system operating voltages analyzed included 138, 230, 345, 500, 765 and 1,200 kV for ac systems, but all systems were not analyzed at the higher voltages. The dc overhead lines operated at +-200, +-400, +-600 and +-800 kV. Total installed energy content for these systems ranged from 4 x 10/sup 9/ to 1.2 x 10/sup 11/ Btu per mile. Installation energy requirements were generally 10% or less of the inherent system energy content based on the materials used in each system. Most of the energy content in each system can be attributed to the metallic components; plastic and insulating oil also contribute significantly. The energy content of 36 materials and basic products, in terms of Btu per ton, was calculated as part of this study. Substitution of conductor materials (e.g., aluminum for copper) in cable systems resulted in changes in the total system energy content on the order of 15%.

  2. Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

    Dinh, Minh-Chau, E-mail: thanchau7787@gmail.com [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of)

    2013-01-15

    Highlights: ► A model-sized superconducting VSC-HVDC system was designed and fabricated. ► A real-time simulation using Real Time Digital Simulator has been performed. ► The AC loss characteristics of HTS DC power cable caused by harmonics were analyzed. ► The AC loss of the HTS DC power cable will be used as a parameter to design the cable cooling system. -- Abstract: The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

  3. Fiber optic multiplex optical transmission system

    Bell, C. H. (Inventor)

    1977-01-01

    A multiplex optical transmission system which minimizes external interference while simultaneously receiving and transmitting video, digital data, and audio signals is described. Signals are received into subgroup mixers for blocking into respective frequency ranges. The outputs of these mixers are in turn fed to a master mixer which produces a composite electrical signal. An optical transmitter connected to the master mixer converts the composite signal into an optical signal and transmits it over a fiber optic cable to an optical receiver which receives the signal and converts it back to a composite electrical signal. A de-multiplexer is coupled to the output of the receiver for separating the composite signal back into composite video, digital data, and audio signals. A programmable optic patch board is interposed in the fiber optic cables for selectively connecting the optical signals to various receivers and transmitters.

  4. Insulation systems for superconducting transmission cables

    Tønnesen, Ole

    This paper describes shortly the status of superconducting transmission lines and assesses what impact the recently discovered BSCCO superconductors may have on the design of the cables.Two basically different insulation systems are discussed:1) The room temperature dielectric design, where the...... electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...... at temperature near 77 K.The optimal design is determined by a loss evaluation in relation to the power transfer capacity of the cable. Development work in progress on the design and construction of superconducting cables in Denmark is described as an example....

  5. Transmission Interference Improvement of Railway Communication via Distributed Antennas System.

    Lin, Siyu; Zhong , Zhangdui; Ai, Bo; Briso Rodriguez, Cesar

    2010-01-01

    Transmission interference is a key performance indicator of railway digital mobile communication system(RDMCS), whose performance will become worse in high-speed railway. The factors that influence the transmission interference of RDMCS are analyzed. Based on the relationship between speed and transmission interference, the scheme based on distributed antennas system (DAS) is proposed to improve transmission interference of RDMCS. The proposed scheme can reduce the collision probability betwe...

  6. Fuzzy-Wavelet Based Double Line Transmission System Protection Scheme in the Presence of SVC

    Goli, Ravikumar; Shaik, Abdul Gafoor; Tulasi Ram, Sankara S.

    2014-07-01

    Increasing the power transfer capability and efficient utilization of available transmission lines, improving the power system controllability and stability, power oscillation damping and voltage compensation have made strides and created Flexible AC Transmission (FACTS) devices in recent decades. Shunt FACTS devices can have adverse effects on distance protection both in steady state and transient periods. Severe under reaching is the most important problem of relay which is caused by current injection at the point of connection to the system. Current absorption of compensator leads to overreach of relay. This work presents an efficient method based on wavelet transforms, fault detection, classification and location using Fuzzy logic technique which is almost independent of fault impedance, fault distance and fault inception angle. The proposed protection scheme is found to be fast, reliable and accurate for various types of faults on transmission lines with and without Static Var compensator at different locations and with various incidence angles.

  7. Mathematical modeling of Automatic Control System (ACS) and synchronous motor in high reliability power supply systems in Kozloduy NPP - set up optimization of ACS

    The article presents the models of Automatic Control System (ACS) and synchronous motor of the reversible generator-engine groups of the first category power supply section in the Kozloduy NPP units 1 to 4. The control parameter is the magnetic field. The research aims are optimal ACS setups, property control guaranties in accordance with the technical requirements. The used synchronous machine model is included in Matlab5.x library. For optimization the instruments of optimization toolbox - NCD out port block and plant actuator and created basic models of variable Discrete PID-regulator and PWM system are utilized. The results are applied for the setup of the real ACS. The results precision of the created models gives a possibility for a real summary model development and the achieved models implementation in cases of fluctuations of AC/DC reversible electromechanical supply

  8. Mathematical modeling of Automatic Control System (ACS) and synchronous generator in high reliability power supply systems in Kozloduy NPP - set up optimization of ACS

    The article presents the models of Automatic Control System (ACS) and synchronous generator of the reversible generator-engine groups of first category power supply section in the Kozloduy NPP units 1 to 4. The control parameter is the synchronous machine tension. The research aims are optimal ACS setups, property control guaranties in accordance with the technical requirements. The used synchronous machine model is included in Matlab5.x library. For optimization the instruments of optimization toolbox - NCD out port block and plant actuator and created basic models of variable Discrete PID-regulator and PWM system are utilized. The results are applied for the setup of the real ACS. The results precision of the created models gives a possibility for a real summary model development and the achieved models implementation in cases of fluctuations of AC/DC reversible electromechanical supply

  9. On two-liquid AC electroosmotic system for thin films.

    Navarkar, Abhishek; Amiroudine, Sakir; Demekhin, Evgeny A

    2016-03-01

    Lab-on-chip devices employ EOF for transportation and mixing of liquids. However, when a steady (DC) electric field is applied to the liquids, there are undesirable effects such as degradation of sample, electrolysis, bubble formation, etc. due to large magnitude of electric potential required to generate the flow. These effects can be averted by using a time-periodic or AC electric field. Transport and mixing of nonconductive liquids remain a problem even with this technique. In the present study, a two-liquid system bounded by two rigid plates, which act as substrates, is considered. The potential distribution is derived by assuming a Boltzmann charge distribution and using the Debye-Hückel linearization. Analytical solution of this time-periodic system shows some effects of viscosity ratio and permittivity ratio on the velocity profile. Interfacial electrostatics is also found to play a significant role in deciding velocity gradients at the interface. High frequency of the applied electric field is observed to generate an approximately static velocity profile away from the Electric Double Layer (EDL). PMID:26773725

  10. System Frequency as Information Carrier in AC Power Systems

    Douglass, Philip James; Heussen, Kai; You, Shi;

    2015-01-01

    -DER) using changes to frequency setpoint values of genera- tors. Signaling discrete system states by generating off-nominal system frequency values can be used as a novel narrowband unidirectional broadcast communications channel. This paper describes two protocols for utilizing off-nominal frequencies...... to carry information: First, a protocol for dispatching blocks of FS- DER that is suitable for systems restricted to relatively slow rates of change of frequency (ROCOF). Second, for systems that allow higher ROCOF values, the feasibility of using power generation resources as a power line communication...... is shown with laboratory tests of a 20 kVA inverter. The inverter was found to have a maximum ROCOF of 2.2 Hz/s, sufficient to enable its use as a power line communication transmitter...

  11. Electricity transmission line planning: Success factors for transmission system operators to reduce public opposition

    Perras, Stefan

    2015-01-01

    Europe requires significant transmission grid expansions to foster the integration of electricity markets, enhance security of supply and integrate renewable energies. However, next to lengthy authorization processes, transmission system operators (TSOs) in Europe are currently facing extreme public opposition in their transmission line projects leading to significant project delays. These delays imply significant additional costs for TSOs as well as society as a whole and put the transformat...

  12. Commercial information system of Slovak Electricity Transmission System, Plc

    Commercial Information System (CIS), which main role of is to support the commercial activities of the company, is built up by business department of SEPS, Plc in close co-operation with the supplier company Sfera, Plc. The system entries are data from electricity meters obtained by automatized data acquisition and from bugging sheets, contractual hour diagrams, parameters of transmission system like measuring schemes and formulas for calculation of demand and supply, contractual data resulting from agreements, business conditions, URSO decisions and valid legislative. A part of the system is also support of process of data evaluation like calculation of transmitted energy quantity, calculation of actual output diagrams, comparison of actual and contractual diagrams, calculation of system divergence, calculation of demand divergence, etc. The final price for the drawings of services, which are joined with transmission of the electric power will be determined by the accounting process. In this causality there are automatically made out invoices for access, losses, system charges, system services, short-term and long-term transits, divergences and for cross-border transmission auctions. System also generates various specialized synopses and statistics for the evaluation requirements of important aspects and for parameter observations. Successive liberalisation of the electricity power market, changes in legislative and URSO decisions require CIS to be sufficiently configurable and to adapt flexible on the alternating environs. (author)

  13. BC energy plan II and transmission system planning

    The British Columbia Energy Plan involves Transmission and System planning. B C Transmission corporation is a Crown Corporation. The Energy Plan is based on energy security, energy conservation, environmental leadership and innovation in energy. The implications for transmission are connection to the general development, grid optimization, conservation, innovation and reliability standards

  14. Calculation of the Induced Voltage and Current for a Human and an Object Close to 765 kV AC Double Circuit Transmission Line

    Min, Suk Won [Soonchungyang University (Korea, Republic of); Kim, Eung Sik [Hoseo University (Korea, Republic of); Myeong Sung Ho; Lee, Byeong Yoon; Park, Jong Keun [Seoul National University (Korea, Republic of)

    1994-07-01

    This paper calculates the induced voltage and current for a human and a car under 765 kV AC double circuit transmission line. A human and a car is simulated as two dimension by the use of charge simulation method and as three dimension by using surface charge method. The phase arrangement of transmission line is varied to calculate the induced voltage and current. In two cases a human and a car is grounded or floated, the induced voltage and current is also compared. (author). 8 refs., 4 figs., 16 tabs.

  15. An NPV and AC Analysis of a Stochastic Inventory System with Joint Manufacturing and Remanufacturing

    E.A. van der Laan (Erwin)

    2000-01-01

    textabstractWhile the net present value (NPV) approach is widely accepted as the right framework for studying production and inventory control systems, average cost (AC) models are more widely used. For the well known EOQ model it can be veri_ed that (under certain conditions) the AC approach gives

  16. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    ZHUKOVYTSKYY I.V.; KLIUSHNYK I.A.; OCHKASOV O.B.; KORENIYK R.O.

    2015-01-01

    Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of...

  17. A Simulator Study of Recovery of HVDC Links Following AC System Faults

    J. Senthil; Padiyar, KR; Sachchidanand, *

    1990-01-01

    This paper presents the simulator study of a two-terminal HVDC system. The various AC system faults to which the study system is subjected are a) remote-three-phase ground fault, b)single-phase-ground fault and three phase ground faults. These faults are applied both at the rectifier and inverter ends. The results of the simulator study are presented to demonstrate the controller performance in the recovery of HVDC link following AC system faults.

  18. Research on closed-loop simulation system for digital AC servo system

    2009-01-01

    An intelligent and efficient closed-loop simulation system without any hardware is proposed for AC servo system.According to the characteristics of AC servo system and its control processor,the code executing platform combined with the reverse Polish notation algorithm is developed.To gain the accurate simulation results,the discrete motor model and IPM model are built to deal with the dead-time.Based on the simulation system,parameter identification can be implemented and control parameters can be optimized by using the exhaust algorithm.The parameters obtained by the simulation system were successfully applied to an experimental system,and the favorable control performance was achieved.

  19. An embedded Video Transmission System Based on H.264

    GAO Jing-min; LAN Ya-zhu

    2009-01-01

    In this paper,an embedded Video Transmission System based on H.264 is proposed.In this system,the latest video compression standards-H.264 is used as video codec algorithm,the i.mx27 is used as the center processors of the system,embedded Linux is used as the operating system and RTP/UDP is used as the network transmission protocol.The paper introduces the design way and the frame of the system.The test results of the system show that the proposed system can support good quality transmission of the video information.The parameters with the transmission are D1,720*480,30fps and 4Mbps.In addition,in order to ensure the security of the video information in the transmission,the system provides the encryption to the information in the process of compressing.

  20. Comparative Study of AC/DC High Voltage Transmissions%高压交直流输电比较研究

    王红刚

    2011-01-01

    比较了高压交流输电和高压直流输电的差异,认为,输送同样的电能,高压直流输电损耗少的原因在于载流子在晶格势场中的能态低;由于载流子受到感应电场的作用,高压交流输电载流子在晶格势场中的能态将高于高压直流输电载流子的能态。不论高压交流输电还是高压直流输电都存在着趋肤效应,直流趋肤效应起源于载流子受到的霍尔电场力;交流趋肤效应起源于载流子除了受到霍尔电场力外,还受到了交变电场力的作用.%Comparing the differences between AC and DC high voltage transmissions,it is considered that the reason why the DC high voltage transmission has lower electrical loss in transmitting the same power is that its carriers have low energy state in lattice potential field.As the carriers being affected by induced electric field,carriers of AC will have higher energy state than that of DC in lattice potential field.No matter AC or DC high voltage transmission there is skin effect.The DC skin effect originates from Hall electric field force acting on the carriers,while the AC skin effect originates from not only Hall electric field,but the role of alternating electric field force.

  1. Transmission techniques for emergent multicast and broadcast systems

    da Silva, Mario Marques; Dinis, Rui; Souto, Nuno; Silva, Joao Carlos

    2010-01-01

    Describing efficient transmission schemes for broadband wireless systems, Transmission Techniques for Emergent Multicast and Broadcast Systems examines advances in transmission techniques and receiver designs capable of supporting the emergent wireless needs for multimedia broadcast and multicast service (MBMS) requirements. It summarizes the research and development taking place in wireless communications for multimedia MBMS and addresses the means to improved spectral efficiency to allow for increased user bit rate, as well as increased capacity of the digital cellular radio network.The text

  2. 7 CFR 400.209 - Electronic transmission and receiving system.

    2010-01-01

    ... Contract-Standards for Approval § 400.209 Electronic transmission and receiving system. Any Contractor under the Contract is required to: (a) Adopt a plan for the purpose of transmitting and receiving... 7 Agriculture 6 2010-01-01 2010-01-01 false Electronic transmission and receiving system....

  3. 47 CFR 73.875 - Modification of transmission systems.

    2010-10-01

    ... transmission system facilities. (a) The following changes are prohibited: (1) Those that would result in the.... (2) Those that would cause the transmission system to exceed the equipment performance measurements... test operations at the full authorized ERP may commence immediately upon installation pursuant to §...

  4. Frequency support among asynchronous AC systems through VSCs emulating power plants

    Papangelis, Lampros; Guillaud, Xavier; Van Cutsem, Thierry

    2015-01-01

    This paper proposes a new control scheme for the Voltage Source Converters (VSCs) of a High Voltage Direct Current (HVDC) grid connecting asynchronous AC systems, so that the latter can mutually support their frequencies after a disturbance. The scheme involves no communication between VSCs. It is activated upon detection of a significant frequency deviation, with the possibility to limit the support requested from other AC systems. It relies on an integral control enforcing the frequency dro...

  5. A New Simulator for HVdc/ac Systems-Part I

    ZANGENEH, B. Zohouri; SHOULAIE, A.

    2003-01-01

    A simulator with optimal step time (SOST) has been designed to investigate Large HVdc/ac systems. The adequacy and robustness of the simulator will be demonstrated by showing some important applications relevant to operation, operational planning and medium-term planing. Some of the features of our SOST simulator are optimal step time algorithm, interpolation, chatter removal, MATLAB interface, unlimited size of ac system, and Farsi command that help model complex power electronic ci...

  6. Fault ride-through and grid support of permanent magnet synchronous generator-based wind farms with HVAC and VSC-HVDC transmission systems

    Liu, Hongzhi; Chen, Zhe

    2012-01-01

    This paper describes fault ride-through and grid support of offshore wind farms based on permanent magnet synchronous generator (PMSG) wind turbines connected to the onshore AC network through two alternative transmission systems: high voltage AC (HVAC) or high voltage DC (HVDC) based on voltage...... source converters (VSC). The proposed configurations of the PMSG-based offshore wind farm and VSC-based HVDC are given as well as their control strategies under both steady state and fault state. The PMSG-based offshore wind farm is integrated into a test power transmission system via either HVAC or VSC...

  7. Nonlinear system guidance in the presence of transmission zero dynamics

    Meyer, G.; Hunt, L. R.; Su, R.

    1995-01-01

    An iterative procedure is proposed for computing the commanded state trajectories and controls that guide a possibly multiaxis, time-varying, nonlinear system with transmission zero dynamics through a given arbitrary sequence of control points. The procedure is initialized by the system inverse with the transmission zero effects nulled out. Then the 'steady state' solution of the perturbation model with the transmission zero dynamics intact is computed and used to correct the initial zero-free solution. Both time domain and frequency domain methods are presented for computing the steady state solutions of the possibly nonminimum phase transmission zero dynamics. The procedure is illustrated by means of linear and nonlinear examples.

  8. MIMO Identical Eigenmode Transmission System (IETS) - a Channel Decomposition Perspective

    Shakir, Muhammad Zeeshan; Durrani, Tariq

    2007-01-01

    In the past few years considerable attention has been given to the design of Multiple-Input Multiple-Output (MIMO) Eigenmode Transmission Systems (EMTS). This paper presents an in-depth analysis of a new MIMO eigenmode transmission strategy. The non-linear decomposition technique called Geometric Mean Decomposition (GMD) is employed for the formation of eigenmodes over MIMO flatfading channel. Exploiting GMD technique, identical, parallel and independent transmission pipes are created for dat...

  9. Strategic Generation with Conjectured Transmission Price Responses in a Mixed Transmission Pricing System. Part 2. Application

    The conjectured transmission price response model presented in the first of this two-paper series considers the expectations of oligopolistic generators regarding how demands for transmission services affect the prices of those services. Here, the model is applied to northwest Europe, simulating a mixed transmission pricing system including export fees, a path-based auction system for between-country interfaces, and implicit congestion-based pricing of internal country constraints. The path-based system does not give credit for counterflows when calculating export capability. The application shows that this no-netting policy can exacerbate the economic inefficiencies caused by oligopolistic pricing by generators. The application also illustrates the effects of different generator conjectures regarding rival supply responses and transmission prices. If generators anticipate that their increased demand for transmission services will increase transmission prices, then competitive intensity diminishes and energy prices rise. In the example here, the effect of this anticipation is to double the price increase that results from oligopolistic (Cournot) competition among generators

  10. Strategic Generation with Conjectured Transmission Price Responses in a Mixed Transmission Pricing System. Part 1. Formulation

    The conjectured supply function (CSF) model calculates an oligopolistic equilibrium among competing generating companies (GenCos), presuming that GenCos anticipate that rival firms will react to price increases by expanding their sales at an assumed rate. The CSF model is generalized here to include each generator's conjectures concerning how the price of transmission services (point-to-point service and constrained interfaces) will be affected by the amount of those services that the generator demands. This generalization reflects the market reality that large producers will anticipate that they can favorably affect transmission prices by their actions. The model simulates oligopolistic competition among generators while simultaneously representing a mixed transmission pricing system. This mixed system includes fixed transmission tariffs, congestion-based pricing of physical transmission constraints (represented as a linearized dc load flow), and auctions of interface capacity in a path-based pricing system. Pricing inefficiencies, such as export fees and no credit for counterflows, can be simulated. The model is formulated as a linear mixed complementarity problem, which enables very large market models to be solved. In the second paper of this two-paper series, the capabilities of the model are illustrated with an application to northwest Europe, where transmission pricing is based on such a mixture of approaches

  11. Underwater Acoustic Image Transmission System Based on DSP

    Cheng En; Xu Ru

    2002-01-01

    The underwater acoustic image transmission system based on the high-speed DSP device TMS320C549 has been studied. We use Goertzel algorithm for source decoding and MFSK for modulation. Turbo code is used for channel coding and decoding. The purpose is to implement underwater video image data transmission.

  12. HVDC power transmission technology assessment

    Hauth, R.L.; Tatro, P.J.; Railing, B.D. [New England Power Service Co., Westborough, MA (United States); Johnson, B.K.; Stewart, J.R. [Power Technologies, Inc., Schenectady, NY (United States); Fink, J.L.

    1997-04-01

    The purpose of this study was to develop an assessment of the national utility system`s needs for electric transmission during the period 1995-2020 that could be met by future reduced-cost HVDC systems. The assessment was to include an economic evaluation of HVDC as a means for meeting those needs as well as a comparison with competing technologies such as ac transmission with and without Flexible AC Transmission System (FACTS) controllers. The role of force commutated dc converters was to be assumed where appropriate. The assessment begins by identifying the general needs for transmission in the U.S. in the context of a future deregulated power industry. The possible roles for direct current transmission are then postulated in terms of representative scenarios. A few of the scenarios are illustrated with the help of actual U.S. system examples. non-traditional applications as well as traditional applications such as long lines and asynchronous interconnections are discussed. The classical ``break-even distance`` concept for comparing HVDC and ac lines is used to assess the selected scenarios. The impact of reduced-cost converters is reflected in terms of the break-even distance. This report presents a comprehensive review of the functional benefits of HVDC transmission and updated cost data for both ac and dc system components. It also provides some provocative thoughts on how direct current transmission might be applied to better utilize and expand our nation`s increasingly stressed transmission assets.

  13. Control of MTDC Transmission Systems under Local Information

    Andreasson, Martin; Dimarogonas, Dimos V.; Sandberg, Henrik; Johansson, Karl H.

    2014-01-01

    High-voltage direct current (HVDC) is a commonly used technology for long-distance electric power transmission, mainly due to its low resistive losses. In this paper a distributed controller for multi-terminal high-voltage direct current (MTDC) transmission systems is considered. Sufficient conditions for when the proposed controller renders the closed-loop system asymptotically stable are provided. Provided that the closed loop system is asymptotically stable, it is shown that in steady-stat...

  14. FPGA Implementation of Video Transmission System Based on LTE

    Lu Yan; Zhang Qianlong; Tang An

    2015-01-01

    In order to support high-definition video transmission, an implementation of video transmission system based on Long Term Evolution is designed. This system is developed on Xilinx Virtex-6 FPGA ML605 Evaluation Board. The paper elaborates the features of baseband link designed in Xilinx ISE and protocol stack designed in Xilinx SDK, and introduces the process of setting up hardware and software platform in Xilinx XPS. According to test, this system consumes less hardware resource and is able ...

  15. Determination of Transmission Limits on Electric Power Systems

    Castellanos-Bustamante Rafael

    2014-04-01

    Full Text Available This article provides the application of several methodologies to obtain power transmission limits through interties of the electric power systems to obtain a secure operation of the energy power system. Several aspects to obtain the maximum power flows of electrical energy thought of transmission lines on electrical grids are shown. Thermal limit of electrical conductors, loadability limit of transmission lines and small signal stability limits are obtained for several interties between geographical regions. It also, shows the application of a load shedding scheme to stabilize an interarea oscillation mode. The model of the Mexican Interconnected power System is used to illustrate these methodologies.

  16. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    I. V. Zhukovytskyy

    2015-08-01

    Full Text Available Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of the diesel locomotive repair enterprises was analyzed. It is achieved based on a detailed review of existing foreign information-measuring test systems for hydraulic transmission of diesel locomotives, BelAZ earthmover, aircraft tug, slag car, truck, BelAZ wheel dozer, some brands of tractors, etc. The problem for creation the information-measuring test systems for diesel locomotive hydraulic transmission is being solved, starting in the first place from the possibility of automation of the existing test stand of diesel locomotives hydraulic transmission at Dnipropetrovsk Diesel Locomotive Repair Plant "Promteplovoz". Methodology. In the work the researchers proposed the method to create a microprocessor automated system of diesel locomotives hydraulic transmission stand testing in the locomotive plant conditions. It acts by justifying the selection of the necessary sensors, as well as the application of the necessary hardware and software for information-measuring systems. Findings. Based on the conducted analysis there was grounded the necessity of improvement the plant hydraulic transmission stand testing by creating a microprocessor testing system, supported by the experience of developing such systems abroad. Further research should be aimed to improve the accuracy and frequency of data collection by adopting the more modern and reliable sensors in tandem with the use of filtering software for electromagnetic and other interference. Originality. The

  17. Power electronics in electric utilities: HVDC power transmission systems

    Nozari, F.; Patel, H.S.

    1988-04-01

    High Voltage Direct Current (HVDC) power transmission systems constitute an important application of power electronics technology. This paper reviews salient aspects of this growing industry. The paper summarizes the history of HVDC transmission and discusses the economic and technical reasons responsible for development of HVDC systems. The paper also describes terminal design and basic configurations of HVDC systems, as well as major equipments of HVDC transmission system. In this regard, the state-of-the-art technology in the equipments constructions are discussed. Finally, the paper reviews future developments in the HVDC transmission systems, including promising technologies, such as multiterminal configurations, Gate Turn-Off (GTO) devices, forced commutation converters, and new advances in control electronics.

  18. EHV/HV Underground Cable Systems for Power Transmission

    Bak, Claus Leth

    Power transmission is facing its largest challenges ever with regards to handling a transition from today’s fossil‐based power production into renewable sources of generation. We can no longer place power plants close to centres of consumption; they must be located where the natural resources are...... to be found. One very good example of this is offshore wind power plants. The current transmission system is laid out in a traditional manner, which is based on the idea of not transporting power over longer distances as the power plants have been located near centres of consumption. It has merely...... layout of the transmission system must be re‐thought in order to accommodate the transmission needs for the future. New lines have to be constructed. Transmission lines are usually laid out as overhead lines, which are large structures, i.e. a 400 kV power pylon is 50 meters high. According to public...

  19. Marketing information system online design for craftsmen small medium enterprises (case study: craftsmen ac)

    Fitriana, Rina; Kurniawan, Wawan; Barlianto, Anung; Adriansyah Putra, Rizki

    2016-02-01

    AC is small and medium enterprises which is engaged in the field of crafts. This SME (Small Medium Enterprise) didn't have an integrated information system for managing sales. This research aims to design a marketing Information system online as applications that built as web base. The integrated system is made to manage sales and expand its market share. This study uses a structured analysis and design in its approach to build systems and also implemented a marketing framework of STP (Segmentation, Targeting, Positioning) and 4P (Price, Product, Place, Promotion) to obtain market analysis. The main market target customer craftsmen AC is women aged 13 years to 35 years. The products produced by AC are shoes, brooch, that are typical of the archipelago. The prices is range from Rp. 2000 until Rp. 400.000. Marketing information system online can be used as a sales transaction document, promoting the goods, and for customer booking products.

  20. Development of an electric power conversion system using a high frequency AC insulating link system. Koshuha AC zetsuen link hoshiki wo mochiita denryoku henkan system no kaihatsu

    1991-05-10

    An electric power convertion system incorporating a cycloconverter type high frequency AC insulating link system of which object was the dispersed power sources of 5KVA class was experimentally developed to evaluate the properties of the developed equipment. The system was composed of a cycloconverter which converted the frequency from 20kHz to 60Hz directly by converting DC to high frequency AC at the 20kHz high frequency inverter, and then by connecting to a high frequency transformer which insulated between the inputting side and the outputting circuit. The multi-functional hybrid IC technology where semiconductor elements, driving circuits, current detecting elements and overcurrent cut-off circuits were incorporated into a module, was introduced. As a result, the size of the high frequency transformer became one-tenth or less the size of transformer using commercial frequency and the weight reduced to about one-twentyfifth. When the commutation of high frequency power source and the forced gate commutation were used jointly, the efficiency was improved by 10 percentage at the 100 percentage load, compared with the case using only the forced gate commutation and the efficiency of mounted equipment was 90 percentage. 3 figs.

  1. Forward error correction in DWDM fiber-optic transmission system

    Gol, V. D.; Tsmykal, E. K.

    2009-01-01

    In this paper we consider options of antinoise coding application in DWDM fiber-optic transmission systems, and also we represent comparative analysis of predicting correction, defining by G.975.1 recommendation regarding correction possibility and redundancy.

  2. Italian power transmission systems. Decision making and operations

    The models adopted in Italy for management maintenance and development of national transmission system foresee a manager with a decision making rule and owners who operate physically on the electric power network

  3. Vibration transmissibility characteristics of smart spring vibration isolation system

    倪德; 朱如鹏; 陆凤霞; 鲍和云; 付秋菊

    2014-01-01

    The objective of this work was to study the vibration transmissibility characteristics of the undamped and damped smart spring systems. The frequency response characteristics of them were analyzed by using the equivalent linearization technique, and the possible types of the system motion were distinguished by using the starting and ending frequencies. The influences of system parameters on the vibration transmissibility characteristics were discussed. The following conclusions may be drawn from the analysis results. The undamped smart spring system may simultaneously have one starting frequency and one ending frequency or only have one starting frequency, and the damped system may simultaneously have two starting frequencies and one ending frequency. There is an optimal control parameter to make the peak value of the vibration transmissibility curve of the system be minimum. When the mass ratio is far away from the stiffness ratio, the vibration transmissibility is small. The effect of the damping ratio on the system vibration transmissibility is significant while the control parameter is less than its optimal value. But the influence of the relative damping ratio on the vibration transmissibility is small.

  4. On the transmissibilities of nonlinear vibration isolation system

    Lu, Zeqi; Brennan, Michael J.; Chen, Li-Qun

    2016-08-01

    Transmissibility is a key parameter to quantify the effectiveness of a vibration isolation system. Under harmonic excitation, the force transmissibility of a linear vibration isolation system is defined as the ratio between the amplitude of the force transmitted to the host structure and the excitation force amplitude, and the displacement transmissibility is the ratio between the displacement amplitude of the payload and that of the base. For a nonlinear vibration isolation system, the force or the displacement responses usually have more frequency components than the excitation. For a harmonic excitation, the response may be periodic, quasi-periodic or chaotic. Therefore, the amplitude ratio cannot well define the transmissibility. The root-mean-square ratio of the response to the excitation is suggested to define the transmissibility. The significance of the modified transmissibility is highlighted in a nonlinear two-stage vibration isolation system consisting of two linear spring connected linear vibration isolators with two additional horizontal linear springs. Harmonic balance method (HBM) is applied to determine the responses with the fundamental and third harmonic. Numerical simulations reveal that chaos may occur in the responses. In both cases, the modified transmissibility works while the original definition cannot be applied to chaotic response.

  5. 40 Gb/s optical transmission systems

    Buxens Azcoaga, Alvaro Juan; Nielsen, Steen Krogh

    2003-01-01

    traditional Non Return to Zero (NRZ) or use of Tunable chromatic Dispersion Compensators (TDC). Two single channel TDCs are experimentally evaluated. The first one, based on temperature changes in a chirped fiber Bragg grating, allows to reduce significantly chromatic dispersion induced penalty in a series of...... application (maximum distance of 40 km) the maximum PMD coeficient allowed in the transmission fiber, 0.4 ps=pkm, is below the values defined by actual standards, 0.5 ps=pkm. The most promising PMD compensation methods are presented and their advantages and disadvantages are discussed. A PMD compensator based...... on a single fixed birefringent element is evaluated at 10 Gb/s and 40 Gb/s. It provides an improvement of at least a factor of two in the total PMD allowed in a link. However even when using the PMD compensator it is estimated that the maximum PMD coeficient in the fibers used in a five span link...

  6. Electrical power transmission system engineering analysis and design

    Gonen, Turan

    2011-01-01

    Although many textbooks deal with a broad range of topics in the power system area of electrical engineering, few are written specifically for an in-depth study of modern electric power transmission.Drawing from the author's 31 years of teaching and power industry experience, in the U.S. and abroad, Electrical Power Transmission System Engineering: Analysis and Design, Second Edition provides a wide-ranging exploration of modern power transmission engineering. This self-contained text includes ample numerical examples and problems, and makes a special effort to familiarize readers with vocabul

  7. Distributed Controllers for Multi-Terminal HVDC Transmission Systems

    Andreasson, Martin; Dimarogonas, Dimos V.; Sandberg, Henrik; Johansson, Karl H.

    2014-01-01

    High-voltage direct current (HVDC) is an increasingly commonly used technology for long-distance electric power transmission, mainly due to its low resistive losses. In this paper the voltage-droop method (VDM) is reviewed, and three novel distributed controllers for multi-terminal HVDC (MTDC) transmission systems are proposed. Sufficient conditions for when the proposed controllers render the equilibrium of the closed-loop system asymptotically stable are provided. These conditions give insi...

  8. Alternative electrical transmission systems and their environmental impact

    Schiefelbein, G.F.

    1977-08-01

    A general description is provided of electrical transmission systems as an aid in determining their environmental impacts. Alternating current, direct current, overhead systems, underground systems, and water crossings are treated. The cost, performance, reliability, safety, and environmental impact of these systems are compared.

  9. Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

    WANG Hua; LUO Jiarong; YUAN Qiping; XU Congdong

    2007-01-01

    AC operation with multiple full cycles has been successfully performed on the superconducting tokamak HT-7. In the experiment, it was discovered that the saturation of the transformer magnetic flux with DEF, a signal name, was one of key aspects that affected the AC operation. The conditions of DEF were examined through the DEF feedback control system. By controlling the working patterns of the subsystems, namely the poloidal field control system and density control system, it was guaranteed that DEF would remain in the non-saturated status.

  10. Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

    Wang, Hua; Luo, Jiarong; Yuan, Qiping; Xu, Congdong

    2007-02-01

    AC operation with multiple full cycles has been successfully performed on the superconducting tokamak HT-7. In the experiment, it was discovered that the saturation of the transformer magnetic flux with DEF, a signal name, was one of key aspects that affected the AC operation. The conditions of DEF were examined through the DEF feedback control system. By controlling the working patterns of the subsystems, namely the poloidal field control system and density control system, it was guaranteed that DEF would remain in the non-saturated status.

  11. Harmonic detection an AC excited generation system based on in-phase correlation filtering

    2002-01-01

    The paper reports results of investigation on the harmonic detection technique of a complicated power supply system such as an AC excited generation system, which has a variable fundamental frequency and low order harmonics with rich sub-harmonics whose frequencies are lower than the fundamental one. The in-phase correlation filtering technique, based on the frequency shifting principle, is proposed in this paper. Theoretical analysis and experimental results validate the effectiveness of this technique for the harmonic detections of AC excited generation systems.

  12. Design issues of the TF AC/DC converter for the ITER coil power supply system

    The ITER Toroidal Field (TF) coil system is composed of 18 series-connected superconductor coils (L=17.5 Henry), related protection circuits, and an AC/DC converter. The converter for the TF coil system is a 12-pulse and 2-quadrant converter with the two thyristor bridges connected in parallel through the inter-phase reactor. The rated current of the converter is 68 kA, and no-load output voltage is 900 V when 66 kV AC input is used. Because ITER is a pulse system that uses huge power during the pulse, there are additional critical issues in designing the AC/DC converters. In this study the following issues in designing the TF AC/DC converter are discussed to improve the characteristics of the TF coil system; - Fault current issues related with AC input voltage and operational scenario. - Junction temperatures during the faults and the thyristor numbers per an arm. - Efficient and reliable bypass method including resuming. - Protection sequence for the fault conditions. - Reactive power reduction method. - Estimation of the optimum inductance of the DC Reactor (DCR)

  13. Cost estimation of HVDC transmission system of Bangka's NPP candidates

    Liun, Edwaren; Suparman

    2014-09-01

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different.

  14. Considering system non-linearity in transmission pricing

    Oloomi-Buygi, M. [Power System Department, Shahrood University of Technology, Shahrood (Iran); Salehizadeh, M. Reza [Islamic Azad University, Fars College of Science and Research (Iran)

    2008-10-15

    In this paper a new approach for transmission pricing is presented. The contribution of a contract on power flow of a transmission line is used as extent-of-use criterion for transmission pricing. In order to determine the contribution of each contract on power flow of each transmission line, first the contribution of each contract on each voltage angle is determined, which is called voltage angle decomposition. To this end, DC power flow is used to compute a primary solution for voltage angle decomposition. To consider the impacts of system non-linearity on voltage angle decomposition, a method is presented to determine the share of different terms of sine argument in sine value. Then the primary solution is corrected in different iterations of decoupled Newton-Raphson power flow using the presented sharing method. The presented approach is applied to a 4-bus test system and IEEE 30-bus test system and the results are analyzed. (author)

  15. Combined operation of AC and DC distribution system with distributed generation units

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system. (authors)

  16. Electromechanical systems with transient high power response operating from a resonant ac link

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant ac link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control all four operating quadrants. Incorporating the ac link allows the converter in these systems to switch at the zero crossing of every half cycle of the ac waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed under contract to NASA.

  17. Phase noise in GNSS transmission / reception system

    Rebeyrol, Emilie; Macabiau, Christophe; Ries, Lionel; Issler, Jean-Luc; Bousquet, Michel; Boucheret, Marie-Laure

    2006-01-01

    Recently the GPSIIR-M and the experimental Galileo satellites (GIOVE-A) were launched making the first step in the orbit-validation of the GPS modernization system and of the Galileo system. The new signals generated by the GPSIIR-M satellite and the Galileo system require modulations which are more complex than the QPSK modulation used in the current GPS system. These new modulations could be a source of distortions for the received signal and require analyses and optimisation. Indeed, in th...

  18. Design study of an AC power supply system in JT-60SA

    In the initial research phase of JT-60SA, which is the International Thermonuclear Experimental Reactor (ITER) satellite Tokamak with superconducting toroidal and poloidal magnetic field coils, the plasma heating operation of 30 MW-60 s or 20 MW-100 s is planned for 5.5 MA single null divertor plasmas. To achieve this operation, AC power source of the medium voltage of 18 kV and ∼7 GJ has to be provided in total to the poloidal field coil power supplies and additional heating devices such as neutral beam injection (NBI) and electron cyclotron radio frequency (ECRF). In this paper, the proposed AC power supply system in JT-60SA was estimated from the view point of available power, and harmonic currents based on the standard plasma operation scenario during the initial research phase. This AC power supply system consists of the reused JT-60 power supply facilities including motor generators with flywheel, AC breakers, harmonic filters, etc., to make it cost effective. In addition, the conceptual design of the upgraded AC power supply system for the ultimate heating power of 41 MW-100 s in the extended research phase is also described.

  19. Unequal error protection system for robust video transmission

    2006-01-01

    With the development of multimedia communication services, robust video transmission over wireless environment poses many challenges. A new UEP_ BTC _ STBC _ OFDM system is proposed to provide unequal error protection for the source coded video stream in dispersive fading channel. The scheme concatenates the Block Turbo Code (BTC) with the Space-Time Block Code (STBC) for an OFDM system.With the proposed system, both the good error correcting capability of BTC and the concurrent large diversity gain characteristic of STBC can be achieved simultaneously with low encoding and decoding complexity. Furthermore, by combining with the data partition of H. 264 and different BTC codes, this system can guarantee high QoS control of video transmission. Simulation result shows that the proposed system outperforms other reported schemes and has good performance of video transmission.

  20. Optimisation of Video-Data Transmission in Telematic System

    Emilia Bubenikova; Peter Holecko; Rastislav Pirnik

    2013-01-01

    The goal of this paper is to analyse, define, and summarise the requirements on networks connecting telematic technologies based on Intelligent Transport Systems (ITS). The paper describes the methodics of setting and a general concept of technological networks interface based on available and applicable standards Focus is set on optimisation of data transmission in the form of a video-stream and its tunnelling through xDSL transmission technology. The implementation of the designed compres...

  1. Optimisation of video-data transmission in telematic system

    Bubeníková, Emília; Pirník, Rastislav; Holečko, Peter

    2013-01-01

    The goal of this paper is to analyse, define, and summarise the requirements on networks connecting telematic technologies based on Intelligent Transport Systems (ITS). The paper describes the methodics of setting and a general concept of technological networks interface based on available and applicable standards Focus is set on optimisation of data transmission in the form of a video-stream and its tunnelling through xDSL transmission technology. The implementation of the designed compressi...

  2. Electromechanical systems with transient high power response operating from a resonant AC link

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD).

  3. Modelling and control of hybrid renewable energy system connected to AC grid

    Sami Younsi

    2011-12-01

    Full Text Available This paper discusses the development of new control and supervision method for the optimum operation of hybrid renewable energy system (HRES connected to AC grid. The hybrid system consists of wind generator (WG, diesel generator (DG, and flywheel energy storage system (FESS. These subsystems are based on permanent magnet synchronous machines (PMSM which are controlled by sliding mode control. A supervisor control is designed to determine the energy transfer type of flywheel energy storage system (charging / discharging / no transfer energy, to take decision on diesel generators ON/OFF status, and to determine the reference powers for these two subsystems. The supervisor inputs are the power requested by AC grid, the power generated by wind generator, and the energy stored in flywheel. The objectives of the control and supervision for hybrid renewable energy system are to satisfy the power requested by AC grid, to manage the energy transfer between hybrid system and AC grid, to optimize the use of wind energy, and to reduce fuel of diesel generator. The system is simulated with Matlab – Simulink software and it gave good results.

  4. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    Gallegos-Lopez, Gabriel; Nagashima, James M.; Perisic, Milun; Hiti, Silva

    2012-06-05

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  5. Theoretical and experimental investigation into anti-idling A/C system for trucks

    Highlights: • A mathematical model is developed and verified using a built test-bed. • Thermal and performance characteristics of an anti-idling truck A/C system are investigated. • It is shown that variable speed fans have significant effects on the COP in different conditions. • A point of optimum COP can be found by changing the fans speed for any operating condition. • Anti-idling A/C systems equipped to variable speed control can significantly save environment. - Abstract: In this study, a recently developed truck anti-idling air conditioning (A/C) system is investigated. A mathematical model is developed to simulate the thermodynamic and heat transfer characteristics of the A/C system and calculate the coefficient of performance (COP). Utilizing environmental chambers and a number of measuring equipment, an experimental setup is built to verify the accuracy of the mathematical model and to perform a comprehensive study on the performance of the system for a wide range of operating conditions. A good agreement between the simulation and the experimental data, with a maximum discrepancy of 10.6%, is achieved. The results show a range of 0.5–1.7 for the system COP under a variety of operating condition. The parametric study shows that for any cooling demand, ambient and indoor air temperatures, there is a point of optimum COP that can be achieved by adjusting the condenser and evaporator fans speed

  6. Data transmission system with encryption by chaotic sequences

    Politans’kyy R. L.

    2014-06-01

    Full Text Available Protection of transferable information in the telecommunication systems is possible by its imposition of coding sequence on a plaintext. Encryption of pseudorandom sequences can be performed by using generation algorithms which are implemented on the basis of the phenomenon of dynamical chaos, which is sensitive to changes in the initial conditions. One of the major problems encountered in the construction of secure communication systems is to provide synchronization between the receiving and transmitting parties of communication systems. Improvement of methods of hidden data transfer based on the systems with chaotic synchronization is the important task of research in the field of information and telecommunication systems based on chaos. This article shows an implementation of a data transmission system, encrypted by sequences, generated on the basis of one-dimensional discrete chaotic maps with ensuring synchronization of the transmitting and receiving sides of the system. In this system realization of synchronization is offered by a transmission through certain time domains of current value of xn generated by a logistic reflection. Xn transmission period depends on computer speed and distance between subscribers of the system. Its value is determined by transmitting a test message before the session. Infallible reception of test message indicates the optimal choice of a transmission period of the current value of xn. Selection period is done at the program level. For the construction of communication network modern software was used, in particular programming language Delphi 7.0. The work of the system is shown on the example of information transmission between the users of the system. The system operates in real time full duplex mode at any hardware implementation of Internet access. It is enough for the users of the system to specify IP address only.

  7. FPGA Implementation of Video Transmission System Based on LTE

    Lu Yan

    2015-01-01

    Full Text Available In order to support high-definition video transmission, an implementation of video transmission system based on Long Term Evolution is designed. This system is developed on Xilinx Virtex-6 FPGA ML605 Evaluation Board. The paper elaborates the features of baseband link designed in Xilinx ISE and protocol stack designed in Xilinx SDK, and introduces the process of setting up hardware and software platform in Xilinx XPS. According to test, this system consumes less hardware resource and is able to transmit bidirectional video clearly and stably.

  8. Wireless OAM transmission system based on elliptical microstrip patch antenna.

    Chen, Jia Jia; Lu, Qian Nan; Dong, Fei Fei; Yang, Jing Jing; Huang, Ming

    2016-05-30

    The multiplexing transmission has always been a focus of attention for communication technology. In this paper, the radiation characteristics of circular microstrip patch antenna was firstly analyzed based on cavity model theory, and then spiral beams carrying orbital angular momentum (OAM) were generated, using elliptical microstrip patch antenna, with a single feed probe instead of a standard circular patch with two feedpoints. Moreover, by combining the proposed elliptic microstrip patch antenna with Universal Software Radio Peripheral (USRP), a wireless OAM transmission system was established and the real-time transmission of text, image and video in a real channel environment was realized. Since the wireless OAM transmission has the advantage of good safety and high spectrum utilization efficiency, this work has theoretical significance and potential application. PMID:27410080

  9. Creating a robust and integrated electrical transmission system

    The service territory for Puget Sound Energy (PSE) was presented in terms of electric power and gas transmission. Issues affecting the Puget Sound area include high growth and the west coast energy crisis which has had an adverse financial impact on the power industry. The transmission system is basically at capacity and has been impacted by imports and exports between the United States and Canada. Other issues include the separation between energy resources and transmission, modernizing the power grid, and challenges for independent power producers (IPPs). The Northwest Transmission Assessment Committee (NTAC), which was formed under the Northwest Power Pool, has the potential to bring interested parties to study constrained paths and to plan a single utility concept for the region. It is expected that new challenges such as financing and risk management will emerge once the technical solutions are identified and agreed upon. The issue of enforceable and mandatory reliability standards was also discussed. 1 fig

  10. Design of data transmission for a portable DAQ system

    Field Programmable Gate Array (FPGA), combined with ARM (Advanced RISC Machines) is increasingly employed in the portable data acquisition (DAQ) system for nuclear experiments to reduce the system volume and achieve powerful and multifunctional capacity. High-speed data transmission between FPGA and ARM is one of the most challenging issues for system implementation. In this paper, we propose a method to realize the high-speed data transmission by using the FPGA to acquire massive data from FEE (Front-end electronics) and send it to the ARM whilst the ARM to transmit the data to the remote computer through the TCP/IP protocol for later process. This paper mainly introduces the interface design of the high-speed transmission method between the FPGA and the ARM, the transmission logic of the FPGA, and the program design of the ARM. The theoretical research shows that the maximal transmission speed between the FPGA and the ARM through this way can reach 50 MB/s. In a realistic nuclear physics experiment, this portable DAQ system achieved 2.2 MB/s data acquisition speed. (authors)

  11. Investigation of multimodule buck–boost inverter-based HVDC transmission system

    Ahmed A. Elserougi

    2015-01-01

    Full Text Available In high voltage direct current (HVDC systems, the semiconductor devices have to be connected in series to obtain the required high-voltage ratings. This study proposes a new HVDC configuration, namely, multimodule buck–boost inverter for HVDC transmission applications which avoids series connection of large number of semiconductor switches. In addition, it provides a blocking capability against DC side faults. The proposed configuration consists of several simple buck–boost converters which are assembled together to meet the requirements of high-voltage high-power applications. This paper studies the dynamic performance of the proposed system under different operating conditions, and the results were satisfactory. The main advantages of the proposed configuration are: (i pure sinusoidal output which minimises/eliminates the requirements for supplementary AC filters and offers an inherent suppression to the common mode voltages, (ii very low dv/dt stresses and (iii complete blocking capability of AC side contributions during DC side faults. This study discusses the system architecture, passive components selections, voltage and current ratings of its semiconductor devices and the required controllers. A comparison between the proposed configuration and other existing HVDC technologies is also presented in this study.

  12. Model of Bi-directional Flyback Converter for Hybrid AC/DC Distribution System

    Riku Pasonen

    2013-01-01

    In this article, a simulation model and concept of two switch bi-directional isolated DC/DC converter is presented. Converter is based on flyback converter type. Also control method for voltage regulation with bi-directional power transfer is presented. Target application of the proposed converter was selected to be a hybrid AC/DC distribution system concept of which was briefly described. The requirement of galvanic isolation in the hybrid AC/DC concept comes from use of shared neutral wire;...

  13. Internal Heating of an IGBT module in a System With a Regenerative AC Drive

    Mabano, Michel

    2016-01-01

    The purpose of this thesis was to understand the internal heating of an IGBT module inside an AC drive in a system with a regenerative unit to it. During the implementation of the lab, various approaches were taken in an effort to collect measurements appropriate to the topic of investigation. The IGBT junction temperature was recorded over a sustained period of time at various speed of the induction motor. The braking torque applied through a second AC drive was varied in order to study...

  14. Model of Bi-directional Flyback Converter for Hybrid AC/DC Distribution System

    Riku Pasonen

    2013-12-01

    Full Text Available In this article, a simulation model and concept of two switch bi-directional isolated DC/DC converter is presented. Converter is based on flyback converter type. Also control method for voltage regulation with bi-directional power transfer is presented. Target application of the proposed converter was selected to be a hybrid AC/DC distribution system concept of which was briefly described. The requirement of galvanic isolation in the hybrid AC/DC concept comes from use of shared neutral wire; DC current runs with unbalanced part of AC current in neutral wire. Without galvanic isolation grounded neutral would cause short circuit if DC/DC converter is connected to three phase rectifier or inverter. Simulation was carried out with PSCAD electromagnetic transient simulator.

  15. Development of New Type Gap Arrester for Earth Fault Protection in AC Feeding System

    Ajiki, Kohji; Morimoto, Hiroaki; Hisamizu, Yasuzi; Kinoshita, Nobuo; Takai, Wataru; Sato, Ryogo

    A gap arrester is being used for ground fault protection in AC Feeding System. However there are faults in which a conventional gap arrester burns down in a normal state of circuit. We investigated the cause of the fault in which a gap arrester burns. Then, it was found out that the cause of the fault was the discharge of AC current from the surge voltage. Therefore, we developed a new type gap arrester which does not burn down. The new type gap arrester is composed of a discharge tube and a zinc oxide element which are connected in series. Unnecessary AC current discharge is prevented by this structure. The new type gap arrester is actually used at the railroad track.

  16. Research of pneumatic control transmission system for small irradiation samples

    In order to reduce the absorbed dose damage for the operator, pneumatic control has been adopted to realize the rapid transmission of small irradiation samples. On/off of pneumatic circuit and directions for the rapid transmission system are controlled by the electrical control part. The main program initializes the system and detects the location of the manual/automatic change-over switch, and call for the corresponding subprogram to achieve the automatic or manual operation. Automatic subprogram achieves the automatic sample transmission; Manual subprogram completes the deflation, and back and forth movement of the radiation samples. This paper introduces in detail the implementation of the system, in terms of both hardware and software design. (authors)

  17. Shift Control System of Heavy-duty Vehicle Automatic Transmission

    Yan Zhang; Wenxing Ma; Xuesong Li

    2013-01-01

    Heavy-duty vehicle hydrodynamic mechanical automatic transmission shifting operation system was designed, mathematical model of its simplified hydraulic system was established and simulation model of shifting operation system was established with AMESim, the simulation experiment was carried out, then oil pressure curves of each clutch hydraulic cylinder were obtained when giving forward gear or reverse gear signals. The simulation results show that shifting operating system meets the design ...

  18. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network w...

  19. A Series-LC-Filtered Active Damper for AC Power Electronics Based Power Systems

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang;

    2015-01-01

    This paper proposes an active damper with a series LC-filter for suppressing resonances in an ac power electronics based power system. The added filter capacitor helps to lower the voltage stress of the converter to be used for implementing the damper. Unlike active filters for the compensation of...

  20. Autonomous Active Power Control for Islanded AC Microgrids with Photovoltaic Generation and Energy Storage System

    Wu, Dan; Tang, Fen; Dragicevic, Tomislav; Vasquez, Juan Carlos; Guerrero, Josep M.

    2014-01-01

    In an islanded AC microgrid with distributed energy storage system (ESS), photovoltaic (PV) generation and loads, a coordinated active power regulation is required to ensure efficient utilization of renewable energy, while keeping the ESS from overcharge and over discharge conditions. In this pap...

  1. Status of Bulgarian electricity transmission system

    The reduced electricity consumption and exports from the country due to the ongoing economic crisis in the country and the region, combined with escalating priority electricity from renewable energy sources has led to decreased load of the conventional facilities. There is an excess of available capacity for electricity production mainly due to the contribution of renewable energy sources, making in some cases this surplus electricity non-marketable day-ahead and within the day. The electricity from renewable energy sources causes both technical and financial problems for local condensation plants. For the period 31.03.-04.04.2013, drastic deviations from the permitted limits for exchange in the Bulgarian electricity system have been observed. To avoid this, measures are implemented to limit the electricity production. Plan for development of the electricity network in Bulgaria for the period 2013 – 2022 has been developed. The plan includes a detailed development of the electricity network over the next ten years is planned and the investment needed are evaluated. The new plan presents forecast for the production and consumption capacity and energy balance, real-time management, short circuit currents and telecommunications infrastructure development

  2. Development of an advanced transmission line fault location system

    This paper describes the solution techniques, system modeling considerations, and simulation studies performed as a part of the development of an advanced transmission line fault location system (AFLS) intended for use on the New York Power Authority's system. The Power Authority's Moses-Adirondack 230 kV lines were selected as a test bed for the study. A reduced model of the transmission system around the Moses-Adirondack lines was developed, and a number of Electromagnetic Transients Program (EMTP) cases run to establish simulated voltage and current information as fed to the fault location system. Sensitivity studies were performed to investigate the impact of various system models, hardware features, and system conditions on fault location accuracy

  3. Electronic control system of a gamma ray transmission tomographer

    An equipment for gamma ray transmission tomographer was designed and constructed in the Higher Institute of Nuclear Sciences and Technology. The present work describes the associate electronics of this equipment and the software developed for the electronic system. The electronics based on 80c31 microcontroller, controls the collection of pulses sent by the gamma detector; storage and transmission of the information toward the personal computer through the serial port, and the movements of the table. The system allows three ways of control: manual, automatic without PC, and automatic with control from PC

  4. Stokes Space in Direct-Detection Data Transmission Systems

    Estaran Tolosa, Jose Manuel; Lu, Xiaofeng; Zibar, Darko;

    2015-01-01

    Stokes-based processing permits complete and phase-insensitive characterization of the field’s SOP, readily unlocking polarization diversity in transmission systems where DD is desired. We present an overview on Stokes notions and most recent achievements in this context.......Stokes-based processing permits complete and phase-insensitive characterization of the field’s SOP, readily unlocking polarization diversity in transmission systems where DD is desired. We present an overview on Stokes notions and most recent achievements in this context....

  5. Synchronization of uncertain chaotic systems using a single transmission channel

    Feng Yong [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); School of Electrical and Computer Engineering, Royal Melbourne Institute of Technology, Melbourne, VIC 3001 (Australia)], E-mail: feng.yong@ems.rmit.edu.au; Yu Xinghuo [School of Electrical and Computer Engineering, Royal Melbourne Institute of Technology, Melbourne, VIC 3001 (Australia)], E-mail: x.yu@rmit.edu.au; Sun Lixia [College of Electrical Engineering, Hohai University, Nanjing 210098 (China)], E-mail: sunlixia@hit.edu.cn

    2008-02-15

    This paper proposes a robust sliding mode observer for synchronization of uncertain chaotic systems with multi-nonlinearities. A new control strategy is proposed for the construction of the robust sliding mode observer, which can avoid the strict conditions in the design process of Walcott-Zak observer. A new method of multi-dimensional signal transmission via single transmission channel is proposed and applied to chaos synchronization of uncertain chaotic systems with multi-nonlinearities. The simulation results are presented to validate the method.

  6. Synchronization of uncertain chaotic systems using a single transmission channel

    This paper proposes a robust sliding mode observer for synchronization of uncertain chaotic systems with multi-nonlinearities. A new control strategy is proposed for the construction of the robust sliding mode observer, which can avoid the strict conditions in the design process of Walcott-Zak observer. A new method of multi-dimensional signal transmission via single transmission channel is proposed and applied to chaos synchronization of uncertain chaotic systems with multi-nonlinearities. The simulation results are presented to validate the method

  7. Flow diagram of the longitudinal and Hall conductivities in ac regime in the disordered graphene quantum Hall system

    We numerically study the behavior of σxy(ω) and σxx (ω) for graphene QHE system in the ac (frequency ω) domain. We interpret these conductivities with the dynamical scaling analysis. We also discuss the temperature flow of σxy(ω) — σxx(ω) diagram for graphene QHE system in the ac region.

  8. Digital Signal Processor System for AC Power Drivers

    Ovidiu Neamtu

    2009-10-01

    Full Text Available DSP (Digital Signal Processor is the bestsolution for motor control systems to make possible thedevelopment of advanced motor drive systems. The motorcontrol processor calculates the required motor windingvoltage magnitude and frequency to operate the motor atthe desired speed. A PWM (Pulse Width Modulationcircuit controls the on and off duty cycle of the powerinverter switches to vary the magnitude of the motorvoltages.

  9. HVDC transmission power conversion applications in power systems

    Kim, Chan-Ki; Jang, Gil-Soo; Lim, Seong-Joo; Lee, Seok-Jin

    2009-01-01

    HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference.  Combin

  10. Medical data transmission system for remote healthcare centres

    The main motivation of this project is to improve the healthcare centres equipment and human resources efficiency, enabling those centres for transmission of parameters of medical interest. This system facilitates remote consultation, in particular between specialists and remote healthcare centres. Likewise it contributes to the qualification of professionals. The electrocardiographic (ECG) and electroencephalographic (EEG) signals are acquired, processed and then sent, fulfilling the effective norms, for application in the hospital network of Cordoba Province, which has nodes interconnected by phone line. As innovative aspects we emphasized the low cost of development and maintenance, great versatility and handling simplicity with a modular design for interconnection with diverse data transmission media (Wi-Fi, GPRS, etc.). Successfully experiences were obtained during the acquisition of the signals and transmissions on wired LAN networks. As improvements, we can mention: energy consumption optimization and mobile communication systems usage, in order to offer more autonomy

  11. Impedance matching wireless power transmission system for biomedical devices.

    Lum, Kin Yun; Lindén, Maria; Tan, Tian Swee

    2015-01-01

    For medical application, the efficiency and transmission distance of the wireless power transfer (WPT) are always the main concern. Research has been showing that the impedance matching is one of the critical factors for dealing with the problem. However, there is not much work performed taking both the source and load sides into consideration. Both sides matching is crucial in achieving an optimum overall performance, and the present work proposes a circuit model analysis for design and implementation. The proposed technique was validated against experiment and software simulation. Result was showing an improvement in transmission distance up to 6 times, and efficiency at this transmission distance had been improved up to 7 times as compared to the impedance mismatch system. The system had demonstrated a near-constant transfer efficiency for an operating range of 2cm-12cm. PMID:25980873

  12. A miniaturized digital telemetry system for physiological data transmission

    Portnoy, W. M.; Stotts, L. J.

    1978-01-01

    A physiological date telemetry system, consisting basically of a portable unit and a ground base station was designed, built, and tested. The portable unit to be worn by the subject is composed of a single crystal controlled transmitter with AM transmission of digital data and narrowband FM transmission of voice; a crystal controlled FM receiver; thirteen input channels follwed by a PCM encoder (three of these channels are designed for ECG data); a calibration unit; and a transponder control system. The ground base station consists of a standard telemetry reciever, a decoder, and an FM transmitter for transmission of voice and transponder signals to the portable unit. The ground base station has complete control of power to all subsystems in the portable unit. The phase-locked loop circuit which is used to decode the data, remains in operation even when the signal from the portable unit is interrupted.

  13. Optimization Control of Bidirectional Cascaded DC-AC Converter Systems

    Tian, Yanjun

    reliability in bidirectional cascaded converter. This research work analyses the control strategies based on the topology of dual active bridges converter cascaded with a three phase inverter. It firstly proposed a dc link voltage and active power coordinative control method for this cascaded topology, and it...... can reduce dc link voltage fluctuations, enhancing the dc link voltage reliability in case of one sub converter failure. Then the bidirectional power flow effect is analyzed, and an important guide line is proposed for the design of the two stage cascaded converter system. Towards the different...... reduce the dc link voltage control system type number, which is capable to improve system stability. Afterwards, this dissertation comes up with the concept of front to end impedance control method for the two stage cascaded converter, and it can greatly improve the system stability. At last the thesis...

  14. Improving Scheduling of Data Transmission in TDMA Systems

    Timotheos Aslanidis

    2016-05-01

    Full Text Available In an era where communication has a most important role in modern societies, designing efficient algorithms for data transmission is of the outmost importance. TDMA is a technology used in many communication systems such as satellites and cell phones. In order to transmit data in such systems we need to cluster them in packages. To achieve a faster transmission we are allowed to preempt the transmission of any packet in order to resume at a later time. Such preemptions though come with a delay in order to setup for the next transmission. In this paper we propose an algorithm which yields improved transmission scheduling. This algorithm we call MGA. We have proven an approximation ratio for MGA and ran experiments to establish that it works even better in practice. In order to conclude that MGA will be a very helpful tool in constructing an improved schedule for packet routing using preemtion with a setup cost, we compare its results to two other efficient algorithms designed by researchers in the past.

  15. Control strategies for VSC-based HVDC transmission system

    Stan, Ana-Irina; Stroe, Daniel Ioan; Silva, Rodrigo Da

    2011-01-01

    the behavior of the developed VSC-based HVDC transmission system two study cases are carried out using MATLAB/Simulink. The results obtained from simulations show acceptable performances, of the proposed strategies, when changes in the reference parameters are considered. The active power flow between...

  16. Minimization of transmission cost in decentralized control systems

    Wang, S.-H.; Davison, E. J.

    1978-01-01

    This paper considers the problem of stabilizing a linear time-invariant multivariable system by using local feedback controllers and some limited information exchange among local stations. The problem of achieving a given degree of stability with minimum transmission cost is solved.

  17. Direct AC–AC grid interface converter for ocean wave energy system

    Highlights: • Novel power grid interface converter for ocean wave energy system. • Unlike conventional approach, generator output is directly converted into fixed frequency AC for synchronous connection. • High conversion efficient and power quality could be achieved. - Abstract: Ocean wave energy is very promising. However, existing systems are using rectifying circuits to convert variable voltage and variable frequency output of electric generator into DC voltage and then use grid-tied inverter to connect to the power grid. Such arrangement will not only reduce the overall efficient but also increase the cost of the system. A direct AC–AC converter is a desirable solution. In this paper, a six-switch AC–AC converter has been proposed as a single phase grid-connected interface. New switching scheme has been derived for the converter such that the virtual input AC–DC conversion and the output DC–AC conversion can be decoupled. State-space averaging model and pulse width modulation scheme have been derived for the converter. As the input and the output operations can be decoupled, two independent controllers have been designed to handle the input AC–DC regulation and the output DC–AC regulation. The proposed scheme demands for two separate duty ratios and novel switching scheme has been derived to realize the combined duty ratios in one switching cycle. Power regulation, harmonics elimination and power factor correction control algorithms have also been derived for the converter when it is connected to the supply grid. Experimental results of a small scale model are included to demonstrate the effectiveness of the proposed switching and control schemes

  18. System co-optimization in wireless receiver design with TrACS

    Ramesh, Chithrupa; Rusu, Ana; Ismail, Mohammed; Skoglund, Mikael

    2008-01-01

    System co-optimization of the analog receiver front end circuit and the digital baseband processing could enable receiver designs with lower power budgets, as the signal processing in the digital receiver is asymmetric across circuit topologies. This paper presents a simulation tool that could assist with such co-optimized designs. TrACS (Transceiver Architecture and Channel Simulator) is an RF/DSP co-simulator, capable of providing an application-specific system-level perspective to receiver...

  19. Harmonic Analysis of AC-DC Topologies and their Impacts on Power Systems

    Mukhtiar Ahmed Mahar; Muhammad Aslam Uqaili; Abdul Sattar Larik

    2011-01-01

    Power Electronic Converters are commonly used in different applications because of high efficiency and low cost. Due to latest advancement in semiconductor devices it is difficult to draw the boundaries for applications of power electronic topologies. These topologies are variable structure systems and generate harmonics during the operation which will affect the power quality when are connected to system network. Rectifier is a big family of converters and used when ac-dc conv...

  20. A reduction of proof complexity to computational complexity for $AC^0[p]$ Frege systems

    Krajicek, Jan

    2013-01-01

    We give a general reduction of lengths-of-proofs lower bounds for constant depth Frege systems in DeMorgan language augmented by a connective counting modulo a prime $p$ (the so called $AC^0[p]$ Frege systems) to computational complexity lower bounds for search tasks involving search trees branching upon values of maps on the vector space of low degree polynomials over the finite filed with $p$ elements.

  1. A development of ITV system for power transmission line monitoring

    Cho, Hong Keun; Kim, Seok Ku; Lee, Kwang Joong; Lee, Won Bin [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1995-12-31

    Transmission lines which are important to supply the electricity installed on the terrestrially severe site such as mountains needed to be monitored to prevent electric fault by snow accelerating, icing, tree contact, fire etc. Inspections by human patrol has been done but it seems not so efficient and satisfiable. To cope with this a transmission line monitoring system using industrial television and OPGW was developed and field trilled at the site. This paper describes about the optical video transceiver, video distributor and control devices (author).

  2. Renegotiated CBR transmission in interactive video-on-demand system

    Kamiyama, Noriaki; Li, Victor OK

    1997-01-01

    An Interactive Video-On-Demand (IVOD) system requires transmission bandwidth allocation for each user. Since the volume of data in each video frame is variable, dynamic bandwidth allocation is desirable. In this paper, a new scheme that dynamically determines required bandwidth based on the queue length at the viewers Set-Top Box (STB) is proposed. This method requires no pre-calculation, so it is easily applied to IVOD. The variance of the video transmission rate for each user is an importan...

  3. Influence of the iodide/iodine redox system on the self-discharge of AC/AC electrochemical capacitors in salt aqueous electrolyte

    Qamar Abbas

    2015-12-01

    Full Text Available Self-discharge (SD of AC/AC (AC=activated carbon electrochemical capacitors in aqueous solutions of lithium sulfate (Li2SO4 and lithium sulfate+iodide salts (Li2SO4+KI or Li2SO4+LiI was investigated at 24 °C and −40 °C after cell potential hold at values from 1 V to 1.6 V. At 24 °C, the cells exhibit lower SD in Li2SO4+KI than in Li2SO4, owing to the redox activity of the 2I−/I2 system which drives the positive AC electrode to operate in narrow potential range and display lower potential drop than in Li2SO4. At −40°C, the capacitors exhibit comparable and reduced SD both in Li2SO4+LiI and Li2SO4, whatever the holding cell potential. Three-electrode cell experiments demonstrate that, at −40 °C, hydrogen chemisorption is thermodynamically unfavored under negative polarization, while the activity of the 2I−/I2 redox system under positive polarization is only slightly reduced. As a consequence, the AC/AC cells in Li2SO4 exhibit a typical electrical double-layer performance at −40°C, whereas they still behave as hybrid ones in Li2SO4+LiI, with twice higher capacitance than in Li2SO4. The (Ui-Ut vs t1/2 plots demonstrate that SD is essentially controlled by diffusion at −40°C, suggesting that it originates from bulkier hydrated ions. Overall, in the investigated temperature range, the AC/AC capacitors in Li2SO4+LiI demonstrate low self-discharge and high capacitance, while being able to operate up to 1.6 V.

  4. Imports, exports, and Alberta's transmission system impact on price fluctuation

    The roles, responsibilities and objectives of ESBI, a private for-profit company, appointed by the Alberta Government to be the Independent Transmission Administrator in the province, is sketched, prior to a discussion of price volatility in electricity, Alberta interconnections, intertie issues, the economic theory and the reality impact on prices. Given that imports and exports constitute a relatively small proportion of total generation or load in Alberta, price volatility is considered to have been only minimally affected by imports/exports. In contrast, transmission constraints, i.e. the limits on physical capacity of the existing transmission system to accommodate all desired transactions, have significant impact on imports/exports. Factors underlying constraints and price volatility such as uncertainty of generation dispatch, leading to reduced interest to invest, which in turn leads to scarce capacity for imports/exports, and the actions required to reduce uncertainty and address other issues such as congestion management, tariff design and the creation of regional transmission organizations, are also discussed to provide further clarification of the issues. It is suggested that these and other related issues need to be resolved to provide the clarity around transmission access and the tools required to manage price fluctuations

  5. Life Cycle Assessment on a 765 kV Venezuelan Transmission System

    The demand to preserve the environment and form a sustainable development is greatly increasing in the recent decades all over the world, and this environmental concern is also merged in electrical power industry, resulting in many eco-design approaches in T and D industries. As a method of eco-design, Life Cycle Assessment (LCA) is a systematic tool that enables the assessment of the environmental impacts of a product or service throughout its entire life cycle, i.e. raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence. In T and D industries, LCA has been done for a lot of products individually, in order to see one product's environmental impacts and to seek for ways of improving its environmental performance. This eco-design for product approach is a rather well-developed trend, however, as only a single electrical product cannot provide the electrical power to users, electrical system consists of a huge number of components, in order to investigate system's environmental profile, the entire environmental profiles of different composing products has to be integrated systematically, that is to say, a system approach is needed. Under this philosophy, in this paper, an LCA using SimaPro (one kind of LCA software) is conducted on a whole Venezuelan 765 kV AC transmission system, which transmits 8000 MW hydro-electrical power through 760 km to this country's load centers, with total 7 substations, i.e. one sending end, 2 intermediate substations and 4 receiving ends. This LCA includes both transmission lines and substations, and then the environmental impacts of the whole transmission system are investigated. (authors)

  6. Enhancing the Capacity of the AC Distribution System Using DC Interlinks - A Step Towards Future DC Grid

    Chaudhary, Sanjay; Guerrero, Josep M.; Teodorescu, Remus

    2015-01-01

    , the dc grid interconnection also allows the introduction of a common storage system which can be shared by the connected ac feeders, and the dc grid connection to other renewable energy resources. The increased power handling capacity and improved voltage profile of the ac distribution feeder using...

  7. Load flow computations in hybrid transmission - distributed power systems

    Wobbes, E.D.; Lahaye, D.J.P.

    2013-01-01

    We interconnect transmission and distribution power systems and perform load flow computations in the hybrid network. In the largest example we managed to build, fifty copies of a distribution network consisting of fifteen nodes is connected to the UCTE study model, resulting in a system consisting of 5003 nodes. For this model, the Newton load flow model converges in seven iterations. Future work in this direction should allow to build even larger networks.

  8. Artificial Intelligence SVC Based Control of Two Machine Transmission System

    Reza Bayat; Hamed ahmadi

    2013-01-01

    The main target in this paper is to present, design fuzzy logic controller (FLC) applied to static var compensator (SVC) on two machine transmission system to improve transient stability and rapid damping oscillations of synchronous generators, when power generators sudden changes occur.stability that also played important role in power systems. static var compensator with fuzzy logic controller (SVCFLC) is a new control strategy can help improve transient stability.The effect of three phase...

  9. An evaluation of the Panasonic model UD513AC-1 Thermoluminescence Dosimetry system

    An evaluation of the Panasonic UD513AC-1 Thermoluminescence Dosimetry system was performed to determine the system's capabilities as a general purpose thermoluminescence dosimeter measuring device. The tests that were performed included a critique of the user's manual, delimitation of the operating parameters, the quality of construction, and an evaluation of the features that were unique to this system. The UD513AC-1 was found to be an adequate measuring device for most dosimetric applications. It was not well suited for experimental work with thermoluminescence materials due to a low sensitivity displayed by the photomultiplier tube to commonly used materials. The system was well constructed and did not suffer hardware failure during this research. Major attributes of the UD513AC-1 were automatic data storage, highly reproducible heating ramps, an excellent infrared light filter and a unique feature to a single phosphor unit, a dose determination function. Negative aspects of the system included a limited data manipulation capability within the controlling program, a poorly written user's manual, inadequate sensitivity on the part of the photomultiplier tube, and insufficient capability to adjust the hot N2 gas flow to desired levels

  10. 47 CFR 74.796 - Modification of digital transmission systems and analog transmission systems for digital operation.

    2010-10-01

    ... with all applicable transmission system requirements. (6) The licensee shall maintain with the station...) Subtract the value determined in the previous step from the authorized effective radiated power (“ERP”) of... ERP must be expressed in decibels above one kilowatt: ERP(dBk) = 10 log ERP(kW); (4) Convert the...

  11. Marginal cost calculation of energy production in hydro thermoelectric systems considering the transmission system

    The alternatives for calculation of energy marginal cost in hydroelectric systems, considering the transmission one, was analysed, including fundamental concepts; generation/transmission systems, represented by linear power flow model; production marginal costs in hydrothermal systems and computation aspects. (C.G.C.). 11 refs, 5 figs

  12. Prospects of long-distance HTS DC power transmission systems

    Continual improvement of technologies for the safe use of power resources is a key to sustainable development of a human society. In particular, high-temperature superconductivity (HTS) should be used to meet the growing needs of the electric-power industry. It is known that HTS power cables allow us to increase the level of transmitted energy to several GW at voltage of 66-110 kV. HTS power cables of a coaxial design are almost ideal non-polluting system shielding electromagnetic field. In the present work we have tried to analyze various configurations of HTS power transmission systems, estimate the cable transmission capacitance depending on distance, and characterize reliability and efficiency of the systems.

  13. Prospects of long-distance HTS DC power transmission systems

    Romashov, M. A.; Sytnikov, V. E.; Shakarian, Y. G.; Ivanov, Y. V.

    2014-05-01

    Continual improvement of technologies for the safe use of power resources is a key to sustainable development of a human society. In particular, high-temperature superconductivity (HTS) should be used to meet the growing needs of the electric-power industry. It is known that HTS power cables allow us to increase the level of transmitted energy to several GW at voltage of 66-110 kV. HTS power cables of a coaxial design are almost ideal non-polluting system shielding electromagnetic field. In the present work we have tried to analyze various configurations of HTS power transmission systems, estimate the cable transmission capacitance depending on distance, and characterize reliability and efficiency of the systems.

  14. Transmission dispatch and congestion management in open market systems

    Fang, Risheng

    This thesis is located in the domain of electricity supply industry restructuring. It deals with emerging issues, whose understanding is essential to advancing knowledge of open access transmission theory and proceeds to develop approaches for solving the transmission dispatch and congestion management problem. An overview of current trends and experiences in utility restructuring and the main models for restructuring, as well as the classifications of system operators, is first presented. A fully unbundled competitive electricity market model, called the bilateral/multilateral trades model, is then developed. A survey of current research in transmission dispatch and congestion management is included with discussion of transmission capacity and ancillary services. A methodology for the power dispatch problem in a structure dominated by bilateral and multilateral transmission contracts is presented. Group structures are mathematically formulated and explored and three basic types of curtailment strategies proposed for use by market participants. A more complex model is then developed, which takes into account the co-existence of bilateral and multilateral contracts with pool type dynamic supplies and demands based on bids and market clearing prices. An integrated dispatch strategy to reconcile all three types of transactions (bilateral, multilateral and pool) is then developed. Prioritization of electricity transactions and related curtailment strategies are explored and a mechanism for coordination between market participants to achieve additional economic advantages is described. A theory of security based rescheduling is presented in order to investigate the security-related aspects of operation in an unbundled and deregulated system. The impact of post-contingency corrective capability on optimal rescheduling results has been identified and the advantage of incorporating post-contingency corrective rescheduling into the objective function demonstrated. Finally

  15. Mathematical analysis of parameter maintenance in precision technological V and AC systems (rus

    Sotnikov A.G.

    2011-08-01

    Full Text Available Various industrial processes usually take place in the air and they require different parameters of air quality and accuracy of its maintenance.In present there are no rigorous analytical methods for reliable determination the actual accuracy of maintenance of air quality parameters on condition that they change orderly or stochastically. The harmonic analysis of exponents of periodical increase and decrease of parameters is proposed. It can be used for the estimation of fluctuations and precision of maintenance of various air quality parameters, first of all, in precision technological V and AC systems.Suggested method of temperature calculation under changing periodical heat load at the premises is illustrated by the example of high-precision V and AC system operating the area of grinding and test of optical devices.

  16. R and D of seismic emergency information transmission system

    The R and D Seismic Emergency Information Transmission System has been conducted involving the latest progress in earthquake engineering with regard to estimation techniques on the hypocenter, fault and earthquake motion parameters and in information technologies. This system is the disaster management system which consists of user site and disaster information center and is capable of mutual information transmission through Inter-Net and walkie-talkie. The concept of the disaster management system which is adaptable with DiMSIS (Disaster Management Spatial Information System) developed by professor Kameda et al. of Kyoto University has been established. Based on this concept, a prototype system has been developed. This system has following functions, (1) compatible application both in usual condition and emergency time, (2) the decentralized independence, and (3) the integration of space and time information. The system can estimate the earthquake motion information with 500 m square mesh in a local area and transmit in a few minutes. In the development of the system, seismometer network, surface soil database and amplification functions were prepared for the examination of system function. Demonstration against the Tokai area was carried out and the function was verified. (author)

  17. ABB ACS6000传动系统在热轧线的应用%Application of ABB ACS6000 Driver System in Hot-rolling Line

    孙坚; 王君艳

    2012-01-01

    宝钢股份特钢事业部热轧厂粗轧机同步电机主传动上应用了ACS6000中压变频传动系统,采用电力电子元件IGCT作为其功率元件.详细介绍了该变频系统的硬件结构、软件组成以及技术特点.%In the hot-rolling workshop of Baosteel Special branch, ABB ACS6000 medium voltage variable speed drive system is used for rough-rolling mill synchronous motor. This system is equipped with so called integrated gate commutated thyristors (ICCT) as its power element. Detailed described the hardware and software configuration, technical characteristic of the drive system.

  18. The transmission link of CAPS navigation and communication system

    2009-01-01

    The Chinese Area Positioning System (CAPS) is based on communication satellites with integrated capability, which is different from the Global Positioning System (GPS), the International Maritime Satellite Organization (Inmarsat) and so on. CAPS works at C-band, and its navigation information is not directly generated from the satellite, but from the master control station on the ground and transmitted to users via the satellite. The slightly inclined geostationary-satellite orbit (SIGSO) satellites are adopted in CAPS. All of these increase the difficulty in the design of the system and terminals. In this paper, the authors study the CAPS configuration parameters of the navigation master control station, information transmission capability, and the selection of the antenna aperture of the communication center station, as well as the impact of satellite parameters on the whole communication system from the perspective of the transmission link budget. The conclusion of availability of the CAPS navigation system is achieved. The results show that the CAPS inbound communication system forms a new low-data-rate satellite communication system, which can accommodate mass communication terminals with the transmission rate of no more than 1 kbps for every terminal. The communication center station should be configured with a large-aperture antenna (about 10-15 m); spread spectrum com- munication technology should be used with the spreading gain as high as about 40 dB; reduction of the satellite transponder gain attenuation is beneficial to improving the signal-to-noise ratio of the system, with the attenuation value of 0 or 2 dB as the best choice. The fact that the CAPS navigation system has been checked and accepted by the experts and the operation is stable till now clarifies the rationality of the analysis results. The fact that a variety of experiments and applications of the satellite communication system designed according to the findings in this paper have been

  19. An active damper for stabilizing power-electronics-based AC systems

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco;

    2014-01-01

    The interactions among the parallel grid-connected converters coupled through the grid impedance tend to result in stability and power quality problems. To address them, this paper proposes an active damper based on a high bandwidth power electronics converter. The general idea behind this proposal...... experimental tests on a three-converter-based setup are carried out. The results show that the active damper can become a promising way to stabilize the power-electronics-based ac power systems....

  20. Comparison of Two Autonomous AC-DC Converters for Piezoelectric Energy Scavenging Systems

    Dallago, Enrico; Miatton, Daniele; Venchi, Giuseppe; Bottarel, Valeria; Frattini, Giovanni; Ricotti, Giulio; Schipani, Monica

    2010-01-01

    International audience Piezoelectric Energy Scavenging Systems (PESS) are used to convert the energy of mechanical vibrations into electrical energy exploiting the piezoelectric effect. Their output is a voltage which strongly varies in time; to obtain a suitable supply source an AC-DC conversion of the output voltage of these transducers is needed. Since the output power level of the energy transducer can be very low, the conversion should be as efficient as possible. The paper describes ...

  1. DC and AC Josephson Effect in a Superconductor-Luttinger Liquid-Superconductor System

    Fazio, Rosario; Hekking, F. W. J.; Odintsov, A.A.; RevTex, 11 pages; figures, 9

    1995-01-01

    We calculate both the DC and the AC Josephson current through a one-dimensional system of interacting electrons, connected to two superconductors by tunnel junctions. We treat the (repulsive) Coulomb interaction in the framework of the one-channel, spin-$1/2$ Luttinger model. The Josephson current is obtained for two geometries of experimental relevance: a quantum wire and a ring. At zero temperature, the critical current is found to decay algebraically with increasing distance $d$ between th...

  2. MODES OF OPERATION OF THE SYSTEM OF TRACTION POWER AC USING REACTIVE POWER COMPENSATION DEVICES

    Domanskyi, I. V.

    2015-01-01

    The paper presents a systematic analysis of existing methods of reactive power compensation. The study of operating modes of the systems external and traction power supply is carried out. The methodology for selecting promising compensation schemes and energy-saving in the traction networks AC electrified railway lines is offered. The comparative evaluation of prospective controlled compensation devices shows that use of seamlessly adjustable devices with unregulated condensing the battery an...

  3. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network which is dominated by multiple current- and voltage- controlled inverters with LCL- and LC-filters. A method of deriving the impedance ratios for different inverters is proposed by means of the nodal a...

  4. Very low noise AC/DC power supply systems for large detector arrays

    Arnaboldi, C.; Baù, A.; Carniti, P.; Cassina, L.; Giachero, A.; Gotti, C.; Maino, M.; Passerini, A.; Pessina, G.

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μVRMS (CUORE setup) and 90 μVRMS (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled).

  5. Data Acquisition and Transmission System for Building Energy Consumption Monitoring

    Liang Zhao

    2013-01-01

    Full Text Available Building energy consumption monitoring and management system have been developed widely in China in order to gain the real-time data of energy consumption in buildings for analyzing it in the next state work. This paper describes a low-cost and small-sized collector based on the STM32 microcontroller, which can be placed in a building easily to implement the work of data acquisition, storage, and transmission. The collector gathers the electricity, water, heat, and energy consumption data through the RS485 field bus and stores the data into an SD card with mass storage, finally, using Internet to finish the communication and transmission to data server through TCP protocol. The collector has been used in application for two years, and the results show that the system is reliable and stable.

  6. Adaptive Image Transmission Scheme over Wavelet-Based OFDM System

    GAOXinying; YUANDongfeng; ZHANGHaixia

    2005-01-01

    In this paper an adaptive image transmission scheme is proposed over Wavelet-based OFDM (WOFDM) system with Unequal error protection (UEP) by the design of non-uniform signal constellation in MLC. Two different data division schemes: byte-based and bitbased, are analyzed and compared. Different bits are protected unequally according to their different contribution to the image quality in bit-based data division scheme, which causes UEP combined with this scheme more powerful than that with byte-based scheme. Simulation results demonstrate that image transmission by UEP with bit-based data division scheme presents much higher PSNR values and surprisingly better image quality. Furthermore, by considering the tradeoff of complexity and BER performance, Haar wavelet with the shortest compactly supported filter length is the most suitable one among orthogonal Daubechies wavelet series in our proposed system.

  7. Suggested Methods for Preventing Core Saturation Instability in HVDC Transmission Systems

    Norheim, Ian

    2002-07-01

    In this thesis a study of the HVDC related phenomenon core saturation instability and methods to prevent this phenomenon is performed. It is reason to believe that this phenomenon caused disconnection of the Skagerrak HVDC link 10 August 1993. Internationally, core saturation instability has been reported at several HVDC schemes and thorough complex studies of the phenomenon has been performed. This thesis gives a detailed description of the phenomenon and suggest some interesting methods to prevent the development of it. Core saturation instability and its consequences can be described in a simplified way as follows: It is now assumed that a fundamental harmonic component is present in the DC side current. Due to the coupling between the AC side and the DC side of the HVDC converter, a subsequent second harmonic positive-sequence current and DC currents will be generated on the AC side. The DC currents will cause saturation in the converter transformers. This will cause the magnetizing current to also have a second harmonic positive-sequence component. If a high second harmonic impedance is seen from the commutation bus, a high positive-sequence second harmonic component will be present in the commutation voltages. This will result in a relatively high fundamental frequency component in the DC side voltage. If the fundamental frequency impedance at the DC side is relatively low the fundamental component in the DC side current may become larger than it originally was. In addition the HVDC control system may contribute to the fundamental frequency component in the DC side voltage, and in this way cause a system even more sensitive to core saturation instability. The large magnetizing currents that eventually will flow on the AC side cause large zero-sequence currents in the neutral conductors of the AC transmission lines connected to the HVDC link. This may result in disconnection of the lines. Alternatively, the harmonics in the large magnetizing currents may cause

  8. Elimination of SF6 From Transmission System Equipment

    Cai, Xiaolei

    2013-01-01

    Sulphur hexafluoride gas is the dominant insulation and interruption material in high voltage gas insulated substation. Its usage remains a concern of transmission system operators owing to the global warming potential of the gas. The work carried out in this thesis aims to find the environment-friendly materials that can replace SF6. These candidates are required to have a strong dielectric strength for high voltage busbar insulation and well arc extinguishing capability necessary for high v...

  9. A GIS-based Power Transmission Management Information System

    2010-01-01

    <正>Based on analyzing the shortcomings of electric power enterprise in traditional operation pattern,this paper combines components GIS with the application of management information system,and uses the structure which unifies three layers C/S and B/S.Also,proposed using the GPS intellectualization patrol.This may be useful to guarantees the transmission line’s operation to be safe and stable.

  10. The Diagnostic System of A – 604 Automatic Transmission

    Czaban Jaroslaw; Szpica Dariusz

    2014-01-01

    Automatic gearbox gains increasing popularity in Europe. Little interest in diagnosis of such type of transmission in Poland results from the fact of small share in the whole market of operated cars, so there is a lack of availability of special diagnostic devices. These factors cause issues of expensive repairs, often involving a replacement of subassembly to new or aftermarket one. To a small extent some prophylactic diagnostic tests are conducted, which can eliminate future gearbox system ...

  11. Efficient Dynamic Compressor Optimization in Natural Gas Transmission Systems

    Mak, Terrence W. K.; Van Hentenryck, Pascal; Zlotnik, Anatoly; Hijazi, Hassan; Bent, Russell

    2015-01-01

    The growing reliance of electric power systems on gas-fired generation to balance intermittent sources of renewable energy has increased the variation and volume of flows through natural gas transmission pipelines. Adapting pipeline operations to maintain efficiency and security under these new conditions requires optimization methods that account for transients and that can quickly compute solutions in reaction to generator re-dispatch. This paper presents an efficient scheme to minimize com...

  12. Data Acquisition and Transmission System for Building Energy Consumption Monitoring

    Liang Zhao; Jili Zhang; Ruobing Liang

    2013-01-01

    Building energy consumption monitoring and management system have been developed widely in China in order to gain the real-time data of energy consumption in buildings for analyzing it in the next state work. This paper describes a low-cost and small-sized collector based on the STM32 microcontroller, which can be placed in a building easily to implement the work of data acquisition, storage, and transmission. The collector gathers the electricity, water, heat, and energy consumption data thr...

  13. Artificial Intelligence SVC Based Control of Two Machine Transmission System

    Reza Bayat

    2013-07-01

    Full Text Available The main target in this paper is to present, design fuzzy logic controller (FLC applied to static var compensator (SVC on two machine transmission system to improve transient stability and rapid damping oscillations of synchronous generators, when power generators sudden changes occur.stability that also played important role in power systems. static var compensator with fuzzy logic controller (SVCFLC is a new control strategy can help improve transient stability.The effect of three phase fault causes instability on power system. By and large, it is very difficult to control machine speeds ,rotor angle and voltage during three-phase fault.SVCFLC is a voltage stablizer using three static var compensator which are controlled by SVC with fuzzy logic controller(FLC.The FLC is an effective device for transient stability of two-mashine transmission system. The nonlinear model dynamic formulation problem in unstable system can be solved by using artificial intelligence theorem. Fuzzy logic theory is used to improve the system stability . simulation results of three-phase fault in power system show that SVCFLC caused to increase the stability and damp out the oscillation of machine, compared with effective of SVC in the presence of power system stabilizer(PSS.

  14. Control and Simulation of Continuously Variable Transmission for Electric Transmission System

    张豫南; 葛蕴珊; 马晓军; 臧克茂

    2004-01-01

    According to the study of electric transmission, the concept of the fore and the aft power chain is presented. The control method of continuously variable transmission is established in the aft chain of electric transmission based on brushless DC motor. A fuzzy controller is designed with continuous fuzzy variables and the simulation module of the aft power chain is proved by test. The fuzzy controller controls the process of continuously variable transmission steadily and the acceleration of vehicle is quick according to simulation results. The elementary performance exhibited in the simulation is a foundation for the further study of the electric transmission track vehicle.

  15. A novel fiber audio transmission system for secure communication

    SU Ke; JIA Bo

    2005-01-01

    A new,simple and efficient fiber audio transmission method for the long distance secure communication is presented, which performs signal modulation by the strain-optic effects and signal demodulation by the all-fiber interferometer. The interferometer is a truly path-matched device, which eliminates much of the undesirable noise by combining the reference and the sensing arms within the same optical fiber. The sinusoidal signals adopted in the experiment are in a frequency range of 300 HZ-3 400 HZ and of the multi-frequency, and the system shows good capabilities, robust security and maintenance of audio integrity. The device may be applicable in the field of point to point secure communication of 40 kilometer long transmission range.

  16. An Adaptive Coordinated Control for an Offshore Wind Farm Connected VSC Based Multi-Terminal DC Transmission System

    Kumar, M. Ajay; Srikanth, N. V.

    2014-11-01

    The voltage source converter (VSC) based multiterminal high voltage direct current (MTDC) transmission system is an interesting technical option to integrate offshore wind farms with the onshore grid due to its unique performance characteristics and reduced power loss via extruded DC cables. In order to enhance the reliability and stability of the MTDC system, an adaptive neuro fuzzy inference system (ANFIS) based coordinated control design has been addressed in this paper. A four terminal VSC-MTDC system which consists of an offshore wind farm and oil platform is implemented in MATLAB/ SimPowerSystems software. The proposed model is tested under different fault scenarios along with the converter outage and simulation results show that the novel coordinated control design has great dynamic stabilities and also the VSC-MTDC system can supply AC voltage of good quality to offshore loads during the disturbances.

  17. EHV AC undergrounding electrical power performance and planning

    Benato, Roberto

    2010-01-01

    EHV AC Undergrounding Electrical Power discusses methods of analysis for cable performance and for the behaviour of cable, mixed and overhead lines. The authors discuss the undergrounding of electrical power and develop procedures based on the standard equations of transmission lines. They also provide technical and economical comparisons of a variety of cables and analysis methods, in order to examine the performance of AC power transmission systems. A range of topics are covered, including: energization and de-energization phenomena of transmission lines; power quality; and cable safety cons

  18. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  19. Power and signal transmission for mobile teleoperated systems

    Appropriate means must be furnished for supplying power and for sending controlling commands to mobile teleoperated systems. Because a sizable number of possibilities are available for such applications, methods used in designing both the power and communications systems built into mobile vehicles that serve in radiological emergencies must be carefully selected. This paper describes a number of umbilical, on-board, and wireless systems used in tranmitting power that are available for mobile teleoperator services. The pros and cons of selecting appropriate methods from a list of possible communication systems (wired, fiber optic, and radio frequency) are also examined. Moreover, hybrid systems combining wireless power transmissions with command-information signals are also possible

  20. Fuzzy gain auto-tuning implementation for ac speed servo and mechanical motion load system

    In this paper, in order to suppress the mechanical resonance and anti- resonance in the DC brushless motor-based AC speed servo system with two-mass mechanical motion load, the load speed observer with load disturbance estimating function, which is suitable for the load speed feedback compensation, is proposed. The auto-tuning control implementation based on fuzzy reasoning with the observer- based load speed feedback compensation is compared with conventional PI compensation scheme. The experimental results prove considerable reduction in mechanical vibration and show improved response characteristics of mechanical motion load system. (author)

  1. Spin superconductivity and ac-Josephson effect in Graphene system under strong magnetic field

    Liu, Haiwen; Jiang, Hua; Sun, Qing-Feng; Xie, X. C.; Collaborative Innovation Center of Quantum Matter, Beijing, China Collaboration

    We study the spin superconductivity in Graphene system under strong magnetic field. From the microscopically Gor'kov method combined with the Aharonov-Casher effect, we derive the effective Landau-Ginzburg free energy and analyze the time evolution of order parameter, which is confirmed to be the off-diagonal long range order. Meanwhile, we compare the ground state of spin superconductivity to the canted-antiferromagnetic state, and demonstrate the equivalence between these two states. Moreover, we give out the pseudo-field flux quantization condition of spin supercurrent, and propose an experimental measurable ac-Josephson effect of spin superconductivity in this system.

  2. Comparison of the Accuracy and Speed of Transient Mobile A/C System Simulation Models: Preprint

    Kiss, T.; Lustbader, J.

    2014-03-01

    The operation of air conditioning (A/C) systems is a significant contributor to the total amount of fuel used by light- and heavy-duty vehicles. Therefore, continued improvement of the efficiency of these mobile A/C systems is important. Numerical simulation has been used to reduce the system development time and to improve the electronic controls, but numerical models that include highly detailed physics run slower than desired for carrying out vehicle-focused drive cycle-based system optimization. Therefore, faster models are needed even if some accuracy is sacrificed. In this study, a validated model with highly detailed physics, the 'Fully-Detailed' model, and two models with different levels of simplification, the 'Quasi-Transient' and the 'Mapped- Component' models, are compared. The Quasi-Transient model applies some simplifications compared to the Fully-Detailed model to allow faster model execution speeds. The Mapped-Component model is similar to the Quasi-Transient model except instead of detailed flow and heat transfer calculations in the heat exchangers, it uses lookup tables created with the Quasi-Transient model. All three models are set up to represent the same physical A/C system and the same electronic controls. Speed and results of the three model versions are compared for steady state and transient operation. Steady state simulated data are also compared to measured data. The results show that the Quasi-Transient and Mapped-Component models ran much faster than the Fully-Detailed model, on the order of 10- and 100-fold, respectively. They also adequately approach the results of the Fully-Detailed model for steady-state operation, and for drive cycle-based efficiency predictions

  3. Shot noise in nano-electronic systems under the perturbation of ac fields

    ZHAO Hong-kang

    2007-01-01

    Current noise exists in circuits and electronic devices generally, and it exhibits specific features as the system reaches nanometer size. The noise in the nano-system where external ac fields are applied plays an important role, since the properties of the fields and the nano-system together govern the resulting noise. In this paper, we present the derivation of shot noise by employing the nonequilibrium Green's function technique. The more general formulas for the current correlation and noise spectral density are given. The system is composed of a central nanosystem coupled to electrodes, and the obtained noise formulas are related to the Green's functions of detailed central regime and the terminals. As an example, we have performed the numerical calculation on a system with a toroidal carbon nanotube coupled to normal metal leads. The noise and Fano factor show intimate relation with the structure of the system and ac fields. The Aharonov-Bohm-like behaviors on the shot noise spectral density and Fano factor are observed to exhibit oscillation structures with period of quantum flux.

  4. Adaptive transmission schemes for MISO spectrum sharing systems

    Bouida, Zied

    2013-06-01

    We propose three adaptive transmission techniques aiming to maximize the capacity of a multiple-input-single-output (MISO) secondary system under the scenario of an underlay cognitive radio network. In the first scheme, namely the best antenna selection (BAS) scheme, the antenna maximizing the capacity of the secondary link is used for transmission. We then propose an orthogonal space time bloc code (OSTBC) transmission scheme using the Alamouti scheme with transmit antenna selection (TAS), namely the TAS/STBC scheme. The performance improvement offered by this scheme comes at the expense of an increased complexity and delay when compared to the BAS scheme. As a compromise between these schemes, we propose a hybrid scheme using BAS when only one antenna verifies the interference condition and TAS/STBC when two or more antennas are illegible for communication. We first derive closed-form expressions of the statistics of the received signal-to-interference-and-noise ratio (SINR) at the secondary receiver (SR). These results are then used to analyze the performance of the proposed techniques in terms of the average spectral efficiency, the average number of transmit antennas, and the average bit error rate (BER). This performance is then illustrated via selected numerical examples. © 2013 IEEE.

  5. Evaluating parasite densities and estimation of parameters in transmission systems

    Heinzmann D.

    2008-09-01

    Full Text Available Mathematical modelling of parasite transmission systems can provide useful information about host parasite interactions and biology and parasite population dynamics. In addition good predictive models may assist in designing control programmes to reduce the burden of human and animal disease. Model building is only the first part of the process. These models then need to be confronted with data to obtain parameter estimates and the accuracy of these estimates has to be evaluated. Estimation of parasite densities is central to this. Parasite density estimates can include the proportion of hosts infected with parasites (prevalence or estimates of the parasite biomass within the host population (abundance or intensity estimates. Parasite density estimation is often complicated by highly aggregated distributions of parasites within the hosts. This causes additional challenges when calculating transmission parameters. Using Echinococcus spp. as a model organism, this manuscript gives a brief overview of the types of descriptors of parasite densities, how to estimate them and on the use of these estimates in a transmission model.

  6. Soft Computing Technique Based Enhancement of Transmission System Lodability Incorporating Facts

    T. Vara Prasad,

    2014-07-01

    Full Text Available Due to the growth of electricity demands and transactions in power markets, existing power networks need to be enhanced in order to increase their loadability. The problem of determining the best locations for network reinforcement can be formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP. The complexity of the problem makes extensive simulations necessary and the computational requirement is high. This paper compares the effectiveness of Evolutionary Programming (EP and an ordinal optimization (OO technique is proposed in this paper to solve the MDCP involving two types of flexible ac transmission systems (FACTS devices, namely static var compensator (SVC and thyristor controlled series compensator (TCSC, for system loadability enhancement. In this approach, crude models are proposed to cope with the complexity of the problem and speed up the simulations with high alignment confidence. The test and Validation of the proposed algorithm are conducted on IEEE 14–bus system and 22-bus Indian system.Simulation results shows that the proposed models permit the use of OO-based approach for finding good enough solutions with less computational efforts.

  7. Structural vulnerability in transmission systems: Cases of Colombia and Spain

    Highlights: • Vulnerability analysis of transmission electric systems in Colombia and Spain. • Based on scale-free graph statistic indexes. • Evaluating both current conditions and expansion plans of infrastructures. • Comparison of random error and deliberate attack tolerance evaluation. - Abstract: In this paper the authors apply methodological strategies for the structural vulnerability assessment in high voltage power networks based upon the combination of power flow models and scale-free graph statistic indexes. Thus, it is possible to study risk scenarios based on events that may trigger cascading failures within a power system. The usefulness of graph theory techniques has been validated on previous works of the authors, and may be applied in analysis of the vulnerability of different power electric networks. A case study for vulnerability analysis is carried out through methodologies that allow comparison on random error and deliberate attack tolerance evaluation in transmission electric systems from countries like Colombia and Spain. Such vulnerability assessment methodology takes into account the current conditions of the power networks (base case), as well as the impact of expansion plans into infrastructures as defined by their governments. Consequently, the authors show the advantage on the use of graph theory based techniques for vulnerability analysis of electrical power systems

  8. The transmission link of CAPS navigation and communication system

    CUI JunXia; SHI HuLi; CHEN JiBin; PEI Jun

    2009-01-01

    The Chinese Area Positioning System (CAPS) is based on communication satellites with integrated oapability,whioh is different from the Global Positioning System (GPS),the International Maritime Satellite Organization (Inmarsat) and so on.CAPS works at G-band,and its navigation information ie not directly generated from the satellite,but from the master control station on the ground and transmitted to users via the satellite.The slightly inclined geostationary-satellite orbit (SIGSO) satellites are adopted in CAPS.All of these increase the difficulty in the design of the system and terminals.In this paper,the authors study the CAPS oonfiguration parameters of the navigation master control station,information transmission capability,and the selection of the antenna aperture of the communication oenter station,as well as the impact of satellite parameters on the whole communication system from the perspective of the transmission link budget.The conclusion of availability of the GAPS navigation system is achieved.The results show that the GAPS inbound communication system forms a new low-data-rate satellite communicaUon system,which can accommodate mass communication termihale with the transmission rate of no more than 1 kbps for every terminal.The communication center station should be configured with a large-aperture antenna (about 10--15 m); spread spectrum communication technology should be used with the spreading gain as high as about 40 dB; reduction of the satellite transponder gain attenuation is beneficial to improving the signal-to-noise ratio of the system,with the attenuation value of 0 or 2 dB as the best choice.The fact that the GAPS navigation system has been checked and aooepted by the experts and the operation is stable till now larifies the rationality of the analysis results.The fact that a variety of experiments and applications of the satellite communication system designed according to the findings in this paper have been successfully carried out

  9. Peak Power Reduction in OFDM Systems for Multicarrier Transmission

    Sabhyata Uppal

    2013-05-01

    Full Text Available The transmit signals in an OFDM system can have high peak values in the time domain since many subcarrier components are added via an IFFT operation. Therefore, OFDM systems are known to have a high PAPR (Peak-to-Average Power Ratio, compared with single-carrier systems. In fact, the high PAPR is one of the most detrimental aspects in the OFDM system, as it decreases the SQNR (Signal-to-Quantization Noise Ratio of ADC (Analog-to-Digital Converter and DAC (Digital-to-Analog Converter while degrading the efficiency of the power amplifier in the transmitter. This study describes some of the important PAPR reduction techniques for multicarrier transmission including amplitude clipping and filtering, coding and partial transmit.

  10. A flexible computerized system for environmental data acquisition and transmission

    Zappalà, G.

    2009-04-01

    In recent years increasing importance has been addressed to the knowledge of the marine environment, either to help detecting and understanding global climate change phenomena, or to protect and preserve those coastal areas, where multiple interests converge (linked to the tourism, recreational or productive activities…) and which suffer greater impact from anthropogenic activities; this has in turn stimulated the start of research programs devoted to the monitoring and surveillance of these particular zones, coupling the needs for knowledge, sustainable development and exploitation of natural resources. There is an increasing need to have data available in real time or near real time in order to intervene in emergency situations. Cabled or wireless data transmission can be used. The first allows the transmission of a higher amount of data only in coastal sites, while the second gives a bigger flexibility in terms of application to different environments; more, using mobile phone services (either terrestrial or satellite), it is possible to allocate the data centre in the most convenient place, without any need of proximity to the sea. Traditional oceanographic techniques, based on ship surveys, hardly fit the needs of operational oceanography, because of their high cost and fragmentary nature, both in spatial and temporal domains. To obtain a good synopticity, it is necessary to complement traditional ship observations with measurements from fixed stations (buoys moored in sites chosen to be representative of wider areas, or to constitute a sentinel against the arrival of pollutants), satellite observations, use of ships of opportunity and of newly developed instruments, like the gliders, or towed sliding devices, like the SAVE. Modern instruments rely on an electronic heart; an integrated hardware-software system developed in Messina is here presented, used in various versions to control data acquisition and transmission on buoys or on ship

  11. Optimized list-mode acquisition and data processing procedures for ACS2 based PET systems

    PET systems using the acquisition control system version 2 (ACS2), e.g. the ECAT Exact HR PET scanner series, offer a rather restricted list-mode functionality. For instance, typical transfers of acquisition data consume a considerable amount of time. This represents a severe obstacle to the utilization of potential advantages of list-mode acquisition. In our study, we have developed hardware and software solutions which do not only allow for the integration of list-mode into routine procedures, but also improve the overall runtime stability of the system. We show that our methods are able to speed up the transfer of the acquired data to the image reconstruction and processing workstations by a factor of up to 140. We discuss how this improvement allows for the integration of list-mode-based post-processing methods such as an event-driven movement correction into the data processing environment, and how list-mode is able to improve the overall flexibility of PET investigations in general. Furthermore, we show that our methods are also attractive for conventional histogram-mode acquisition, due to the improved stability of the ACS2 system. (orig.)

  12. Efficient harvesting of wet blue-green microalgal biomass by two-aminoclay [AC]-mixture systems.

    Ji, Hye-Min; Lee, Hyun Uk; Kim, Eui Jin; Seo, Soonjoo; Kim, Bohwa; Lee, Go-Woon; Oh, You-Kwan; Kim, Jun Yeong; Huh, Yun Suk; Song, Hyun A; Lee, Young-Chul

    2016-07-01

    Blue-green microalgal blooms have been caused concerns about environmental problems and human-health dangers. For removal of such cyanobacteria, many mechanical and chemical treatments have been trialled. Among various technologies, the flocculation-based harvesting (precipitation) method can be an alternative if the problem of the low yield of recovered biomass at low concentrations of cyanobacteria is solved. In the present study, it was utilized mixtures of magnesium aminoclay [MgAC] and cerium aminoclay [CeAC] with different particle sizes to harvest cyanobacteria feedstocks with ∼100% efficiency within 1h by ten-fold lower loading of ACs compared with single treatments of [MgAC] or [CeAC]. This success was owed to the compact networks of the different-sized-ACs mixture for efficient bridging between microalgal cells. In order to determine the usage potential of biomass harvested with AC, the mass was heat treated under the reduction condition. This system is expected to be profitably utilizable in adsorbents and catalysts. PMID:27023387

  13. ARQ schemes for data transmission in mobile radio systems

    Comroe, R. A.; Costello, D. J., Jr.

    1984-01-01

    The problem of providing data communications over a land mobile radio channel is considered, taking into account error detection combined with retransmission on request as a means of obtaining reliability in digital data transmission. The considered systems are referred to as automatic RQ (repeat-request) or ARQ. It is pointed out that the distinguishing features of a land mobile radio (LMR) system, as far as the ARQ protocol is concerned, are a frequency or pair of frequencies shared by a large population of half-duplex users which cannot transmit and receive simultaneously. A description is presented of those variations of ARQ which are adaptable to an LMR system. A new channel model for a fading LMR channel is developed, and several ARQ protocols and some new protocol combinations are described. The relationships are developed for a description of the various protocols in terms of channel failure probabilities. Undetected error probabilities are developed and compared.

  14. Passive AC network supplying the integration of CCC-HVDC and VSC-HVDC systems

    BIDADFAR, Ali; Abedi, Mehrdad; KARRARI, Mehdi

    2014-01-01

    The integration of a capacitor-commutated converter (CCC) high-voltage direct current (HVDC) (CCC-HVDC) and voltage source converter (VSC) HVDC (VSC-HVDC) is proposed in this paper to supply entirely passive AC networks. The key point of this integration is the flat characteristic of the DC voltage of the CCC-HVDC, which provides the condition for the VSC to connect to the CCC DC link via a current regulator. The advantages of the proposed combined infeeding system are the requirement o...

  15. Coordinated Secondary Control for Balanced Discharge Rate of Energy Storage System in Islanded AC Microgrids

    Guan, Yajuan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2016-01-01

    A coordinated secondary control approach based on an autonomous current-sharing control strategy for balancing the discharge rates of energy storage systems (ESSs) in islanded AC microgrids is proposed in this paper. The coordinated secondary controller can regulate the power outputs of distributed...... generation (DG) units according to their states-of-charge (SoCs) and ESS capacities by adjusting the virtual resistances of the paralleled voltage-controlled inverters. Compared with existing controllers, the proposed control strategy not only effectively prevents operation failure caused by overcurrent...

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

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

    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...

  17. Marine High Voltage Power Conditioning and Transmission System with Integrated Storage DE-EE0003640 Final Report

    Frank Hoffmann, PhD; Aspinall, Rik

    2012-12-10

    Design, Development, and test of the three-port power converter for marine hydrokinetic power transmission. Converter provides ports for AC/DC conversion of hydrokinetic power, battery storage, and a low voltage to high voltage DC port for HVDC transmission to shore. The report covers the design, development, implementation, and testing of a prototype built by PPS.

  18. Study on Reclosure Sequence of AC Transmission Lines Near Converter Stations%换流站近端交流输电线路重合时序问题研究

    束洪春; 孙士云; 刘可真; 戴月涛

    2012-01-01

    DC systems are sensitive to AC systems' disturbances in the AC/DC power systems. The transmission of DC power may be interrupted by the disturbances of rectifier stations or inverter stations. Through researches it was discovered that the reclosure sequence of transmission lines near converter stations has effects on the operation parameters such as voltage, power, and turn-off angle of DC systems. Its mechanism was discussed in an AC/DC power system. Firstly, the DC system was equated using the switch function method, and then the converter bus voltage of AC side was solved after one side of the line reclosed when a single-phase fault occurred on any point of the line. The critical fault distance affecting reelosure sequence was obtained by comparing the converter bus voltages of AC side under two different reclosure sequences. Furthermore, when the communication transformers respectively adopted Y0/Y and Y0/D connections, the relationship between the commutation voltages of network side and valve side was analyzed, and also the relationship between DC voltage, power, turn-off angle and the converter bus voltage of AC side were researched. On this basis, the conclusion was obtained: when a fault occurs on the lines near converter stations, higher DC voltage and power can be maintained and the probability to cause communication failure can be reduced by reclosing to the side of the line having higher converter bus voltage, and thus the impacts brought by reclosing to a permanent fault can be decreased. Theconclusion was verified to be correct by large digital test in the PSCAD.%交直流电力系统中直流系统对交流系统的扰动较为敏感,整流站或逆变站的扰动都可能造成直流功率的传输中断。经研究发现,换流站近端交流线路重合闸投入时序对直流系统的电压、功率、关断角等运行参量有较大影响。在交直流电力系统中探讨其机理,首先采用开关函数法对直流系统进行

  19. A flexible computerized system for environmental data acquisition and transmission

    Zappalà, G.

    2009-04-01

    In recent years increasing importance has been addressed to the knowledge of the marine environment, either to help detecting and understanding global climate change phenomena, or to protect and preserve those coastal areas, where multiple interests converge (linked to the tourism, recreational or productive activities…) and which suffer greater impact from anthropogenic activities; this has in turn stimulated the start of research programs devoted to the monitoring and surveillance of these particular zones, coupling the needs for knowledge, sustainable development and exploitation of natural resources. There is an increasing need to have data available in real time or near real time in order to intervene in emergency situations. Cabled or wireless data transmission can be used. The first allows the transmission of a higher amount of data only in coastal sites, while the second gives a bigger flexibility in terms of application to different environments; more, using mobile phone services (either terrestrial or satellite), it is possible to allocate the data centre in the most convenient place, without any need of proximity to the sea. Traditional oceanographic techniques, based on ship surveys, hardly fit the needs of operational oceanography, because of their high cost and fragmentary nature, both in spatial and temporal domains. To obtain a good synopticity, it is necessary to complement traditional ship observations with measurements from fixed stations (buoys moored in sites chosen to be representative of wider areas, or to constitute a sentinel against the arrival of pollutants), satellite observations, use of ships of opportunity and of newly developed instruments, like the gliders, or towed sliding devices, like the SAVE. Modern instruments rely on an electronic heart; an integrated hardware-software system developed in Messina is here presented, used in various versions to control data acquisition and transmission on buoys or on ship

  20. Nonlinear Vibroimpact Characteristics of a Planetary Gear Transmission System

    Jianxing Zhou

    2016-01-01

    Full Text Available In order to research the vibroimpact characteristics of a planetary gear transmission system under high speed and lightly loaded conditions, a new modeling method is proposed. In the modeling process, linear spring was used to simulate gear mesh elasticity under heavy load cases, and Hertz contact theory was used to calculate the contact force of gear pair under light load cases. Then, effects of the working conditions on the system vibroimpact characteristics are analyzed. The results show that, with input speed growing, the mesh force produced obvious fluctuations on the resonance frequencies of the sun gear and carrier torsion vibration, ring gear’s transverse vibration under the heavy load. Under light load condition, the collision vibration occurs in the gear pair; the changing trend of the contact force shows strongly nonlinear characteristics. The time of mesh-apart in gears pair decreases gradually as the load is increased; until it reaches collision vibration threshold value, the gear pair is no longer mesh-apart. With increasing of the input speed, the time of mesh-apart is decreased gradually; the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline for planetary gear transmission low-noise design.

  1. Governance of competitive transmission investment in weak institutional systems

    Abdala, Manuel A. [LECG, LLC, 1725 Eye St NW - Suite 800, Washington, DC 20006 (United States)

    2008-07-15

    Despite progress in economic analysis in recent years, transmission investment governance still poses policy design challenges in competitive electricity systems. The degree of regulatory intervention in allocating investment costs is a central issue. Scholars tend to agree that centralized solutions are almost inevitable, mainly due to free riding and coordination problems. In systems with weak institutional endowments and pressures of distributive politics, however, there is an increased likelihood of regulators acting opportunistically or imposing arbitrary changes to the cost allocation rules, which makes centralized solutions less desirable. We provide some examples from Argentina, El Salvador and Peru and suggest that a two-tier governance scheme composed of a self-governing Forum of transmission stakeholders, with regulation as a subsidiary measure, may be a more adequate design to restraint undue government interference. The expected outcome is twofold: a better match with users' preferences and a restraint to government opportunism and arbitrariness. Measuring the robustness of this scheme in minimizing the risks for either too much or too little investment will certainly require further research. (author)

  2. Voltage Stability Bifurcation Analysis for AC/DC Systems with VSC-HVDC

    Yanfang Wei

    2013-01-01

    Full Text Available A voltage stability bifurcation analysis approach for modeling AC/DC systems with VSC-HVDC is presented. The steady power model and control modes of VSC-HVDC are briefly presented firstly. Based on the steady model of VSC-HVDC, a new improved sequential iterative power flow algorithm is proposed. Then, by use of continuation power flow algorithm with the new sequential method, the voltage stability bifurcation of the system is discussed. The trace of the P-V curves and the computation of the saddle node bifurcation point of the system can be obtained. At last, the modified IEEE test systems are adopted to illustrate the effectiveness of the proposed method.

  3. Shift Control System of Heavy-duty Vehicle Automatic Transmission

    Yan Zhang

    2013-12-01

    Full Text Available Heavy-duty vehicle hydrodynamic mechanical automatic transmission shifting operation system was designed, mathematical model of its simplified hydraulic system was established and simulation model of shifting operation system was established with AMESim, the simulation experiment was carried out, then oil pressure curves of each clutch hydraulic cylinder were obtained when giving forward gear or reverse gear signals. The simulation results show that shifting operating system meets the design requirements, and verify the correctness of the model. The shift timing is correct, and there is no power interruption or gear overlap during the shift transition process. Joint oil pressure of designed system is stable, and shifting shock is small. The research results are providing the basis for further study of shifting operation system and a reasonable platform for the studying of shift schedule and quality. The theoretical design method and dynamic simulation experiment will be feasible for the real industrial applications. The research results can be used in design and optimization of hydraulic system

  4. Developing standard transmission system for radiology reporting including key images

    Development of hospital information system and Picture Archiving Communication System is not new in the medical field, and the development of internet and information technology are also universal. In the course of such development, however, it is hard to share medical information without a refined standard format. Especially in the department of radiology, the role of PACS has become very important in interchanging information with other disparate hospital information systems. A specific system needs to be developed that radiological reports are archived into a database efficiently. This includes sharing of medical images. A model is suggested in this study in which an internal system is developed where radiologists store necessary images and transmit them is the standard international clinical format, Clinical Document Architecture, and share the information with hospitals. CDA document generator was made to generate a new file format and separate the existing storage system from the new system. This was to ensure the access to required data in XML documents. The model presented in this study added a process where crucial images in reading are inserted in the CDA radiological report generator. Therefore, this study suggests a storage and transmission model for CDA documents, which is different from the existing DICOM SR. Radiological reports could be better shared, when the application function for inserting images and the analysis of standard clinical terms are completed

  5. SURGNET: An Integrated Surgical Data Transmission System for Telesurgery

    Sriram Natarajan

    2009-01-01

    Full Text Available Remote surgery information requires quick and reliable transmission between the surgeon and the patient site. However, the networks that interconnect the surgeon and patient sites are usually time varying and lossy which can cause packet loss and delay jitter. In this paper we propose SURGNET, a telesurgery system for which we developed the architecture, algorithms and implemented it on a testbed. The algorithms include adaptive packet prediction and buffer time adjustment techniques which reduce the negative effects caused by the lossy and time varying networks. To evaluate the proposed SURGNET system, at the therapist site, we implemented a therapist panel which controls the force feedback device movements and provides image analysis functionality. At the patient site we controlled a virtual reality applet built in Matlab. The varying network conditions were emulated using NISTNet emulator. Our results show that even for severe packet loss and variable delay jitter, the proposed integrated synchronization techniques significantly improve SURGNET performance.

  6. Dynamic security risk assessment and optimization of power transmission system

    2008-01-01

    The paper presents a practical dynamic security region (PDSR) based dynamic security risk assessment and optimization model for power transmission system. The cost of comprehensive security control and the influence of uncertainties of power injections are considered in the model of dynamic security risk assessment. The transient stability constraints and uncertainties of power injections can be considered easily by PDSR in form of hyper-box. A method to define and classify contingency set is presented, and a risk control optimization model is given which takes total dynamic insecurity risk as the objective function for a dominant con-tingency set. An optimal solution of dynamic insecurity risk is obtained by opti-mizing preventive and emergency control cost and contingency set decomposition. The effectiveness of this model has been proved by test results on the New Eng-land 10-genarator 39-bus system.

  7. System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

    Lipo, Thomas A.; Alan, Irfan

    1991-06-01

    Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the

  8. Real-time modeling and controls analysis using the MMS and the IBM advanced control system (ACS)

    The Penn State Nuclear Engineering Department has been used the EPRI sponsored Modular Modeling System (MMS) for research and education since 1985. The new capability presented in this paper is the adaptation of the MMS modeling procedure to produce a real-time interactive simulator. The technique additionally uses existing features of the Advanced Continuous Simulation Language (ACSL) and a commercially available control system for industrial applications, the IBM Advanced Control System (ACS). In the university environment, the IBM ACS mainframe software is used to effect the real-time interactive simulator capability. Successful demonstration of the basic mechanics for converting an existing batch mode MMS simulation to a real-time simulator using the ACS has been achieved for the MMS Deaerator example model. Future near-term work is expected to produce a real-time simulation of a primary loop of a Nuclear Steam Supply System that is used in an undergraduate Systems Interaction Course at Penn State

  9. Toroidal Continuously Variable Transmission Systems: Terminology and Present Studies

    Ahmet YILDIZ

    2014-04-01

    Full Text Available The use of continuously variable transmission systems in many different areas such as aerospace, robotics, machinery and automotive industries as an alternative to conventional speed changers with constant ratio becomes widely.Especially in the automotive industry, these systems have been used increasingly, since they enable that internal combustion engines in vehicles run at optimal speeds, and consequently provide considerable fuel savings and therefore lower emission values and also they provide powerful acceleration and quiet working. CVT systems have several constructive variants such as belted, chained, balled, toroidal etc. In this paper, toroidal CVT systems based on elastohydrodynamic principles are concerned with, and fundamental works of last two decades in this field are reviewed. However, the relevant terminology and dynamics along with the control of these systems are briefly treated for better understanding of the literature mentioned. Attention is drawn to the lack of some significant issues in present research works, and potential future works are pointed out. This paper, to the authors’ knowledge, will be the first review on toroidal CVT systems in Turkish literature

  10. Lowest of AC-DC power output for electrostrictive polymers energy harvesting systems

    Meddad, Mounir; Eddiai, Adil; Hajjaji, Abdelowahed; Guyomar, Daniel; Belkhiat, Saad; Boughaleb, Yahia; Chérif, Aida

    2013-11-01

    Advances in technology led to the development of electronic circuits and sensors with extremely low electricity consumption. At the same time, structural health monitoring, technology and intelligent integrated systems created a need for wireless sensors in hard to reach places in aerospace vehicles and large civil engineering structures. Powering sensors with energy harvesters eliminates the need to replace batteries on a regular basis. Scientists have been forced to search for new power source that are able to harvested energy from their surrounding environment (sunlight, temperature gradients etc.). Electrostrictive polymer belonging to the family of electro-active polymers, offer unique properties for the electromechanical transducer technology has been of particular interest over the last few years in order to replace conventional techniques such as those based on piezoelectric or electromagnetic, these materials are highly attractive for their low-density, with large strain capability that can be as high as two orders of magnitude greater than the striction-limited, rigid and fragile electroactive ceramics. Electrostrictive polymers sensors respond to vibration with an ac output signal, one of the most important objectives of the electronic interface is to realize the required AC-DC conversion. The goal of this paper is to design an active, high efficiency power doubler converter for electrostrictive polymers exclusively uses a fraction of the harvested energy to supply its active devices. The simulation results show that it is possible to obtain a maximum efficiency of the AC-DC converter equal to 80%. Premiliminary experimental measurements were performed and the results obtained are in good agreement with simulations.

  11. dc and ac Josephson effect in a superconductor endash Luttinger-liquid endash superconductor system

    We calculate both the dc and the ac Josephson current through a 1-D system of interacting electrons, connected to two superconductors by tunnel junctions. We treat the (repulsive) Coulomb interaction in the framework of the one-channel, spin-1/2 Luttinger model. The Josephson current is obtained for two geometries of experimental relevance: a quantum wire and a ring. At T=0, the critical current is found to decay algebraically with increasing distance d between the junctions. The decay is characterized by an exponent which depends on the strength of the interaction. At finite temperatures T, lower than the superconducting transition temperature Tc, there is a crossover from algebraic to exponential decay of the critical current as a function of d, at a distance of the order of ℎvF/kBT. Moreover, the dependence of critical current on temperature shows nonmonotonic behavior. If the Luttinger liquid is confined to a ring of circumference L, coupled capacitively to a gate voltage and threaded by a magnetic flux, the Josephson current shows remarkable parity effects under the variation of these parameters. For some values of the gate voltage and applied flux, the ring acts as a π junction. These features are robust against thermal fluctuations up to temperatures on the order of ℎvF/kBL. For the wire geometry, we have also studied the ac-Josephson effect. The amplitude and the phase of the time-dependent Josephson current are affected by electron-electron interactions. Specifically, the amplitude shows pronounced oscillations as a function of the bias voltage due to the difference between the velocities of spin and charge excitations in the Luttinger liquid. Therefore, the ac-Josephson effect can be used as a tool for the observation of spin-charge separation. copyright 1996 The American Physical Society

  12. Insulation measurement and supervision in live AC and DC unearthed systems

    Olszowiec, Piotr

    2014-01-01

    Low voltage unearthed (IT) AC and DC systems are commonly applied for supply of power and control circuits in industry, transportation, medical objects etc. The main reasons for their use are high reliability and numerous advantages offered by isolating them against ground. Insulation level is a decisive factor for networks operational reliability and safety. Insufficient insulation-to-ground resistance can cause various disturbances. Though ground faults in IT systems do not make networks operation impossible, they may cause severe problems with their safe functioning. In this book the most important issues concerning normal operation and ground fault phenomena are described in concise form. Numerous methods of insulation resistance and capacitance measurement in live circuits are presented. Important other procedures of  these parameters determination based on measurement and calculation are explained and reviews of selected insulation resistance measurement devices as well as earth fault locating systems ...

  13. Insulation measurement and supervision in live AC and DC unearthed systems

    Olszowiec, Piotr

    2013-01-01

    Low voltage unearthed (IT) AC and DC systems are commonly applied for supply of power and control circuits in industry, transportation, medical objects etc. The main reasons for their use are high reliability and numerous advantages offered by isolating them against ground. Insulation level is a decisive factor for networks operational reliability and safety. Insufficient insulation-to-ground resistance can cause various disturbances. Though ground faults in IT systems do not make networks operation impossible, they may cause severe problems with their safe functioning. In this book the most important issues concerning normal operation and ground fault phenomena are described in concise form. Numerous methods of insulation resistance and capacitance measurement in live circuits are presented. Important other procedures of  these parameters determination based on measurement and calculation are explained and reviews of selected insulation resistance measurement devices as well as earth fault locating systems ...

  14. Research of novel oscillating wire feeding system using the AC servo motor

    杨世彦; 于志; 刘喆

    2003-01-01

    With the background of the control of additional mechanical force droplet transfer in MIG/MAG welding, regarding the AC servo motor as core, a novel oscillating wire feeding system has been developed with excellent performances of control and dynamic acceleration which is tested. System constitution and operation principle are introduced in this paper. Influences of parameters on dynamic acceleration performance are analyzed and discussed emphatically, such as oscillating frequency, oscillating amplitude and draw-back speed. Experimental result indicates that according to the technique of welding control, the novel wire feeding system responds rapidly to various kinds of control orders of wire feeding and draw-back, and realizes flexible control of welding wire axial movement, including dynamic shifting,oscillating and so on.

  15. Hybrid energy harvesting/transmission system for embedded devices

    Hehr, Adam; Park, Gyuhae; Farinholt, Kevin

    2012-04-01

    In most energy harvesting applications the need for a reliable long-term energy supply is essential in powering embedded sensing and control electronics. The goal of many harvesters is to extract energy from the ambient environment to power hardware; however in some applications there may be conditions in which the harvester's performance cannot meet all of the demands of the embedded electronics. One method for addressing this shortfall is to supplement harvested power through the transmission of wireless energy, a concept that has successfully been demonstrated by the authors in previous studies. In this paper we present our findings on the use of a single electromagnetic coil to harvest kinetic energy in a solenoid configuration, as well as background and directed wireless energy in the 2.4 GHz radio frequency (RF) bands commonly used in WiFi and cellular phone applications. The motivation for this study is to develop a compact energy harvester / receiver that conserves physical volume, while providing multi-modal energy harvesting capabilities. As with most hybrid systems there are performance trade-offs that must be considered when capturing energy from different physical sources. As part of this paper, many of the issues related to power transmission, physical design, and potential applications are addressed for this device.

  16. Transmission media appropriate laser-microwave solar power satellite system

    Schäfer, C. A.; Gray, D.

    2012-10-01

    As a solution to the most critical problems with Solar power Satellite (SPS) development, a system is proposed which uses laser power transmission in space to a receiver high in the atmosphere that relays the power to Earth by either cable or microwave power transmission. It has been shown in the past that such hybrid systems have the advantages of a reduction in the mass of equipment required in geostationary orbit and avoidance of radio frequency interference with other satellites and terrestrial communications systems. The advantage over a purely laser power beam SPS is that atmospheric absorption is avoided and outages due to clouds and precipitation will not occur, allowing for deployment in the equatorial zone and guaranteeing year round operation. This proposal is supported by brief literature surveys and theoretical calculations to estimate crucial parameters in this paper. In relation to this concept, we build on a recently proposed method to collect solar energy by a tethered balloon at high altitude because it enables a low-cost start for bringing the first Watt of power to Earth giving some quick return on investment, which is desperately missing in the traditional SPS concept. To tackle the significant problem of GW-class SPSs of high launch cost per kg mass brought to space, this paper introduces a concept which aims to achieve a superior power over mass ratio compared to traditional satellite designs by the use of thin-film solar cells combined with optical fibres for power delivery. To minimise the aperture sizes and cost of the transmitting and receiving components of the satellite and high altitude receiver, closed-loop laser beam pointing and target tracking is crucial for pointing a laser beam onto a target area that is of similar size to the beam's diameter. A recently developed technique based on optical phase conjugation is introduced and its applicability for maintaining power transmission between the satellite and high altitude receiver is

  17. Research on target information optics communications transmission characteristic and performance in multi-screens testing system

    Li, Hanshan

    2016-04-01

    To enhance the stability and reliability of multi-screens testing system, this paper studies multi-screens target optical information transmission link properties and performance in long-distance, sets up the discrete multi-tone modulation transmission model based on geometric model of laser multi-screens testing system and visible light information communication principle; analyzes the electro-optic and photoelectric conversion function of sender and receiver in target optical information communication system; researches target information transmission performance and transfer function of the generalized visible-light communication channel; found optical information communication transmission link light intensity space distribution model and distribution function; derives the SNR model of information transmission communication system. Through the calculation and experiment analysis, the results show that the transmission error rate increases with the increment of transmission rate in a certain channel modulation depth; when selecting the appropriate transmission rate, the bit error rate reach 0.01.

  18. Antenna and transmission system for high power electron cyclotron heating in a compact helical system

    An electron cyclotron heating (ECH) system for the compact helical system using two types of high power gyrotron as a power source is designed. In order to utilize fully the advantage of the ECH, the antenna system is designed so as to inject the microwave power as an elliptic gaussian beam, which allows well-defined high power local heating. This antenna and associated transmission system from gyrotron are designed with the quasi-optical concept. This design concept and the results of the cold test for the transmission and antenna system are described. The resultant beam parameter of the cold test for the antenna system shows fairly good agreement with the designed value, which indicates the validity of this design concept. The power transmission efficiency of about 90% was estimated from the measured power at both ends. ((orig.))

  19. Field tests of the Liberty-Mead transmission system

    Eilts, L.E.

    1979-08-01

    Summarized are results of the October 1977 field tests of the 383-km(238-mi), 345-kV, series-capacitor-compensated Liberty-Mead transmission line of the Western Area Power Administration. The test series included routine capacitor bypass and insertion tests, line switching tests, and staged-fault tests. Principal results are presented in several figures, tables, and oscillograms. The tests demonstrated that routine capacitor bypass and insertion do not adversely affect the power system; line switching surges are modest, but reclosing, using the existing switchgear, is precluded by trapped charge; high-speed capacitor bypass was achieved but reinsertion proceeded slower than permitted by the specifications; breaker interrupting performance was acceptable; and, excepting some minor problems that were identified, the line relaying schemes generally performed satisfactorily.

  20. Microwave transmission systems for the plasma separation process

    The Plasma Separation Process now employs a 28 GHz cw gyrotron (VGA-8000) for electron cyclotron heating. Frequency increases to 56 GHz in FY 84 and approx. 140 GHz in FY '87 are planned. The tripple miter bend waveguide system in use with the VGA-8000 will be upgraded to provide mode control. The mode output of the tube is being measured; cippled wall converters will transform the tube output (TE01, TE02, TE03) to a single mode. Transmission will proceed through reduced diameter corrugated waveguide bends or bends will be eliminated by use of a horizontally mounted tube. Directional couplers will measure forward power in the dominant mode and multi-mode reflected power

  1. On multiuser switched diversity transmission for spectrum sharing systems

    Qaraqe, Marwa

    2012-01-01

    In this paper, we develop multiuser access schemes for spectrum sharing systems whereby secondary users share the spectrum with primary users. In particular, we devise two schemes for selecting the user among those that satisfy the interference constraints and achieve an acceptable signal-to-noise ratio (SNR) level. The first scheme selects the user with the maximum SNR at the receiver, whereas in the second scheme the users are scanned in a sequential manner until an acceptable user is found. In addition, we consider two power adaptive settings. In the on/off power adaptive setting, the users transmit based on whether the interference constraint is met or not while in the full power adaptive setting, the users vary their transmission power to satisfy the interference constraint. Finally, we present numerical results of our proposed algorithms where we show the trade-off between the average spectral efficiency and average feedback load of both schemes. © 2012 ICST.

  2. Transmission imaging for integrated PET-MR systems

    Bowen, Spencer L.; Fuin, Niccolò; Levine, Michael A.; Catana, Ciprian

    2016-08-01

    Attenuation correction for PET-MR systems continues to be a challenging problem, particularly for body regions outside the head. The simultaneous acquisition of transmission scan based μ-maps and MR images on integrated PET-MR systems may significantly increase the performance of and offer validation for new MR-based μ-map algorithms. For the Biograph mMR (Siemens Healthcare), however, use of conventional transmission schemes is not practical as the patient table and relatively small diameter scanner bore significantly restrict radioactive source motion and limit source placement. We propose a method for emission-free coincidence transmission imaging on the Biograph mMR. The intended application is not for routine subject imaging, but rather to improve and validate MR-based μ-map algorithms; particularly for patient implant and scanner hardware attenuation correction. In this study we optimized source geometry and assessed the method’s performance with Monte Carlo simulations and phantom scans. We utilized a Bayesian reconstruction algorithm, which directly generates μ-map estimates from multiple bed positions, combined with a robust scatter correction method. For simulations with a pelvis phantom a single torus produced peak noise equivalent count rates (34.8 kcps) dramatically larger than a full axial length ring (11.32 kcps) and conventional rotating source configurations. Bias in reconstructed μ-maps for head and pelvis simulations was  ⩽4% for soft tissue and  ⩽11% for bone ROIs. An implementation of the single torus source was filled with 18F-fluorodeoxyglucose and the proposed method quantified for several test cases alone or in comparison with CT-derived μ-maps. A volume average of 0.095 cm‑1 was recorded for an experimental uniform cylinder phantom scan, while a bias of  fixed torus geometry, in combination with translation of the patient table to perform complete tomographic sampling, generated highly quantitative measured

  3. Transmission imaging for integrated PET-MR systems

    Bowen, Spencer L.; Fuin, Niccolò; Levine, Michael A.; Catana, Ciprian

    2016-08-01

    Attenuation correction for PET-MR systems continues to be a challenging problem, particularly for body regions outside the head. The simultaneous acquisition of transmission scan based μ-maps and MR images on integrated PET-MR systems may significantly increase the performance of and offer validation for new MR-based μ-map algorithms. For the Biograph mMR (Siemens Healthcare), however, use of conventional transmission schemes is not practical as the patient table and relatively small diameter scanner bore significantly restrict radioactive source motion and limit source placement. We propose a method for emission-free coincidence transmission imaging on the Biograph mMR. The intended application is not for routine subject imaging, but rather to improve and validate MR-based μ-map algorithms; particularly for patient implant and scanner hardware attenuation correction. In this study we optimized source geometry and assessed the method’s performance with Monte Carlo simulations and phantom scans. We utilized a Bayesian reconstruction algorithm, which directly generates μ-map estimates from multiple bed positions, combined with a robust scatter correction method. For simulations with a pelvis phantom a single torus produced peak noise equivalent count rates (34.8 kcps) dramatically larger than a full axial length ring (11.32 kcps) and conventional rotating source configurations. Bias in reconstructed μ-maps for head and pelvis simulations was  ⩽4% for soft tissue and  ⩽11% for bone ROIs. An implementation of the single torus source was filled with 18F-fluorodeoxyglucose and the proposed method quantified for several test cases alone or in comparison with CT-derived μ-maps. A volume average of 0.095 cm‑1 was recorded for an experimental uniform cylinder phantom scan, while a bias of  range, and differed greatly for highly attenuating materials in the case of the patient table, compared to CT results. Use of a fixed torus geometry, in

  4. Evaluation of reliability of on-site A.C. power systems based on maintenance records

    To the end of ascertain in what extent the evaluation of reliability of emergency diesel generators (D.G.) can be improved by means of a deeper knowledge of their operating history a study has been carried-out on 21 D.G. sets: 4 D.G. of the Caorso nuclear plant (BWR, 870 MWe) and 17 D.G. in service at 6 steam-electric fossil-fuelled plants. The major points of interest resulting from this study are: 1) reliability assessments of A.C. on-site power Systems, made on the basis of outcomes of surveillance tests, may lead to results which overestimate the real performance. 2) the unreliability of a redundant System of stand-by components is determined in large extent by unavailabilities due to scheduled and unscheduled maintenance, latent failures, tests. (authors)

  5. Comparison of Multi-Line Power Flow Control using Unified power flow controller (UPFC and Interline Power Flow Controller (IPFC in Power Transmission Systems

    SUNIL KUMAR JILLEDI

    2011-04-01

    Full Text Available The Unified power flow controller (UPFC and Interline power flow controller (IPFC are two latest generation flexible AC transmission systems (FACTS controller used to control power flows ofmultiple transmission lines. This paper presents a mathematical model of UPFC and IPFC, termed as power injection model (PIM. This model is incorporated in Newton- Raphson (NR power flow algorithmto study the power flow control in transmission lines in which UPFC and IPFC is placed and power flows are compared. A program in MATLAB has been written in order to extend conventional NR algorithmbased on this model. Numerical results are carried out on a standard 2 machine 5 bus system. The results are seen with our incoperation of any FACTS device and it has been compared with incorporation ofUPFC and IPFC are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model.

  6. The sluggs survey: HST/ACS mosaic imaging of the NGC 3115 globular cluster system

    Jennings, Zachary G.; Romanowsky, Aaron J.; Brodie, Jean P.; Arnold, Jacob A. [University of California Observatories, Santa Cruz, CA 95064 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, MI 48824 (United States); Lin, Dacheng; Irwin, Jimmy A.; Wong, Ka-Wah [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Sivakoff, Gregory R., E-mail: zgjennin@ucsc.edu [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

    2014-08-01

    We present Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) g and z photometry and half-light radii R {sub h} measurements of 360 globular cluster (GC) candidates around the nearby S0 galaxy NGC 3115. We also include Subaru/Suprime-Cam g, r, and i photometry of 421 additional candidates. The well-established color bimodality of the GC system is obvious in the HST/ACS photometry. We find evidence for a 'blue tilt' in the blue GC subpopulation, wherein the GCs in the blue subpopulation get redder as luminosity increases, indicative of a mass-metallicity relationship. We find a color gradient in both the red and blue subpopulations, with each group of clusters becoming bluer at larger distances from NGC 3115. The gradient is of similar strength in both subpopulations, but is monotonic and more significant for the blue clusters. On average, the blue clusters have ∼10% larger R {sub h} than the red clusters. This average difference is less than is typically observed for early-type galaxies but does match that measured in the literature for the Sombrero Galaxy (M104), suggesting that morphology and inclination may affect the measured size difference between the red and blue clusters. However, the scatter on the R {sub h} measurements is large. We also identify 31 clusters more extended than typical GCs, which we term ultra-compact dwarf (UCD) candidates. Many of these objects are actually considerably fainter than typical UCDs. While it is likely that a significant number will be background contaminants, six of these UCD candidates are spectroscopically confirmed as NGC 3115 members. To explore the prevalence of low-mass X-ray binaries in the GC system, we match our ACS and Suprime-Cam detections to corresponding Chandra X-ray sources. We identify 45 X-ray-GC matches: 16 among the blue subpopulation and 29 among the red subpopulation. These X-ray/GC coincidence fractions are larger than is typical for most GC systems, probably due to the increased

  7. Component tests for the ITER Ion Cyclotron Transmission Line and Matching System - Status and Plans

    Goulding, R. H.; McCarthy, M. P.; Deibele, C. E.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Campbell, I. H.; Gray, S. L.; Moon, R. L.; Pesavento, P. V.; Sanabria, R. M.; Fredd, E.; Greenough, N.; Kung, C.

    2015-11-01

    New Z0 = 50 Ω gas-cooled component designs for the ITER Ion Cyclotron Heating and Current Drive System have been successfully tested at high RF power levels. They include two types featuring spoke-ring assembly (SRA) inner conductor supports: 20° elbows, and variable length assembly bellows, both achieving RF voltages > 35 kV peak, and currents ~ 760 A peak during quasi-steady state operation. The SRA utilizes mechanically preloaded fused quartz spokes, increasing lateral load handling capability. Components with SRA supports have been seismically tested, with no variation in low power electrical performance detected after testing. A 3 MW four-port switch has also been successfully tested at high RF power, and tests of a 6 MW hybrid power splitter are planned in the near future. Latest results will be presented. Plans for arc localization tests in a 60 m SRA transmission line run, and RF tests of Z0 = 50 Ω and Z0 = 20 Ω matching components with water-cooled inner conductors will also be discussed. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  8. Visualization of Available Power Transfer Capability in a Transmission System Using Morphological Techniques

    S. U. Prabha

    2009-01-01

    Full Text Available A morphological decimation technique has been proposed and implemented to analyze the available power transfer capability in a transmission power network. The method creates a graphical image of the power network with thickness of the lines proportional to their respective rated megavolt ampere (MVA capacity. Based on ac load flow solution, another image was created to represent the power flow in Megawatt (MW between the buses. Proper scaling procedure has been discussed for the construction of graphical images. The novelty of this research lies in the application of mathematical morphological techniques for decimating the created images. The image created for the MW capacities of the power lines were decimated into categories and grouped into different colors for better visualization. The multi-color image is superimposed on the input image which is created for the MVA capacity of the network. The proposed method has been tested on an IEEE test system. The results from the present approach can help the planner and operator in a power station, to get a better visualization of the power network. This is the first time this kind of multi-color visualization is presented and it can be used to find the optimal path for power transfer from one bus to another.

  9. Eri silkworm (Samia ricini), a non-mulberry host system for AcMNPV mediated expression of recombinant proteins.

    Hosamani, Madhusudan; Basagoudanavar, Suresh H; Sreenivasa, B P; Inumaru, Shigeki; Ballal, Chandish R; Venkataramanan, Ramamurthy

    2015-12-20

    The baculovirus expression system (BVES) based on Autographa californica nucleopolyhedrovirus (AcMNPV) is widely used for the expression of eukaryotic proteins. Several insect cells/larvae that are permissive to AcMNPV have been routinely used as hosts to express heterologous proteins. Domesticated Eri silkworm (Samia ricini), reared in many parts of India, Japan and China, is a non-mulberry silkworm. The present study shows that the Eri silkworm larvae are susceptible to intra-haemocoelical inoculation of AcMNPV. The virus replicates in the larva, as indicated by an increased viral loads in the haemolymph upon injection of a recombinant AcMNPV carrying green fluorescent protein gene. The virus showed localized replication in different tissues including the fat body, haemocytes, tracheal matrix and in the Malphigian tubules. The larval system was successfully used to express heterologous protein, by infecting with a recombinant AcMNPV carrying the 3ABC coding sequence of foot-and-mouth disease virus (FMDV). The study shows that the Eri silkworm larva can be a potential alternative bioreactor, for scaling up of the recombinant proteins employing the baculovirus system. PMID:26467714

  10. The Diagnostic System of A – 604 Automatic Transmission

    Czaban Jaroslaw

    2014-09-01

    Full Text Available Automatic gearbox gains increasing popularity in Europe. Little interest in diagnosis of such type of transmission in Poland results from the fact of small share in the whole market of operated cars, so there is a lack of availability of special diagnostic devices. These factors cause issues of expensive repairs, often involving a replacement of subassembly to new or aftermarket one. To a small extent some prophylactic diagnostic tests are conducted, which can eliminate future gearbox system failures. In the paper, the proposition of diagnostic system of popular A - 604 gearbox was presented. The authors are seeking for the possibility of using such type of devices to functional elaboration of gearboxes after renovation. The built system pursues the drive of the researched object, connected with simulated load, where special controller, replacing the original one, is responsible for controlling gearbox operation. This way is used to evaluate the mechanic and hydraulic parts' state. Analysis of signal runs, registered during measurements lets conclude about operation correctness, where as comparison with stock data verifies the technical state of an automatic gearbox.

  11. A portable wireless power transmission system for video capsule endoscopes.

    Shi, Yu; Yan, Guozheng; Zhu, Bingquan; Liu, Gang

    2015-01-01

    Wireless power transmission (WPT) technology can solve the energy shortage problem of the video capsule endoscope (VCE) powered by button batteries, but the fixed platform limited its clinical application. This paper presents a portable WPT system for VCE. Besides portability, power transfer efficiency and stability are considered as the main indexes of optimization design of the system, which consists of the transmitting coil structure, portable control box, operating frequency, magnetic core and winding of receiving coil. Upon the above principles, the correlation parameters are measured, compared and chosen. Finally, through experiments on the platform, the methods are tested and evaluated. In the gastrointestinal tract of small pig, the VCE is supplied with sufficient energy by the WPT system, and the energy conversion efficiency is 2.8%. The video obtained is clear with a resolution of 320×240 and a frame rate of 30 frames per second. The experiments verify the feasibility of design scheme, and further improvement direction is discussed. PMID:26405939

  12. A Series-LC-Filtered Active Damper with Grid Disturbance Rejection for AC Power-Electronics-Based Power Systems

    Wang, Xiongfei; Pang, Ying; Loh, Poh Chiang;

    2015-01-01

    This letter proposes an active damper with a series LC filter for suppressing resonances in an ac power-electronics-based power system. The added series filter capacitor helps to withstand most of the system voltage, hence, allowing a lower rated converter to be used for implementing the active...

  13. Power System Stability Improvement of Long Transmission Line System by Using Static Var Compensator (SVC)

    Pardeep Singh Virk

    2013-01-01

    Power system stability is defined as the ability of power system to preserve it’s steady stability or recover the initial steady state after any deviation of the system’s operation. This paper will discuss how SVC has successfully been applied to control dynamic performance of transmission system and regulate the system voltage effectively. Present time power systems are being operated nearer to their stability limits due to economic and environmental reasons. Maintaining a stable and secure ...

  14. Fast Decoupled Power Flow for Power System with High Voltage Direct Current Transmission Line System

    Prechanon Kumkratug

    2010-01-01

    Problem statement: High voltage direct current transmission line system has been widely applied for control power flow in power system. The power flow analysis was the one of powerful tools by which the power system equipped was analyzed both for planning and operation strategies. Approach: This study presented the method to analyze power flow of power system consisted of HVDC system. HVDC was modeled as the complex power injections. The presented complex power injected was incorporated into ...

  15. Numerical estimation of AC loss in superconductors with ripple current

    Highlights: •The loss energy density with ripple current is numerically calculated. •Irie–Yamafuji model is used for magnetic field dependence of critical current. •Calculated result of cylindrical superconductor agrees with theoretical result. •AC loss of strip superconductor becomes large at small ripple current amplitude. •Strip superconductor should be used as a form of hollow cylinder to reduce AC loss. -- Abstract: The loss energy density (AC loss) with ripple current is numerically calculated by finite element method for cylindrical and strip superconductors based on Irie–Yamafuji model in which the magnetic field dependence of the critical current density is taken into account for design of DC transmission cable system. It is confirmed that calculated result of the AC loss in the cylindrical superconductor with the ripple current agrees well with theoretical estimation which was reported in the previous work. On the contrary, the AC loss in the strip superconductor with the ripple current is obtained only by numerical calculation. It is found that the AC loss in the strip superconductor of the ripple current becomes larger than that without DC current at small ripple current amplitude, since the penetration depth of magnetic field becomes large. Therefore, it is recommended that strip superconductor is better to use as cylindrical hollow superconductor for DC transmission cable system to reduce the AC loss

  16. Robust Switching Control Strategy for a Transmission System with Unknown Backlash

    Qiang Ling; Zhe Yan; Honghai Shen; Jiquan Li; Yongyang Wang

    2014-01-01

    This paper proposes a robust switching control strategy for a transmission system with unknown backlash. Firstly, the adverse effects of backlash nonlinearity in the transmission system are analyzed. Then the backlash model and different operating modes of the transmission system with backlash are investigated. For each operating mode, an individual controller is designed to make the system robust against the unknown backlash and various frequencies of the input signal. Moreover, a supervisor...

  17. Magnetic behaviour of the UCuxGey system by AC magnetic susceptibility measurements

    We have analyzed the temperature dependence of the AC susceptibility, χac(T), of UCuxGey samples (0.800≤x, y≤1.00) applying various frequencies and magnetic field strengths up to 1 T. This was done in order to verify the reentrant ferromagnetic behaviour of UCuxGe and the antiferromagnetic behaviour of UCuGey previously observed by DC susceptibility experiments. Our χac results are discussed on the basis of existing theories. (orig.)

  18. Energy saving measures for automotive air conditioning (AC) system in the tropics

    Subiantoro, Alison; Ooi, Kim Tiow; Stimming, Ulrich

    2014-01-01

    Air conditioning (AC) is an integral component of modern cars in the tropics. However, AC usage in this region consumes a large amount of energy. In conventional internal combustion engine cars, it consumes up to 30% of the fuel, while in battery electric cars, AC may reduce the battery range by up to 40%. Fortunately, there are various ways to improve the efficiency of automotive ACs in the tropics. In this paper, three energy saving measures are discussed. These include a higher indoor temp...

  19. Harmonic Analysis of AC-DC Topologies and their Impacts on Power Systems

    Mukhtiar Ahmed Mahar

    2011-01-01

    Full Text Available Power Electronic Converters are commonly used in different applications because of high efficiency and low cost. Due to latest advancement in semiconductor devices it is difficult to draw the boundaries for applications of power electronic topologies. These topologies are variable structure systems and generate harmonics during the operation which will affect the power quality when are connected to system network. Rectifier is a big family of converters and used when ac-dc conversion is needed. These converters are widely used in distribution system. Therefore, it is necessary to predict the harmonic levels of these converters and also observe their impacts on system network. Pakistan now days facing serious energy crises specially, in power sector due to increase in load demand. To bridge the gap between load demand and generation of electricity, various steps are taken by power companies and government. The steps include the up gradation of existing power plants, generation of power from rental power plants, installation of renewable power sources, taking different steps of demand side management etc. But efforts of power companies on power quality is still lacking. This research work focuses on power quality of the system network. In this work, harmonics of single phase and three phase full bridge diode rectifiers are analyzed by using the fast fourier transform method of MATLAB. The effects of harmonics on the system network are also discussed.

  20. Transmission Needs In A Fully Renewable Pan-European Electricity System

    Rodriguez, Rolando A.; Bruun Andresen, Gorm; Becker, Sarah;

    2012-01-01

    Based on high-resolution weather and electrical load data, the transmission needs for a fully renewable pan-European electricity system are determined. The ideal cross-border transmission capacities turn out to be a factor 10 larger than those of today. A reduction of cross-border transmission...

  1. Progress and monitoring system on compression and transmission technologies of dynamic image

    The Toshiba Corporation developed a real-time dynamic image transmission matched with quality of transmission circuit by using MPEG-4 which was recent international standard system for the dynamic image coding system. Concretely, this system made possible on real-time dynamic image transmission even at transmission on wireless circuit such as portable telephone, PHS, wireless LAN, and so on, at viewpoint of the mobile communication. And, by using the wireless circuit, it could be built without any limit of transmission cable, to realize its layout-free establishment. In addition, this system uses only image for communication without using voice, and some devices were carried out to upgrade image and frame speed as possible. Here were described on outlines of transmission system and principle of detection MPEG-4, and function and application of monitoring system using this system. (G.K.)

  2. Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system.

    Arumugam, S; Manivannan, N; Murugeswari, A

    2007-06-01

    A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd(2)O(3), Er(2)O(3), and Fe(NH(4)SO(4))(2)6H(2)O], Fe(3)O(4), Gd metal, Dy metal, superconductor (YBa(2)Cu(3)O(7)), manganite (La(1.85)Ba(0.15)MnO(3)), and spin glass material (Pr(0.8)Sr(0.2)MnO(3)). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La(1.85)Ba(0.15)MnO(3) single crystal with P||c axis. The Curie temperature (T(c)) decreases as a function of pressure with P||c axis (dT(c)dP(||c axis)=-11.65 KGPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell. PMID:17614625

  3. Study on New Concatenated Code in WDM Optical Transmission Systems

    YUAN Jian-guo; JIANG Ze; MAO You-ju; YE Wen-wei

    2007-01-01

    A new concatenated code of RS(255,239)+BCH(2 040,1 930) code to be suitable for WDM optical transmission systems is proposed.The simulation results show that this new concatenated code,compared with the RS(255,239)+CSOC(k0/n0=6/7,J=8) code in ITU-T G.75.1,has a lower redundancy and better error-correction performance,furthermore,its net coding gain(NCG) is respectively 0.46 dB,0.43 dB more than that of RS(255,239)+CSOC(k0/n0 =6/7,J=8) code and BCH(3 860,3 824)+BCH(2 040,1 930) code in ITU-T G.75.1 at the third iteration for the bit error rate(BER) of 10-12.Therefore,the new super forward error correction(Super-FEC) concatenated code can be better used in ultra long-haul,ultra large-capacity and ultra high-speed WDM optical communication systems.

  4. Wheeling and transmission system service policy in North America

    This paper provides a review and discussion of the status of wheeling in the USA and Canada; the pros and cons of the new policies that are evolving and under consideration for wheeling and transmission access; specific case examples of some of the difficulties that have arisen; and the potential for new transmission technology. (author)

  5. Absence of Frequent Herpesvirus Transmission in a Nonhuman Primate Predator-Prey System in the Wild

    Murthy, Sripriya; Couacy-Hymann, Emmanuel; Metzger, Sonja; Nowak, Kathrin; De Nys, Helene; Boesch, Christophe; Wittig, Roman; Jarvis, Michael A.; Leendertz, Fabian; Ehlers, Bernhard

    2013-01-01

    Emergence of viruses into the human population by transmission from nonhuman primates (NHPs) represents a serious potential threat to human health that is primarily associated with the increased bushmeat trade. Transmission of RNA viruses across primate species appears to be relatively frequent. In contrast, DNA viruses appear to be largely host specific, suggesting low transmission potential. Herein, we use a primate predator-prey system to study the risk of herpesvirus transmission between ...

  6. Power Transmission from Large Offshore Wind Farms

    Pedersen, Jørgen Kaas

    1999-01-01

    transmitting the power can be by DC. At the moment it is possible to build self-commutating DC/AC-inverters up to about 150 kV. This paper will show a concept to a solution for a wind farm and a transmission system based on synchronous generators or a powerformer® with a rated voltage of 50 kV. The AC power...... to the AC grid.A simple comparison between this solution and a HVDC Light solution with induction generators will be done, as well as a few simulations showing the coherence between the speed of the synchronous generator and the duty cycle of the booster....

  7. Stability Analysis of Three-Phase AC Power Systems Based on Measured D-Q Frame Impedances

    Wen, Bo

    2015-01-01

    Small-signal stability is of great concern for distributed power systems with a large number of regulated power converters. These converters are constant-power loads (CPLs) exhibit a negative incremental input resistance within the output voltage regulation bandwidth. In the case of dc systems, design requirements for impedances that guarantee stability have been previously developed and are used in the design and specification of these systems. In terms of three-phase ac systems, a mathemati...

  8. Economic Aspect of HVDC Transmission System for Indonesia Consideration in Nuclear Power Development

    As a country with hundreds million people, Indonesia needs to generate large scale power and distribute it to thorough country to improve gross domestic product of the population. In the power transmission domain, the High Voltage Direct Current (HVDC) transmission system should be considered for the next decades concerning any technical and economical problems with HVAC transmission. HVDC transmission system is the answer for the Indonesian condition. This system can connect the high energy potential regions to the high energy demand regions. HVDC is the most efficient to transport energy from one region to another one region. Dismantling and removing assets costs are included to the estimated for capital costs, while the environmental and property costs are the costs of securing designations and resource consents, and valuation and legal advice for the HVDC investment. Although converter terminals are expensive however, for long transmissions HVDC system can compensate the costs over breakeven distance through very efficient transmission system. Efficiency of HVDC is appearing from conductor wire, supporting tower, low energy loses and free space used by route of the transmission line. HVDC system is also free from some problem, concerning stability, inductive and capacitive load components, phase differences and frequency system. In the economic aspect the HVDC capital costs for the transmission options comprise estimates of the cost to design, purchase and construct new HVDC transmission components. While operating and maintenance costs of HVDC assets comprise the costs for replacement the old existing overhead transmission lines, underground and submarine cables, and HVDC converter station components. (author)

  9. Power System Stability Improvement of Long Transmission Line System by Using Static Var Compensator (SVC

    Pardeep Singh Virk

    2013-09-01

    Full Text Available Power system stability is defined as the ability of power system to preserve it’s steady stability or recover the initial steady state after any deviation of the system’s operation. This paper will discuss how SVC has successfully been applied to control dynamic performance of transmission system and regulate the system voltage effectively. Present time power systems are being operated nearer to their stability limits due to economic and environmental reasons. Maintaining a stable and secure operation of a powersystem is therefore a very important and challenging issue. Shunt FACTS devices play an important role in improving the transient stability, increasing transmission capacity and damping low frequency oscillations. In this paper shunt FACTS device-SVC is used in a two area power system for improving the power system stability. MATLAB software has been used in this study.

  10. Development of an in-line filter to prevent intrusion of NO2 toxic vapors into A/C systems

    Meneghelli, Barry; Mcnulty, R. J.; Springer, Mike; Lueck, Dale E.

    1995-01-01

    The hypergolic propellant nitrogen tetroxide (N2O4 or NTO) is routinely used in spacecraft launched at Kennedy Space Center (KSC) and Cape Canaveral Air Station (CCAS). In the case of a catastrophic failure of the spacecraft, there would be a release of the unspent propellant in the form of a toxic cloud. Inhalation of this material at downwind concentrations which may be as high as 20 parts per million (ppm) for 30 minutes in duration, may produce irritation to the eyes, nose and respiratory tract. Studies at both KSC and CCAS have shown that the indoor concentrations of N2O4 during a toxic release may range from 1 to 15 ppm and depend on the air change rate (ACR) for a particular building and whether or not the air conditioning (A/C) system has been shut down or left in an operating mode. This project was initiated in order to assess how current A/C systems could be easily modified to prevent personnel from being exposed to toxic vapors. A sample system has been constructed to test the ability of several types of filter material to capture the N2O4 vapors prior to their infiltration into the A/C system. Test results will be presented which compare the efficiencies of standard A/C filters, water wash systems, and chemically impregnated filter material in taking toxic vapors out of the incoming air stream.

  11. Design of a data transmission system based on gigabit ethernet

    Yuan, Yongxin; Zhang, Lijun; Xu, Bin; Wang, Jiqiang; Yuan, Yonggang

    2013-09-01

    FPGA(Field-programmable gate array) is programmable device, characterized by high speed and reconfiguration. We could test the circuit programmed by HDL (Hardware Description Language). By observing results of simulations through ModelSim, developers could fix logic errors. Also, they could analyze performance of circuits by the results. In the system, we build the Gigabit Ethernet development platform based on a FPGA. This paper presents the technique of FPGA and Gigabit Ethernet, as well as relevant techniques. On the basis of merits and drawbacks of different design proposals and real demands, we take the EP3C10E144C8N chip belonging to the series of Cyclone III produced by Altera corp. as main controller chip. By the use of an AX88180 MAC chip produced by ASIX Electronics Corporation and a RTL8211E physical chip by Realtek Semiconductor Corporation, we build the development platform. At the receiving end, we capture data frames from the network adapter by winpcap programming and throw video data in the buffer. Considering large amounts of data in the real-time transportation, we design fixed-length queue as the primary structures for buffer. Size of a buffer unit is 32KB, which means that 32 packets can fill the buffer. When the buffer is full, we put the buffer unit to the end of the queue. We get data from buffer and hand it over to application process to display and store video data. When packet loss is detected by the system, log file will record it and thus we can check how many packets lose. The simulations by Quartus II and practical application proves that the system is stable, featuring high speed and low cost. It can be used in various high speed real-time transmission with little modification.

  12. Modelling of Hazards Effect on Safety Integrity of Open Transmission Systems

    Karol Rástočný; Mária Franeková; Peter Holečko; Iveta Zolotová

    2016-01-01

    The paper is concerned with safety appraisal of safety-related communication systems (SRComSs) with open transmission system, where except in addition to message transmission integrity also confidentiality is recommended to be provided. The authors focused on safety analysis of safety-related messages transmission secured using cryptographic and safety code mechanisms and on the possibilities of modelling safety-related industrial communication system, where a high safety integrity level SIL3...

  13. Vector control of three-phase AC machines system development in the practice

    Quang, Nguyen Phung

    2008-01-01

    Covers the area of vector control of 3-phase AC machines, in particular induction motors with squirrel-cage rotor, permanent excited synchronous motors and doubly-fed induction machines. This title summarizes the basic structure of a field-oriented controlled 3-phase AC drive and grid voltage orientated controlled wind power plant.

  14. Stress transmission through a model system of cohesionless elastic grains

    Da Silva M; Rajchenbach

    2000-08-17

    Understanding the mechanical properties of granular materials is important for applications in civil and chemical engineering, geophysical sciences and the food industry, as well as for the control or prevention of avalanches and landslides. Unlike continuous media, granular materials lack cohesion, and cannot resist tensile stresses. Current descriptions of the mechanical properties of collections of cohesionless grains have relied either on elasto-plastic models classically used in civil engineering, or on a recent model involving hyperbolic equations. The former models suggest that collections of elastic grains submitted to a compressive load will behave elastically. Here we present the results of an experiment on a two-dimensional model system--made of discrete square cells submitted to a point load--in which the region in which the stress is confined is photoelastically visualized as a parabola. These results, which can be interpreted within a statistical framework, demonstrate that the collective response of the pile contradicts the standard elastic predictions and supports a diffusive description of stress transmission. We expect that these findings will be applicable to problems in soil mechanics, such as the behaviour of cohesionless soils or sand piles. PMID:10963591

  15. Polar On-Line Acquisition Relay and Transmission System (POLARATS)

    Yuracko, K.

    2004-07-15

    POLARATS (Polar On-Line Acquisition Relay And Transmission System) is being developed by YAHSGS LLC (YAHSGS) and Oak Ridge National Laboratory (ORNL) to provide remote, unattended monitoring of environmental parameters under harsh environmental conditions. In particular, instrumental design and engineering is oriented towards protection of human health in the Arctic, and with the additional goal of advancing Arctic education and research. POLARATS will obtain and transmit environmental data from hardened monitoring devices deployed in locations important to understanding atmospheric and aquatic pollutant migration as it is biomagnified in Arctic food chains. An Internet- and personal computer (PC)-based educational module will provide real time sensor data, on-line educational content, and will be integrated with workbooks and textbooks for use in middle and high school science programs. The educational elements of POLARATS include an Internet-based educational module that will instruct students in the use of the data and how those data fit into changing Arctic environments and food chains. POLARATS will: (1) Enable students, members of the community, and scientific researchers to monitor local environmental conditions in real time over the Internet; and (2) Provide additional educational benefits through integration with middle- and high-school science curricula. Information will be relayed from POLARATS devices to classrooms and libraries along with custom-designed POLARATS teaching materials that will be integrated into existing curricula to enhance the educational benefits realized from the information obtained.

  16. System of failures diagnosis for energy transmission systems, using Petri nets

    An expert system of second generation was used integrating the inverse Petri nets (RPN) and the systems based on rules (rule-based system) for the accomplishment of a program in Visual Basic that helps in the obtaining of an opportune and fast analysis of transmission of energy at the time of happening a fault in anymore of its components (line or bus). The program is proven in a portion of system IEEE -118 standard bus test system, in which two extracted cases of literature are developed and are the obtained results. Finally tests realized with the method developed in the laboratory of machines of the national university of Colombia, Medellin campus, simulating a system of transmission with two lines and two buses

  17. Electric power transmission system: A new expansion scheme

    With the purpose of responding to the interconnection requirements among the main cities of the country, a company of public character was created, in charge of the planning and of the development of the national interconnected system (NIS), in such form that their work optimized the use of the available energy resources for the electricity supply and it improved the accounting levels and quality of the service. Starting from 1967, interconnection electric Corp., ISA, a very important task began in the development of methodologies and strategies of expansion of the INS that it allowed, in very short term, to connect the areas of Bogota the Atlantic Cost, Antioquia and the Cauca Valley and to develop important generation projects for the supply of electric power of the country. Then, the electric sector was reformed through the laws 142 and 143 of 1994, in search of the specialization of the business and in that sense, ISA is divided in two companies: ISAGEN that the activities degeneration and electric power commercialization, and ISA, company electric power transport, that it takes charge of the interconnection of the national system assumes. In connection with the execution of the transmission works and in the face of the possibility of lingering courts of energy, the law establishes that ISA will carry out the works that are needed and that the particular initiative doesn't develop. For that same time, it is considered that the planning should be carried out in an integral way, taking into account the requirements of the population's energy and its possibilities of supply and through programs and actions of appropriate use of the available energy resources. The UPME (Unit of Planning Miner Energetic) was created for assumes this work, so with their analyses they already offer signs to the state the investors, about the population's necessities and of the business opportunities, respectively

  18. Fiber-based orthogonal frequency division multiplexing transmission systems

    Heras Miguel, Eduardo

    2010-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) is the underlying modulation and transmission technology behind the success of modern wireless standards for both cellular, digital television and digital radio communications and also for Digital Subscriber Line wired access. Higher data rates to handle and the special nature of electronic-optic conversions and of optical wave propagation, can hold the key as to why it is only now that OFDM signal transmission over fiber is starting to take o...

  19. The vibration research of the AC dipole-girder system for CSNS/RCS

    Renhong, Liu; Huamin, Qu; Ling, Kang; Motuo, Wang; Guangyuan, Wang; Haijing, Wang

    2013-01-01

    China spallation neutron source(CSNS) is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts: an H- linac and a rapid cycling synchrotron(RCS). The rcs accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25 Hz. The AC dipole of the RCS is operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. The dipole magnet of RCS is active vibration equipment which is different with ground vibration accelerator. It is very important to design and research the dynamic characteristic of the dipole-girder system. This paper takes the dipole and girder as a specific model system, a method for researching the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The ansys simulation method plays a very important role in the girder structure design stage. With the m...

  20. Study for wireless power transmission of nuclear robot system

    Gasoline engine or electric motor is generally used for driving power of working. Gasoline tank is uncomfortable to carry. Battery capacity does not sustain long time working. Frequent moving back of robot to power charger or refueling tank is inconvenient. Long power cable connection occur winding problem if there are complex structures in walking way. We need some solution for continuous supply of robot energy at the free moving condition of robot. 'Wireless power transmission' is one of the solutions. Some experiment result to transmit wireless power to moving robot is described herein. To find possible wireless power transmission method for nuclear robot, wireless power transmission tests were performed. As result of these tests, it was confirmed that wireless power transmission by using dipole and mat type magnetic induction were possible. As result of flying robot experiment, it was realized that development of light weight core for receiver and wave reflection device for high directional transmitter are necessary for practical use of the dipole type wireless power transmission. Small size core and high directional transmitter will be next target. Mat type wireless power transmission is regarded as useful for robot power charging station in the inside containment

  1. Photonic Crystal Fibres as the Transmission Medium for Future Optical Communication Systems

    Zsigri, Beata

    2006-01-01

    air-guiding photonic bandgap fibres (AG-PBGFs) and their system applications. The first and currently only reported data transmission over AG-PBGF is described. The potentials and current limitations of AG-PBGFs as transmission fibres are discussed. A polarisation delay interferometer, exploiting the...... begun only recently. This thesis follows the evolution of PCFs as transmission media from the beginning up to now and presents state-of-the-art results of their various possible system applications. Index guiding PCFs have been investigated for transmission purposes. In this thesis, some of the initial...... transmission experiments comprising PCFs are presented. Among others, the first reported 10 Gbit/s transmission over 5.6 km PCF is described. The total transmission distance over index guiding PCF is increased to 57.6 km, more than four times longer than the achievable lengths of the date. The total capacity...

  2. Line Capacity Expansion and Transmission Switching in Power Systems With Large-Scale Wind Power

    Villumsen, Jonas Christoffer; Bronmo, Geir; Philpott, Andy B.

    2013-01-01

    In 2020 electricity production from wind power should constitute nearly 50% of electricity demand in Denmark. In this paper we look at optimal expansion of the transmission network in order to integrate 50% wind power in the system, while minimizing total fixed investment cost and expected cost...... of power generation. We allow for active switching of transmission elements to reduce congestion effects caused by Kirchhoff's voltage law. Results show that actively switching transmission lines may yield a better utilization of transmission networks with large-scale wind power and increase wind power...... penetration. Furthermore, it is shown that transmission switching is likely to affect the optimal line capacity expansion plan....

  3. Wavelet Based Fault Detection, Classification in Transmission System with TCSC Controllers

    G.Satyanarayana,

    2015-08-01

    Full Text Available This paper presents simulation results of the application of distance relays for the protection of transmission systems employing flexible alternating current transmission controllers such as Thyristor Controlled Series Capacitor (TCSC. The complete digital simulation of TCSC within a transmission system is performed in the MATLAB/Simulink environment using the Power System Block set (PSB. This paper presents an efficient method based on wavelet transforms both fault detection and classification which is almost independent of fault impedance, fault location and fault inception angle of transmission line fault currents with FACTS controllers.

  4. Simulation Study on Coil Design of Wireless Power Transfer System for Optimal Transmission Efficiency

    Hao Qiang

    2013-05-01

    Full Text Available As an emerging research field, Wireless Power Transfer (WPT has attracted wide spread attention recently. In this study, the coil design of WPT system for optimal transmission efficiency is investigated. We deduce Tthe design criteria are deduced to meet various conditions of transmission distance and load. The results of simulation and experiment show the transmission efficiency from transmitting coil to receiving coil can keep high when the corresponding optimal condition is achieved. Thusen it can improve the overall transmission efficiency of the WPT system and it makes it suitable for the practical application of WPT system.

  5. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  6. Investigate the Performance of LG 00 Mode in Cost Effective Hybrid Radio over Multimode Transmission System

    Pardeep Kaur; Rajbir Kaur

    2014-01-01

    Radio over fiber (RoF) technology composed for apprehension of future high performance integrated networks and future broadband networks. Multimode fiber links can offer a convenient approach for low cost and short Radio over Fiber (RoF) systems. This work is based on the cost effective radio over multimode transmission system (Ro-MMF) for long reach transmission. Error free transmission of 10 Gbps data with 10 GHz radio signal over multimode fiber link successfully demonstrat...

  7. HVDC: A key solution in future transmission systems

    Heyman, Olof H.; Weimers, Lars; Bohl, Mie-Lotte

    2010-09-15

    With the transition of power grids, based on sustainable generation, HVDC is a key technology with new applications. This includes connection of remote wind parks and strengthening of existing AC grids. In addition, traditional applications, such as bulk hydropower transfer and interconnections between regions, play a major role in our transition to sustainable generation and the associated grids. The technology for regional grids with a limited number of nodes is already in place and commercial projects are commissioned. For extensive grids, development and verification are ongoing in parallel to industry standards being discussed in groups such as ENTSO-E and CIGRE.

  8. Carbon footprint of the Danish electricity transmission and distribution systems

    Turconi, Roberto; Astrup, Thomas Fruergaard

    likely grow. Several studies are available on renewable energy technologies, but only a few on transmission of electricity, and none on its distribution. This study provides life cycle inventory data for electricity distribution networks, and a life cycle GHG accounting of the Danish T&D networks. The......The electricity sector is among the main sources of greenhouse gas (GHG) emissions; today, those are mainly due to combustion of fossil fuels, but with increasing renewable sources the importance of infrastructures both in electricity generation and in transmission and distribution (T&D) will...... relevant auxiliary infrastructures. Electricity T&D provided respectively 29 and 17 gCO2e/kWh, mainly related to power losses. Emissions from distribution were larger than those from transmission, because of higher losses and higher complexity and material consumption. Large differences were found between...

  9. 47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

    2010-10-01

    ... translator transmission system facilities. (a) A digital low power TV or TV translator station shall operate... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital low power TV and TV translator transmission system facilities. 74.795 Section 74.795 Telecommunication FEDERAL COMMUNICATIONS...

  10. Tuning of JET transmission line/antenna system during ICRH

    The launched toroidal wave spectrum for ICRH and ICRH current drive is controlled by the phasing of the antenna currents. This causes imbalance in the transmission lines, which makes it more difficult to use the full power of the ICRH generators. Further, the generators are sensitive to the amount of reflected power. To reduce the amount of reflected power the transmission lines have to be constantly tuned. To study the tuning three models of the antenna are developed and compared with experimental results. A method is suggested which enables better usage of the generated power using a power correction unit to evenly distribute the power load between the generators. 4 refs, 24 figs

  11. Preliminary survey of integrated monitoring system for transmission liens. Sodensen sogo kanshi system no yobi kento

    Sasano, Takao; Nishiyama, Fumihiko

    1988-04-01

    The integrated monitoring system of transmission lines utilizing ground wire with built-in optical fibres(OPGW) which was put to practical use was surveyed. The overhead transmission lines have potential to be impeded supply owing to the line exposure to severe natural envioronment or by the change of surrounding environment such as trees, buildings under lines and ground or by deterioration of equipments. This report describes the system to monitor integrally the transmission lines by using OPGW or sensor technology to maintain and operate with higher reliability and lower cost and to reflect in the design, except the conventional maintenance and checking. The effect to foresee and prevent accidents is expected from this system, but the regional difference must be considered. This system can provide continously reliable monitoring, collection of maintenance informations and operation support and further can provide accident informations to be used in the design through the evaluation. It is necessary to use highly reliable repeaters for optical informations, protect instruments under intense field, prevent malfunction and develop the auto-movable robot for taking picture and local weather prediction system in order to realize this system. (5 figs, 6 tabs, 8 refs)

  12. Optimization approach to unified AC/DC power flow applied to traction systems with catenary voltage constraints

    Coto García, Manuel; Arboleya Arboleya, Pablo; González Morán, Cristina

    2013-01-01

    This paper presents two innovative contributions related to the combined AC/DC power ow in railway power supply systems (RPSS). First, most of the power ow equations (the linear ones) are expressed in a compact matrix form by using graph theory based protocol. Such approach simpli- es the statement of the uni ed power ow problem and allows the train motion to be modeled without varying the system topology. Second, the problem is formulated as an Optimization Pro...

  13. Numerical and experimental analysis of structure-borne sound transmission in coupled systems

    Cao, Xiaodong; Backhaus, Stefan-Georg; Scheidl, Rudolf; Rembe, Christian

    2016-06-01

    The vibration-power transmission is often applied as a quantity to describe the structure-borne sound transmission in a vibration system and is, therefore, of major interest for machine manufactures. Well-developed theories about power transfer for multi-point coupled systems exist, especially, for structure-borne sound characterization. However, a theoretic analysis of area coupled systems is still a research topic because a direct measurement of vibration-power transmission in the contact interface for such systems is not possible. This paper introduces a strategy to investigate the vibration power transmission in such systems by using a finite element model which is updated by the so-called "model updating technique" based on experimental modal analysis, which is performed by a laser scanning Doppler vibrometer, in opposite to conventionally by accelerometer. The strategy is demonstrated on a simple test assembly and the estimated power transmission is derived.

  14. Design and Realization of Phased Array Radar Optical Fiber Transmission System

    HU Shan-qing; LIU Feng; LONG Teng

    2007-01-01

    One optical fiber transmission system is designed.The modularization optical fiber transmission adapters were utilized in the system,so the system structure could be flexibly scalable.The sub-array adapter and signal processor adapter were designed and realized utilizing the new field programmable gate array (FPGA) which could drive the optical transceiver.The transmission agreement was designed based on the data stream.In order to solve the signal synchronization problem of the optical fiber transmitted phased array radar,a method named synchronous clock was designed.The fiber transmission error code rate of the system was zero with an experimental transmission velocity of 800 Mbit/s.The phased array radar system has detected the airplane target,thus validated the feasibility of the design method.

  15. Parameter design and performance analysis of zero inertia continuously variable transmission system

    胡建军; 吉毅; 晏玖江

    2015-01-01

    In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission (CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.

  16. PROXY-BASED PATCHING STREAM TRANSMISSION STRATEGY IN MOBILE STREAMING MEDIA SYSTEM

    Liao Jianxin; Lei Zhengxiong; Ma Xutao; Zhu Xiaomin

    2006-01-01

    A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strategy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.

  17. An electrochemical study of corrosion protection by primer-topcoat systems on 4130 steel with ac impedance and dc methods

    Mendrek, M. J.; Higgins, R. H.; Danford, M. D.

    1988-01-01

    To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac impedance method is applied to six systems of primer coated and primer topcoated 4130 steel. Two primers were used: a zinc-rich epoxy primer and a red lead oxide epoxy primer. The epoxy-polyamine topcoat was used in four of the systems. The EG and G-PARC Model 368 ac impedance measurement system, along with dc measurements with the same system using the polarization resistance method, were used to monitor changing properties of coated 4230 steel disks immersed in 3.5 percent NaCl solutions buffered at pH 5.4 over periods of 40 to 60 days. The corrosion system can be represented by an electronic analog called an equivalent circuit consisting of resistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for the resistors and capacitors, that can be assigned in the equivalent circuit following a least-squares analysis of the data, describe changes that occur on the corroding metal surface and in the protective coatings. Two equivalent circuits have been determined that predict the correct Bode phase and magnitude of the experimental sample at different immersion times. The dc corrosion current density data are related to equivalent circuit element parameters. Methods for determining corrosion rate with ac impedance parameters are verified by the dc method.

  18. Virtual Pipeline System Testbed to Optimize the U.S. Natural Gas Transmission Pipeline System

    Kirby S. Chapman; Prakash Krishniswami; Virg Wallentine; Mohammed Abbaspour; Revathi Ranganathan; Ravi Addanki; Jeet Sengupta; Liubo Chen

    2005-06-01

    The goal of this project is to develop a Virtual Pipeline System Testbed (VPST) for natural gas transmission. This study uses a fully implicit finite difference method to analyze transient, nonisothermal compressible gas flow through a gas pipeline system. The inertia term of the momentum equation is included in the analysis. The testbed simulate compressor stations, the pipe that connects these compressor stations, the supply sources, and the end-user demand markets. The compressor station is described by identifying the make, model, and number of engines, gas turbines, and compressors. System operators and engineers can analyze the impact of system changes on the dynamic deliverability of gas and on the environment.

  19. Reliability evaluation of emergency AC power systems based on operating experience at U.S. nuclear power plants

    The reliability of emergency AC power Systems has been under study at the U.S. Nuclear Regulatory Commission and by its contractors for several years. This paper provides the results of work recently performed to evaluate past U.S. nuclear power plant emergency AC power System reliability performance using system level data. Operating experience involving multiple diesel generator failures, unavailabilities, and simultaneous occurrences of failures and out of service diesel generators were used to evaluate reliability performance at individual nuclear power plants covering a 9 year period from 1976 through 1984. The number and nature of failures and distributions of reliability evaluation results are provided. The results show that plant specific performance varied considerably during the period with a large number achieving high reliability performance and a smaller number accounting for lower levels of reliability performance. (author)

  20. Initial assessment: electromagnetic compatibility aspects of proposed SPS Microwave Power Transmission System (MPTS) operations

    1978-02-01

    An analysis of major concerns with regard to the effects on radio and electronic systems by the proposed Microwave Power Transmission System for transmitting power from a satellite solar power station to earth is presented. (LCL)

  1. Modeling and simulation of the transmission system for a chainless electric bicycle

    Garcia Farreny, Alex

    2015-01-01

    This project, entitled Modeling and Simulation of the Transmission System for a Chainless Electric Bicycle, consists in the design of the controllers’ logics governing a chainless electric bicycle’s transmission in order to accomplish certain behavior in front of inputs such as pedaling torque, slope gradient, frontal wind, gear selected, etc. To better understand it, a chainless electric bicycle replaces the conventional mechanical transmission (chain) by two electric mac...

  2. Study on protection scheme using SFCL for transmission system with Thyristor Controlled Series Capacitor

    Huh, Jae-Sun; Moon, Won-Sik; Kim, Jae-Chul

    2015-11-01

    In this paper, we propose a protection scheme using a superconducting fault current limiter (SFCL) for the power transmission system with Thyristor Controlled Series Capacitor (TCSC). TCSC can lead effectiveness such as power flow control, increase in transmission capacity, and improvement for system transient phenomena. But, because this has same effect to the reducing series impedances in transmission system, there are serious problem such as increase in fault current, transient stability deterioration and series voltage stress of TCSC in the transmission line. The proposed protection scheme using the SFCL into TCSC configuration can mitigate these problems. In addition, SFCL can be expected to protect the TCSC from a large transient current generated by lightning or switching surge in power transmission system. To verify the effect of the proposed protection scheme, PSCAD/EMTDC is used. From simulation result, we had good results for fault current limitation and insulating protection of TCSC.

  3. 77 FR 4292 - Midwest Independent Transmission System Operator, Inc.; Notice of Filing of Response to Data Request

    2012-01-27

    ... Energy Regulatory Commission Midwest Independent Transmission System Operator, Inc.; Notice of Filing of Response to Data Request Take notice that on January 19, 2012, Midwest Independent Transmission System... representatives of Transmission Owners and Non-Transmission Owners, MISO Advisory Committee participants, and...

  4. The influence of transmission system disturbances on the dynamic behaviour of a wind park

    Rui CASTRO; Jesus, J.M. Ferreira; Estanqueiro, Ana; Aguiar, Ricardo; Saraiva, J. A. Gil

    1993-01-01

    In this paper an integrated non-linear model of both the wind park and the interconnecction network is presented. The model is an integartion of model previously developed for each componenet of the system, namely wind turbines, induction generators, reactive power compensation system, transformers, feeder and possible local loads connected to the feeder. In order to draw some conclusions regarding the interaction between wind parks and the existing a.c. system, some case studies have been pe...

  5. Voltage Balancing Method on Expert System for 51-Level MMC in High Voltage Direct Current Transmission

    Yong Chen; Xu Zhang

    2016-01-01

    The Modular Multilevel Converters (MMC) have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter) transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the f...

  6. Modeling and simulation of a transcutaneous energy transmission system used in artificial organ implants.

    Fang, Wan; Liu, Wei; Qian, Jie; Tang, Houjun; Ye, Pengsheng

    2009-12-01

    We present a mathematical model to simulate transcutaneous energy transmission systems. Treating such systems as resonant power electronic converters, we develop the equivalent circuit equations, for which the circuit variables are then expanded as Fourier series and a multi-frequency averaging method was applied. Keeping terms up to first-order, the analysis produces a dynamic and harmonic model describing these energy transmission systems. With appropriate values for the circuit parameters, numerical results are compared with those of the exact time domain model. This comparison verifies that our model can adequately represent to first-order such energy-transmission systems. PMID:19958349

  7. A Stream Control Transmission Protocol Based OAM System of 3G Cellular Network

    2005-01-01

    OAM (Operations, Administration and Maintenance) system is a very important component of 3G cellular network. In order to acquire overall management, fast response and steady operation, an SCTP (Stream Control Transmission Protocol) based OAM, i. e. , SOAM system was proposed. SOAM implements new characters of SCTP such as multi-stream, enforced SACK and heartbeat mechanism on its transport layer. These characters help SOAM decrease the message transmission delay and accelerate the link failure detection. Besides, a new component named SOAM agent was introduced to improve the operation efficiency of SOAM. The experimental results prove the proposed SOAM system achieves better performance on signaling transmission compared with conventional TCP based OAM system.

  8. Transmission needs across a fully renewable European power system

    Rodriguez, Rolando A; Andresen, Gorm B; Heide, Dominik; Greiner, Martin

    2013-01-01

    The residual load and excess power generation of 27 European countries with a 100% penetration of variable renewable energy sources are explored in order to quantify the benefit of power transmission between countries. Estimates are based on extensive weather data, which allows for modelling of hourly mismatches between the demand and renewable generation from wind and solar photovoltaics. For separated countries, balancing is required to cover around 24% of the total annual energy consumption. This number can be reduced down to 15% once all countries are networked together with uncon- strained interconnectors. The reduction represents the maximum possible benefit of transmission for the countries. The total Net Transfer Capacity of the unconstrained interconnectors is roughly twelve times larger than current values. However, constrained interconnector capacities six times larger than the current values are found to provide 97% of the maximum possible benefit of cooperation. This motivates a detailed investig...

  9. HVDC transmission from nuclear power plant

    The HVDC transmission directly from nuclear power plants is one of the patterns of long distance and large capacity HVDC transmission systems. In this report, the double pole, two-circuit HVDC transmission from a BWR nuclear power plant is considered, and the dynamic response characteristics due to the faults in dc line and ac line of inverter side are analyzed, to clarify the dynamic characteristics of the BWR nuclear power plant and dc system due to system faults and the effects of dc power control to prevent reactor scram. (1) In the instantaneous earthing fault of one dc line, the reactor is not scrammed by start-up within 0.8 sec. (2) When the earthing fault continues, power transmission drops to 75% by suspending the faulty pole, and the reactor is scrammed. (3) In the instantaneous ground fault of 2 dc lines, the reactor is not scrammed if the faulty dc lines are started up within 0.4 sec. (4) In the existing control of dc lines, the reactor is scrammed when the ac voltage at an ac-dc connection point largely drops due to ac failure. (J.P.N.)

  10. Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

    Xiupu Zhang; Ran Zhu; Dongyan Shen; Taijun Liu

    2014-01-01

    Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelen...

  11. HIV Transmission in a State Prison System, 1988–2005

    Krishna Jafa; Peter McElroy; Lisa Fitzpatrick; Borkowf, Craig B.; Robin Macgowan; Andrew Margolis; Ken Robbins; Ae Saekhou Youngpairoj; Dale Stratford; Alan Greenberg; Jennifer Taussig; R Luke Shouse; Madeleine Lamarre; Eleanor McLellan-Lemal; Walid Heneine

    2009-01-01

    INTRODUCTION: HIV prevalence among state prison inmates in the United States is more than five times higher than among nonincarcerated persons, but HIV transmission within U.S. prisons is sparsely documented. We investigated 88 HIV seroconversions reported from 1988-2005 among male Georgia prison inmates. METHODS: We analyzed medical and administrative data to describe seroconverters' HIV testing histories and performed a case-crossover analysis of their risks before and after HIV diagnosis. ...

  12. Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

    Xiupu Zhang

    2014-11-01

    Full Text Available Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelength, optical channelization and the others, implemented in optical domain, to suppress both even and odd order nonlinear distortion components, such as second and third order. Digital predistortion has been a widely used linearization method for RF power amplifiers. However, digital linearization that requires analog to digital converter is severely limited to hundreds of MHz bandwidth. Instead, analog and optical linearization provide broadband linearization with up to tens of GHz. Therefore, for broadband radio over fiber transmission that can be used for future broadband cloud radio access networks, analog and optical linearization are more appropriate than digital linearization. Generally speaking, both analog and optical linearization are able to improve spur-free dynamic range greater than 10 dB over tens of GHz. In order for current digital linearization to be used for broadband radio over fiber transmission, the reduced linearization complexity and increased linearization bandwidth are required. Moreover, some digital linearization methods in which the complexity can be reduced, such as Hammerstein type, may be more promising and require further investigation.

  13. Transmission system planning in competitive and restructured environment: part-1

    In restructured environment, competitive markets expose transmission planners to new uncertainties. These are handled using a decision analysis approach whose key contribution is quantifying, minimizing risk with least cost effective plans. Power utility worldwide is under the process of disintegration these days. Now, it is the need of time that existing trends should be changed with the new ones in competitive restructured environment to escape from the present situation and enter into a new set up which is more reliable both from service and stability point of view. Traditionally, transmission planning used to be done by a state owned vertically integrated utility. This type of control on utilities is going to be diminished in coming restructured environment. In restructured environment, open access and on non-discriminatory basis clearly explains its importance including the aspects which gives better and more reliable and stable service in addition to future expansion provisions along with the role of private sector, but not affecting the country's security at any cost. A proper regulatory body must check the activities of private set up transmission planners and also it is must be for private sector to act upon the rules provided by the regulatory authority of that country. The are bound to act upon the guidelines provided by that Regulatory Authority. (author)

  14. Damping effects of Supplementary Control Signals for Enhancement of Transient Stability in AC-DC Power Systems

    Uma Vani M

    2010-07-01

    Full Text Available This paper discusses the impact of HVDC on Power System Stability and proposes a novel controlmechanism to augment the system angle stability. The effectiveness of the proposed controller is demonstrated by asingle machine-infinite bus system example. The performance of this controller, in comparison to the conventionalP and P-I controllers, is found to be very effective as a supplementary PID controller in damping generator rotoroscillations. The supplementary controls using signals derived from the AC systems to modulate the DC quantitiesis presented in this paper.

  15. Communication protocol in chassis detecting wireless transmission system based on WiFi

    In chassis detecting wireless transmission system, the wireless network communication protocol plays a key role in the information exchange and synchronization between the host and chassis PDA. This paper presents a wireless network transmission protocol based on TCP/IP which makes the rules of info...

  16. EXPERIMENTAL INVESTIGATION OF TIME DELAYS DATA TRANSMISSION IN AUTOMATIC CONTROL SYSTEMS

    RYABENKIY Vladimir Mikhailovich; USHKARENKO Alexander Olegovich

    2015-01-01

    The method of statistical analysis of time-delay transmission of information and control packets over the network in automatic control systems are considered in this article. The results of measurements of time delays, which are obtained based on the analytic dependence of the probability density allow theoretically determine the time delays for data transmission.

  17. The integration of renewable energy sources into electric power transmission systems

    Barnes, P.R.; Dykas, W.P.; Kirby, B.J.; Purucker, S.L. [Oak Ridge National Lab., TN (United States); Lawler, J.S. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-07-01

    Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission upgrades beyond the construction of a substation to connect to the grid. Except in the Southwest, significant investment to strengthen transmission systems will be required to support the development of high-capacity renewable sources of 1000 MW or greater in areas remote from major load centers. Cost estimates for new transmission facilities to integrate and dispatch some of these high-capacity renewable sources ranged from several million dollars to approximately one billion dollars, with the latter figure an increase in total investment of 35%, assuming that the renewable source is the only user of the transmission facility.

  18. Wideband Analog Transmission System Based on the External Intensity Electro-Optic Modulator

    Jiri Svarny

    2016-01-01

    Full Text Available The work deals with design and integration of an analog electro-optic transmission system suitable for some specialized tasks of diagnostics and measurements. The system is based on principle of external intensity modulation of fiber guided laser radiation. Besides wideband and almost lossless transmission the system tolerates extreme length of the transmitting medium and ensures ultimate galvanic barrier between the input and output.

  19. Auxiliary control system for irradiation specimen automatic transmission based on configuration software

    Auxiliary control system realizes sequential control and trace display and automatic transmission for irradiated specimen, which bases on configuration software (MCGS) and industrial control computer as the control platform. The system uses digital I/O cards to establish system state detection and output control arrays. It is showed that the structure posses stable, reliable and security characteristics and well meets the needs of specimen transmission and controlling in industrial automation. (authors)

  20. Effect of energy harvesting network reactive support on transmission system voltage performance

    Cuffe, Paul; Smith, Paul; Keane, Andrew

    2011-01-01

    It is common to operate distributed generators (DGs) at fixed inductive power factors to overcome voltage rise constraints on distribution networks. This approach increases distribution system reactive power demand, which may strain transmission system reactive power resources at times of system-wide high DG output, particularly if such output displaces synchronous generators. If a number of adjacent DGs are connected to a transmission node in a clustered fashion via a dedicated energy ha...

  1. Transmission prices in the electric system. Technical constraints and economic efficiency

    This article analyses the two main models at the core of today's theoretical discussion on transmission pricing in electricity sectors under competition. The first aim of the paper is showing how technical constraints that characterise transmission systems may affect energy production and transmission and therefore the definition of the price system for using the electric grid. The second aim of the paper is showing how it is possible to suggest solutions, although not free from limitations, that can be used for an efficient management of electric systems characterised by generation and consumption sectors under competition

  2. Facts controllers in power transmission and distribution

    Padiyar, KR

    2007-01-01

    About the Book: The emerging technology of Flexible AC Transmission System (FACTS) enables planning and operation of power systems at minimum costs, without compromising security. This is based on modern high power electronic systems that provide fast controllability to ensure ''flexible'' operation under changing system conditions. This book presents a comprehensive treatment of the subject by discussing the operating principles, mathematical models, control design and issues that affect the applications. The concepts are explained often with illustrative examples and case studies. In partic

  3. Analyze and experiment on AC magnetic field's effect to fiber optic gyroscopes in compact stabilization control systems

    Zhang, Chao; Mao, Yao; Tian, Jing; Li, Zhijun

    2015-10-01

    Fiber optic gyroscopes (FOG) are getting more and more attention in areas such as stabilization control systems as they are all solid state and have a wide bandwidth. In stabilization systems that require wide bandwidth control, motors are usually used as actuating mechanism for active disturbance restrain. Voice coil motors (VCMs) are usually used in compact stabilization systems that require large torque and fast response. However, AC magnetic field, which can affect the output of FOG due to Faraday effect, will be generated during operation of VCMs. The frequency range affected by the AC magnetic field to the FOG's output is the same as VCMs drive signal frequency range, which is also exactly the stabilization system's working range. Therefore the effect of the AC magnetic field to FOGs must be evaluated to verify the feasibility of a stable system design that uses both FOGs and VCMs. In this article, the basic structure and operating principle of stabilization system is introduced. The influence of AC magnetic field to FOG is theoretically analyzed. The magnetic field generated by VCMs is numerically simulated based on the theory deduction of the magnetic field near energized wires. To verify the influence of the VCM generated magnetic field to the FOGs in practical designs, a simplified random fiber coil model is built for it's hard to accurately test the exact polarize axis's twisting rate in a fiber coil. The influence to the FOG's output of different random coil model is simulated and the result shows a same trend that the influence of the VCM's magnetic field to the FOG is reduced as the distance between the VCM and the FOG increasing. The influence of a VCM to a FOG with the same parameters is experimentally tested. In the Fourier transformed FOG data the same frequency point as the VCM drive signal frequency can be read. The result fit simulated result that as the distance increases, the influence decreases. The amplitude of the frequency point is just

  4. Research and Development of Engine-Generator Set Control System for Tracked Vehicle Electric Transmission System

    HUANG Ying; HUANG Qian; SUN Feng-chun; LIU Bo-lan; LIU Jia

    2007-01-01

    As an energy generating equipment, the engine-generator set supplies power to the electric transmission. Therefore, its control is one of the key technologies of electric vehicles. Based on the discussion about the demands to the engine-generator set in tracked vehicles, the detailed function of engine-generator and the control strategy are determined. The hardware and software of the control system are also developed and tested in a prototype vehicle. The experiment results show that the control system has good reliability and can satisfy the power requirements of vehicles under all operating conditions.

  5. Module Twelve: Series AC Resistive-Reactive Circuits; Basic Electricity and Electronics Individualized Learning System.

    Bureau of Naval Personnel, Washington, DC.

    The module covers series circuits which contain both resistive and reactive components and methods of solving these circuits for current, voltage, impedance, and phase angle. The module is divided into six lessons: voltage and impedance in AC (alternating current) series circuits, vector computations, rectangular and polar notation, variational…

  6. Modeling of leak detection system for high pressure transmission system of natural gas

    Gas Industry can be considered as one of the most important industries in the economy of any country. Safe Transportation of Gas is thus considered to be vital because interruption of Supply of Gas to consumers not only causes domestic problems but also loss of revenue to country. Now most of power generation Sector has switched over their system to Natural Gas. So, interruption of supply to this sector can cause a lot of problems. This paper has provided assessment of technology approach and formulated this approach for Leak Detection Model in High Pressure Transmission system for current and future operations, which will improve the efficiency of any transmission company to a great extent. This model can be extremely helpful in conditions of Rupture Emergencies or Leakage because of corrosive conditions of Pipeline to manage the situation of resources in pipeline network. Any exceptional readings or messages should alert the user to the fact that something is wrong with the system. Such a system helps a lot in the safe and efficient management of pipeline network. The data and information provided by the Leak Detection System applications will allow for efficient and safe pipeline operation maximizing profitability over the pipeline's service lifetime. (author)

  7. Formation of compounds in the quasi-binary systems AcX4-MX2 (Ac = Th, U; M = Ca, Sr, Ba, Eu, Ge, Sn, Pb; X = Br, I)

    T,x-phase diagrams of the systems ThI4-SnI2, ThI4-PbI2, ThI4-CaI2 and ThI4-SrI2 were established using thermoanalysis and X-ray methods. The only ternary compounds have a 1:1 composition. Further AcMX6 compounds (Ac: Th, U; M: Ca, Sr, Ba, Eu, Ge, Sn, Pb; X: Br, I) were synthesized and their structures investigated. Four structure types are found depending on the temperature and the Ac/M combinations. The structures of γ-ThSnI6 and β-ThSnI6 were determined with single crystal methods as representatives of a whole series of isotypic compounds. (orig.)

  8. A Study on the Application for Enhancing the Transmission Capability of the KEPCO Power System

    Kim, Young Han; Kwon, Tea Won; Whang, Jong Young; Lee, Gun Joon; Kim, Tae Hoon; Chang, Byung Hoon; Min, Wan Ki [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Park, Young Moon; Park, Jong Gun [Seoul National University, Seoul (Korea, Republic of); Kim, Gun Joong [Chungnam National University, Taejon (Korea, Republic of); Oh, Tae Kwu; Choi, Kwu Hyung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    Investigation of stability for power system in 2000 year and 2006 year by using the analysis of real power system. Comparative investigation of the conventional transmission line upgrading methods such as HVDC, HOP, new conductor scheme. Investigation of FACTS, the recent transmission line upgrading method, with respect to the aspect of technique and cost and effect analysis when this method is applied to real power system. Development of the evaluation method of transmission type that should be considered when above method is applied to real power system with respect to aspect of technique and cost. Development of a long-range plan for the transmission capacity upgrading and the evaluation method of reliability. (author).

  9. Transmission system planning in competitive and restructured environment - case study: part-1

    In continuation with previous paper, it is obvious that transmission planning in competitive and restructured environment is very important to have an efficient and economical power system / transmission network in changing trends globally. The recommendations give in part of this paper are implemented on a case study. The conclusions drawn by the study done in part clearly gives positive results in favor of transmission system planning in competitive and restructured environment to have open access and on non-discriminatory basis including the features of wheeling transactions and controlled by the regulatory body to monitor the activities of private set up specially from defense point of view and reliability and stability of the system. The results obtained in previous paper are going to be implemented on a study case. Results of application of transmission system planning in competitive and restructured environment is given at the end. (author)

  10. R and D of transmission lines for ECH system

    The performance of oversized transmission elements for millimeter waves is measured and compared with the calculation which is based on the superposition of plane wave (SPW) and on Fresnel approximation in the Huygens-Kirchhoff integral. Mode-conversion in the split waveguide is discussed from the viewpoint of on- and off-axes and 90-degrees elbow bend on phase correction is examined by using the SPW method. The design and experiment on the whispering gallery mode generator are described. A preliminary analysis of the rectangular waveguide with two corrugated plates and two plane walls is also carried out to obtain the Gaussian beam with a waist size of x-axis different from that of y-axis. (author)

  11. Massive WDM and TDM Soliton Transmission Systems : a ROSC Symposium

    2002-01-01

    This book summarizes the proceedings of the invited talks presented at the “International Symposium on Massive TDM and WDM Optical Soliton Tra- mission Systems” held in Kyoto during November 9–12, 1999. The symposium is the third of the series organized by Research Group for Optical Soliton C- munications (ROSC) chaired by Akira Hasegawa. The research group, ROSC, was established in Japan in April 1995 with a support of the Japanese Ministry of Post and Telecommunications to promote collaboration and information - change among communication service companies, communication industries and academic circles in the theory and application of optical solitons. The symposium attracted enthusiastic response from worldwide researchers in the field of soliton based communications and intensive discussions were made. In the symposium held in 1997, new concept of soliton transmission based on dispersion management of optical fibers were presented. This new soliton is now called the dispersion managed soliton. The p...

  12. Electrical transmission systems and smart grids selected entries from the encyclopedia of sustainability science and technology

    Begovic, Miroslav M

    2012-01-01

    Electric transmission networks are among the largest human-made engineering systems: For example, the transmission network in the United States covers over 300,000 km of lines and is served by 500 companies (electric utilities). In sharp contrast to the very incremental developments of the last century, transmission and control technologies experienced a major breakthrough at the beginning of the 21st century. The rapid growth of new energy generation technologies (renewables), significant advances in information processing applied to system monitoring, planning, operation, control, and protec

  13. Low pressure electrospray ionization system and process for effective transmission of ions

    Tang, Keqi; Page, Jason S.; Kelly, Ryan T.; Smith, Richard D.

    2010-03-02

    A system and method are disclosed that provide up to complete transmission of ions between coupled stages with low effective ion losses. A novel "interfaceless" electrospray ionization system is further described that operates the electrospray at a reduced pressure such that standard electrospray sample solutions can be directly sprayed into an electrodynamic ion funnel which provides ion focusing and transmission of ions into a mass analyzer.

  14. Simulation on Dual-stream Transmission System of Unmanned Tracked Armored Vehicle Using ADAMS

    Sun Wei

    2015-01-01

    Full Text Available For the dual-stream transmission system of unmanned tracked armored vehicle, simulation analysis is carried out. Using SolidWorks to establish three-dimensional model of its chassis, the result of the simulation is processed in AdAMS/Solver. The simulation results are showed in lines. Comparative analysis for each simulation lines is conducted, and it verifies the feasibility of the dual-stream transmission system.

  15. Training-based Channel Estimation for Signal Equalization and OPM in 16-QAM Optical Transmission Systems

    Pittalà, Fabio; Hauske, Fabian N.; Ye, Yabin; Tafur Monroy, Idelfonso; Nossek, Josef A.

    2012-01-01

    Efficient channel estimation for signal equalization and OPM based on short CAZAC sequences with QPSK and 8PSK constellation formats is demonstrated in a 224-Gb/s PDM 16-QAM optical linear transmission system.......Efficient channel estimation for signal equalization and OPM based on short CAZAC sequences with QPSK and 8PSK constellation formats is demonstrated in a 224-Gb/s PDM 16-QAM optical linear transmission system....

  16. Near-optimal order-reduced control for A/C (air-conditioning) system of EVs (electric vehicles)

    This work is aimed to investigate the regulation problem for thermal comfortableness and propose control strategies for cabin environment of EVs (electric vehicles) by constructing a reduced-scale A/C (air-conditioning) system which mainly consists of two modules: ECB (environmental control box) and AHU (air-handling unit). Temperature and humidity in the ECB can be regulated by AHU via cooling, heating, mixing air streams and adjusting speed of fans. To synthesize the near-optimal controllers, the mathematical model for the system thermodynamics is developed by employing the equivalent lumped heat capacity approach, energy/mass conservation principle and the heat transfer theories. In addition, from the clustering pattern of system eigenvalues, the thermodynamics of the interested system can evidently be characterized by two-time-scale property. That is, the studied system can be decoupled into two subsystems, slow mode and fast mode, by singular perturbation technique. As to the optimal control strategies for EVs, by taking thermal comfortableness, humidity and energy consumption all into account, a series of optimal controllers is synthesized on the base of the order-reduced thermodynamic model. The feedback control loop for the experimental test rig is examined and realized by the aid of the control system development kit dSPACE DS1104 and the commercial software MATLAB/Simulink. To sum up, the intensive computer simulations and experimental results verify that the performance of the near-optimal order-reduced control law is almost as superior as that of standard LQR (Linear-Quadratic Regulator). - Highlights: • A reduced-scale test rig for A/C (air-conditioning) system to imitate the temperature/humidity of cabin in EV (electric vehicle) is constructed. • The non-linear thermodynamic model of A/C system can be decoupled by singular perturbation technique. • The temperature/humidity in cabin is regulated to the desired values by proposed optimal

  17. Experimental Investigation on Surface Conditions of Conductors in AC Power Transmission Lines%交流输电线路导线表面状态的实验研究

    卞星明; 杨文言; 赵磊; 王黎明; 关志成

    2011-01-01

    导线表面状态是影响其电晕特性的重要因素,研究实际运行后导线的表面状态对输电线路的设计、运行都有着重要的理论意义.为此,选取了华北、华中和华南典型地区的500 kV交流输电线路导线及新导线样本进行了表面状态的研究.场发射环境扫描电子显微镜的实验结果表明:实际运行后导线的表面物质成分比新导线大大增加,表面形貌更加凹凸不平;非金属元素主要含有碳、氧、硅、硫,金属元素主要含有铝、铁、钙、钾、钠、镁.表面形貌仪的实验结果表明:与新导线相比,运行后导线的粗糙度增加,同一地区的导线表面粗糙度相差不大,随着运行时间的增加,导线表面粗糙程度有所提高.%The influence of conductor surface conditions on corona discharge is of great value to the design and operation of power transmission lines in power system. Six strands of the aged conductors acquired from 500 kV AC transmission lines in northern, central, southern China respectively and two strands of the new conductors China were used. The results of scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX) showed that the morphologies of the aged strands were greatly different from the new ones. The aged strands had been corrupted in the ambient atmospheric conditions during their long-term operating in power grid; many substances in the neighborhood of the conductors were also adhered to the surfaces as a result of the strong electric field and gravitational force. Therefore, the surfaces of the aged strands are much coarser and more uneven than the new ones. For the new strands, aluminum is the main component, there are few impurities. However, in the surface layer of the aged strands, there are many other elements, such as oxygen, carbon, silicon, sulfur, chlorine, kalium, calcium, zincum, natrium, iron, magnesium etc. Two basic roughness parameters Ra and Rq were introduced to express

  18. Error Assessment of Solar Irradiance Forecasts and AC Power from Energy Conversion Model in Grid-Connected Photovoltaic Systems

    Gianfranco Chicco

    2015-12-01

    Full Text Available Availability of effective estimation of the power profiles of photovoltaic systems is essential for studying how to increase the share of intermittent renewable sources in the electricity mix of many countries. For this purpose, weather forecasts, together with historical data of the meteorological quantities, provide fundamental information. The weak point of the forecasts depends on variable sky conditions, when the clouds successively cover and uncover the solar disc. This causes remarkable positive and negative variations in the irradiance pattern measured at the photovoltaic (PV site location. This paper starts from 1 to 3 days-ahead solar irradiance forecasts available during one year, with a few points for each day. These forecasts are interpolated to obtain more irradiance estimations per day. The estimated irradiance data are used to classify the sky conditions into clear, variable or cloudy. The results are compared with the outcomes of the same classification carried out with the irradiance measured in meteorological stations at two real PV sites. The occurrence of irradiance spikes in “broken cloud” conditions is identified and discussed. From the measured irradiance, the Alternating Current (AC power injected into the grid at two PV sites is estimated by using a PV energy conversion model. The AC power errors resulting from the PV model with respect to on-site AC power measurements are shown and discussed.

  19. A Sequential AC/DC Power Flow Algorithm for Networks Containing Multi-terminal VSC HVDC Systems

    Beerten, Jef; Cole, Stijn; Belmans, Ronnie

    2010-01-01

    In this paper, a sequential AC/DC power flow algorithm is proposed to solve networks containing Multi-terminal Voltage Source Converter High Voltage Direct Current (VSC MTDC) systems. In VSC HVDC technology, the converter losses add up to a significant fraction of the overall system losses. However, they are often neglected or not taken into account in a proper manner in VSC HVDC power flows. The algorithm put forward in this paper takes the converter losses into account using a generalized c...

  20. Dynamic interactions between asynchronous grids interconnected through an MTDC system

    Endegnanew, Atsede Gualu; Beerten, Jef; Uhlen, Kjetil

    2015-01-01

    The large-scale integration of renewable energy sources in the power system, combined with the need for an increased transmission capacity has led to a growing interest in multi-terminal high voltage dc (MTDC) grids. In the future, these grids will be integrated with different existing asynchronous ac grids, eventually resulting in hybrid AC/DC power systems. This paper investigates interactions between asynchronous ac grids in a hybrid AC/DC power system. In the study, a symmetrical monopola...

  1. Cost estimation of HVDC transmission system of Bangka’s NPP candidates

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different

  2. Cost estimation of HVDC transmission system of Bangka’s NPP candidates

    Liun, Edwaren, E-mail: edwaren@batan.go.id; Suparman, E-mail: edwaren@batan.go.id [Centre for Nuclear Energy Development, National Nuclear Energy Agency of Indonesia (Indonesia)

    2014-09-30

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different.

  3. High-voltage transmission tower-line system subjected to disaster loads

    LI Hongnan; BAI Haifeng

    2006-01-01

    The high-voltage power transmission system is an important lifeline structure. It is significant for wide researches on the features and ability of the system subjected to earthquake and environmental loads. The promising prosperity of the system has been demonstrated around the world. The corresponding advances of the system with respect to the mechanism of loading action, analytical methods, experimental research measurements, structural vibration control, fatigue damage, lifetime prediction, and design methods are comprehensively discussed herein. Finally, further research work on dynamic response characteristics of high-voltage transmission towerline system in the near future is predicted.

  4. Application of HSB color model in pseudo dual-energy X-ray transmission imaging system

    Comparing with the traditional mono-energy X-ray imaging inspection system, dual-energy X-ray transmission imaging system has the ability of simple object identification. It can automatically classify the materials into organic, inorganic and mixture signing with different colors. In order to enhance the object identification ability of dual-energy imaging system, HSB color model was applied in pseudo dual-energy X-ray transmission imaging system and the special method of color mapping was used for signing pixel colour in this paper. The experiments on 1/3 scale system show that the object identification ability is improved by using HSB color model. (authors)

  5. Optimisation of Transmission Systems by use of Phase Shifting Transformers

    Verboomen, J.

    2008-10-13

    In this thesis, transmission grids with PSTs (Phase Shifting Transformers) are investigated. In particular, the following goals are put forward: (a) The analysis and quantification of the impact of a PST on a meshed grid. This includes the development of models for the device; (b) The development of methods to obtain optimal coordination of several PSTs in a meshed grid. An objective function should be formulated, and an optimisation method must be adopted to solve the problem; and (c) The investigation of different strategies to use a PST. Chapter 2 gives a short overview of active power flow controlling devices. In chapter 3, a first step towards optimal PST coordination is taken. In chapter 4, metaheuristic optimisation methods are discussed. Chapter 5 introduces DC load flow approximations, leading to analytically closed equations that describe the relation between PST settings and active power flows. In chapter 6, some applications of the methods that are developed in earlier chapters are presented. Chapter 7 contains the conclusions of this thesis, as well as recommendations for future work.

  6. Investigations and system design for simultaneous energy and data transmission through inductively coupled resonances

    Schmidt, C.; Lloret Fuentes, E.; Buchholz, M.

    2015-11-01

    Wireless Power Transfer (WPT) with simultaneous data transmission through coupled magnetic resonators is investigated in this paper. The development of this system is dedicated to serve as a basis for applications in the field of Ambient Assisted Living (AAL), for example tracking vital parameters remotely, charge and control sensors and so on. Due to these different scenarios we consider, it is important to have a system which is reliable under the circumstance of changing positioning of the receiving device. State of the art radio systems would be able to handle this. Nevertheless, energy harvesting from far field sources is not sufficient to power the devices additionally on mid-range distances. For this reason, coupled magnetic resonant circuits are proposed as a promising alternative, although suffering from more complex positioning dependency. Based on measurements on a simple prototype system, an equivalent circuit description is used to model the transmission system dependent on different transmission distances and impedance matching conditions. Additionally, the simulation model is used to extract system parameters such as coupling coefficients, coil resistance and self-capacitance, which cannot be calculated in a simple and reliable way. Furthermore, a mathematical channel model based on the schematic model has been built in MATLAB©. It is used to point out the problems occurring in a transmission system with variable transmission distance, especially the change of the passband's centre frequency and its bandwidth. Existing solutions dealing with this distance dependent behaviour, namely the change of the transmission frequency dependent on distance and the addition of losses to the resonators to increase the bandwidth, are considered as not inventive. First, changing the transmission frequency increases the complexity in the data transmission system and would use a disproportional total bandwidth compared to the actually available bandwidth

  7. Peak Power Reduction in OFDM Systems for Multicarrier Transmission

    Sabhyata Uppal,; Sanjay Sharma

    2013-01-01

    The transmit signals in an OFDM system can have high peak values in the time domain since many subcarrier components are added via an IFFT operation. Therefore, OFDM systems are known to have a high PAPR (Peak-to-Average Power Ratio), compared with single-carrier systems. In fact, the high PAPR is one of the most detrimental aspects in the OFDM system, as it decreases the SQNR (Signal-to-Quantization Noise Ratio) of ADC (Analog-to-Digital Converter) and DAC (Digital-to-Analog Converter) while...

  8. Transmission System Vegetation Management Program. Draft Environmental Impact Statement

    Bonneville is responsible for maintaining a network of 24,000 kilometers (km) or 15,000 miles (mi.) of electric transmission lines and 350 substations in a region of diverse vegetation. This vegetation can interfere with electric power flow, pose safety problems for Bonneville and the public, and interfere with their ability to maintain these facilities. They need to (1) keep vegetation away from the electric facilities; (2) increase their program efficiency and consistency; (3) review herbicide use (under increased public scrutiny); and (4) maximize the range of tools they can use while minimizing environmental impact (Integrated Vegetation Management). This DEIS establishes Planning Steps for managing vegetation for specific projects (to be tiered to this EIS). In addition to No Action (current practice), alternatives are presented for Rights-of-way, Electric Yards, and Non-electric Facilities (landscaping, work yards). Four vegetation control methods are analyzed: manual, mechanical, herbicide, and biological. Also evaluated are 24 herbicide active ingredients and 4 herbicide application techniques (spot, localized, broadcast, and aerial). For rights-of-way, they consider three sets of alternatives: alternative management approaches (time-driven or establishing low-growing plant communities); alternative method packages; and, if herbicides are in a methods package, alternative vegetation selections (noxious weeds, deciduous, or any vegetation). For electric yards, one herbicide-use alternative is considered. For non-electric facilities, two method package alternatives are considered. For rights-of-way, the environmentally preferred alternative(s) would use manual, mechanical, and biological control methods, as well as spot and localized herbicide applications for noxious and deciduous plant species; the BPA-preferred alternative(s) would add broadcast and aerial herbicide applications, and would use herbicides on any vegetation. Both would favor a management

  9. Kansas Communication and Instruction System through Fiber-Optic Transmission.

    Kansas State Dept. of Education, Topeka.

    Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

  10. Precision-analog fiber-optic transmission system

    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters

  11. Modelling ac ripple currents in HTS coated conductors

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  12. Line-of-Sight MIMO for Next-Generation Microwave Transmission Systems

    Xianwei Gong; Zhifeng Yuan; Jun Xu; Liujun Hu

    2012-01-01

    Line-of-sight MIMQ (LoS MIMO) is not applicable in scattering wireless transmission scenarios, but it may be applied in LoS microwave transmission scenarios if antenna spacing (within transmit and/or receive arrays) is suitable and there is one hop distance. LoS MIMQ can improve channel capacity and performance of a transmission system. In this paper, we discuss factors affecting channel capacity and performance in LoS MIMO. We also discuss the feasibility LoS MIMO applications.

  13. Optimal transmission strategy for spatially correlated MIMO systems with channel statistical information

    ZHAO Zhen-shan; XU Guo-zhi

    2007-01-01

    In real multiple-input multiple-output (MIMO) systems, the perfect channel state information (CSI) may be costly or impossible to acquire. But the channel statistical information can be considered relatively stationary during long-term transmission.The statistical information can be obtained at the receiver and fed back to the transmitter and do not require frequent update. By exploiting channel mean and covariance information at the transmitter simultaneously, this paper investigates the optimal transmission strategy for spatially correlated MIMO channels. An upper bound of ergodic capacity is derived and taken as the performance criterion. Simulation results are also given to show the performance improvement of the optimal transmission strategy.

  14. Speed Control of DC Motor using AC/AC/DC Converter Based on Intelligent Techniques

    Rakan Kh Antar

    2013-05-01

    Full Text Available    This paper describes the application of ac/ac/dc and ac/dc converters to control the speed of a separately excited DC motor. Artificial neural network and PI controller are trained to select the desired values of firing angles for triggering thyristors of the ac/ac/dc and ac/dc bridge converters in order to control the speed of the dc motor at a desired value with constant and different load torques in order to obtain the best speed response. Simulation results show that the rising time for ac/dc and ac/ac/dc converters at 250rpm are reduced about 79% and 89% respectively, while delay time it reduced about 69% and 64% respectively. Therefore, speed response of the dc motor is more efficient for closed loop system compared with open loop also the response of ac/ac/dc converter is better than ac/dc converter.

  15. Analysis of effect of random perturbation on dynamic response of gear transmission system

    In order to investigate the effects of random perturbation of a low-frequency excitation caused by torque fluctuations, gear damping ratio, gear backlash, meshing frequency and meshing stiffness, the random dynamic model of a single pair of three-degree-of-freedom spur gear transmission system is established. With gear meshing frequency changing, the dynamic characteristics of the gear transmission system were analyzed by bifurcation diagram, phase diagram, time course diagram and Poincaré map of the system. The effects of random perturbation caused by a low-frequency excitation caused by torque fluctuations, gear damping ratio, gear backlash, meshing frequency and meshing stiffness were comparative analyzed. Numerical simulation shows that the gear transmission system with nonlinear clearance exists rich period-doubling bifurcation phenomenon. With the increasing of the gear meshing frequency, gear transmission system will be from the chaotic motion to periodic motion by inverse period-doubling bifurcation. The effect of the meshing frequency random perturbation on the gear transmission system movement is largest. On the contrary, the effect of the meshing stiffness random perturbation on the system is minimum

  16. Transmission performance of a 400 Gbit s−1 all-optical orthogonal frequency division multiplexing system

    The performance of a 400 Gbit s−1 all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system is researched with the effects of chromatic dispersion, fiber nonlinearities and amplified spontaneous emission (ASE) noise. The numerical simulation results show that the AO-OFDM system can provide a higher spectral efficiency (SE) and a better sensitivity than a dense wavelength division multiplexing (DWDM) system. The accumulated dispersion tolerance of the system reaches 330 ps nm−1. When transmitted over single-span 80 km single-mode fiber (SMF), AO-OFDM signals have a 1.5 dB power penalty at BER=10−3 due to the fiber Kerr nonlinearities, and the receiver sensitivity of the AO-OFDM system is obviously degraded with increasing incident optical power. In multispan transmission, the interaction of the fiber Kerr nonlinearity with the ASE noise is analyzed. A 1320 km maximum transmission distance is realized at 0 dBm incident optical power. The transmission discount due to the ASE noise and fiber nonlinearities in the AO-OFDM system is calculated. Fiber Kerr nonlinearities impose a greater limitation on the performance of the AO-OFDM system for long-distance transmission. All results clearly indicate the feasibility of AO-OFDM technology for next generation 400 Gbit s−1 fiber communication and multiservice networks. (paper)

  17. Research on WDM optical fiber transmission system based on fiber Raman amplifier

    Fei Xue(薛飞); Kun Qiu(邱昆); Yue Chen(陈玥)

    2003-01-01

    After wavelength division multiplexing (WDM) optical fiber transmission system based on fiber Raman amplifier (FRA) is investigated in detail, the influence of the collocation of dispersion compensation fiber (DCF), the dispersion coefficient, dispersion slope (DS), effective core area, nonlinear index, length of FRA, launch power and the bandwidth of Bessel filter on bit error rate (BER) is deduced. The influence of Rayleigh backscattering noise on optical signal noise ratio (OSNR) is also investigated, which affects the performance of long haul transmission badly. The result indicates that the broadband long haul transmission can be realized through the reasonable design of the fiber. The result is useful to the optimal design of the WDM optical fiber transmission system based on FRA.

  18. Increased Ac excision (iae): Arabidopsis thaliana mutations affecting Ac transposition

    The maize transposable element Ac is highly active in the heterologous hosts tobacco and tomato, but shows very much reduced levels of activity in Arabidopsis. A mutagenesis experiment was undertaken with the aim of identifying Arabidopsis host factors responsible for the observed low levels of Ac activity. Seed from a line carrying a single copy of the Ac element inserted into the streptomycin phosphotransferase (SPT) reporter fusion, and which displayed typically low levels of Ac activity, were mutagenized using gamma rays. Nineteen mutants displaying high levels of somatic Ac activity, as judged by their highly variegated phenotypes, were isolated after screening the M2 generation on streptomycin-containing medium. The mutations fall into two complementation groups, iae1 and iae2, are unlinked to the SPT::Ac locus and segregate in a Mendelian fashion. The iae1 mutation is recessive and the iae2 mutation is semi-dominant. The iae1 and iae2 mutants show 550- and 70-fold increases, respectively, in the average number of Ac excision sectors per cotyledon. The IAE1 locus maps to chromosome 2, whereas the SPT::Ac reporter maps to chromosome 3. A molecular study of Ac activity in the iae1 mutant confirmed the very high levels of Ac excision predicted using the phenotypic assay, but revealed only low levels of Ac re-insertion. Analyses of germinal transposition in the iae1 mutant demonstrated an average germinal excision frequency of 3% and a frequency of independent Ac re-insertions following germinal excision of 22%. The iae mutants represents a possible means of improving the efficiency of Ac/Ds transposon tagging systems in Arabidopsis, and will enable the dissection of host involvement in Ac transposition and the mechanisms employed for controlling transposable element activity

  19. Concurrent Electroencephalography Recording During Transcranial Alternating Current Stimulation (tACS).

    Fehér, Kristoffer D; Morishima, Yosuke

    2016-01-01

    Oscillatory brain activities are considered to reflect the basis of rhythmic changes in transmission efficacy across brain networks and are assumed to integrate cognitive neural processes. Transcranial alternating current stimulation (tACS) holds the promise to elucidate the causal link between specific frequencies of oscillatory brain activity and cognitive processes. Simultaneous electroencephalography (EEG) recording during tACS would offer an opportunity to directly explore immediate neurophysiological effects of tACS. However, it is not trivial to measure EEG signals during tACS, as tACS creates a huge artifact in EEG data. Here we explain how to set up concurrent tACS-EEG experiments. Two necessary considerations for successful EEG recording while applying tACS are highlighted. First, bridging of the tACS and EEG electrodes via leaking EEG gel immediately saturates the EEG amplifier. To avoid bridging via gel, the viscosity of the EEG gel is the most important parameter. The EEG gel must be viscous to avoid bridging, but at the same time sufficiently fluid to create contact between the tACS electrode and the scalp. Second, due to the large amplitude of the tACS artifact, it is important to consider using an EEG system with a high resolution analog-to-digital (A/D) converter. In particular, the magnitude of the tACS artifact can exceed 100 mV at the vicinity of a stimulation electrode when 1 mA tACS is applied. The resolution of the A/D converter is of importance to measure good quality EEG data from the vicinity of the stimulation site. By following these guidelines for the procedures and technical considerations, successful concurrent EEG recording during tACS will be realized. PMID:26862814

  20. Automatic Voltage Control (AVC) of Danish Transmission System - Concept design

    Qin, Nan; Abildgaard, Hans; Lund, P.;

    2014-01-01

    the buses are monitored where the voltage magnitudes are maintained continually. The loss minimization including switching cost is the objectives of the AVC system. The reactive power reserves as constraints are taken into account to limit the regulation capabilities of generators. The Day ahead and short......-term forecast is to be implemented to reduce the working load of the real time system, as well as to minimize the numbers of switching times of the discrete components. The fallback controllers are to be installed in selected substations to enhance the system reliability and the robustness in case...

  1. Bio-Authentication based Secure Transmission System using Steganography

    Zehra, Najme; Ahuja, Somya; Bansal, Shubha

    2010-01-01

    Biometrics deals with identity verification of an individual by using certain physiological or behavioral features associated with a person. Biometric identification systems using fingerprints patterns are called AFIS (Automatic Fingerprint Identification System). In this paper a composite method for Fingerprint recognition is considered using a combination of Fast Fourier Transform (FFT) and Sobel Filters for improvement of a poor quality fingerprint image. Steganography hides messages inside other messages in such a way that an "adversary" would not even know a secret message were present. The objective of our paper is to make a bio-secure system. In this paper bio-authentication has been implemented in terms of finger print recognition and the second part of the paper is an interactive steganographic system hides the user's data by two options- creating a songs list or hiding the data in an image.

  2. Optimal Allocation of Wind Turbines by Considering Transmission Security Constraints and Power System Stability

    Rodrigo Palma-Behnke; Claudia Rahmann

    2013-01-01

    A novel optimization methodology consisting of finding the near optimal location of wind turbines (WTs) on a planned transmission network in a secure and cost-effective way is presented on this paper. While minimizing the investment costs of WTs, the algorithm allocates the turbines so that a desired wind power energy-penetration level is reached. The optimization considers both transmission security and power system stability constraints. The results of the optimization provide regulators wi...

  3. Frequency Transmission Control of Local Networked Control Systems Approach

    O. Esquivel-Flores; H. Benítez-Pérez

    2012-01-01

    The use of Network Control Systems has been successful in the industry and therefore has opened several lines ofresearch. Control systems over a communication network include two important considerations, control andscheduling. Co-design strategies are focused on maintaining adequate control performance and maximize the level ofservice. Network scheduling is the main objective to resolve because through a balanced data load is possible tomaintain control performance in a desired level. This a...

  4. Data transmission system with encryption by chaotic sequences

    Politans’kyy R. L.; Shpatar P. M.; Hres A. V.; Verigha A. D.

    2014-01-01

    Protection of transferable information in the telecommunication systems is possible by its imposition of coding sequence on a plaintext. Encryption of pseudorandom sequences can be performed by using generation algorithms which are implemented on the basis of the phenomenon of dynamical chaos, which is sensitive to changes in the initial conditions. One of the major problems encountered in the construction of secure communication systems is to provide synchronization between the receiving and...

  5. The effect of DC superimposed AC Voltage on Partial Discharges in Dielectric Bounded Cavities

    Olsen, Pål Keim; Mauseth, Frank; Ildstad, Erling

    2014-01-01

    Voltage source converters is used in HVDC stations in offshore HVDC transmission systems, between the AC and DC power grid. The AC ripple voltage on the DC side of the HVDC stations can be in the range of 1-10 % of the nominal DC voltage, depending on the size of the filter employed. For offshore HVDC grids, there is a drive to use polymeric insulated cables on the DC side. This work investigates how an AC voltage at power frequency superimposed on DC voltage influence the partial discharge m...

  6. Predictive Current Control of a 7-level AC-DC back-to-back Converter for Universal and Flexible Power Management System

    Bifaretti, Steffano; Zanchetta, Pericle; Iov, Florin;

    2008-01-01

    The paper proposes a novel power conversion system for Universal and Flexible Power Management (UNIFLEX-PM) in Future Electricity Network. Its structure is based on a back-to-back three-phase AC-DC 7-level converter; each AC side is connected to a different PCC, representing the main grid and/or ...... numerous network conditions such as voltage unbalance, frequency excursions and harmonic distortion....

  7. Analytical investigation of the pericyclic variable-speed transmission system for helicopter main-gearbox

    Saribay, Zihni Burcay

    In the recent years, there has been significant interest in the new developments and improvements of the rotorcraft transmission systems. The main goal of the rotorcraft transmission research is the reduction of overall gear train weight while maintaining the efficiency and reliability. The Pericyclic Variable-Speed Transmission (PVT) System is one of the potential candidates of the future rotorcraft drive trains to achieve these goals. Hence, this thesis explores the feasibility of the Pericyclic Variable Speed Transmission (PVT) for rotorcraft transmissions. The contributions of this research are grouped in two main categories. These two categories are in the component level and in the system level. These contributions are originated from the analysis of the Pericyclic Variable Speed (PVT) System. In the component level, a new concept of face-gear meshing is presented first time in the gear research field. The meshing of a face-gear with another face-gear is presented at high shaft angles as an alternative to bevel gears. The conjugacy of this new face-gear meshing concept is formulated and demonstrated. The geometry, unloaded mesh kinematics and loaded mesh kinematics of the conjugate meshing face-gear pair is analyzed. The physics behind the meshing face-gear teeth contact is revealed using theory of gearing, differentiable geometry and elastohydrodynamic lubrication theory. The existence of the lubricant film formation between the meshing teeth is demonstrated. The behavior of the sliding friction coefficient is analytically simulated through the meshing cycle. In the system level contributions, the Pericyclic Variable Speed (PVT) Transmission is presented as a new unique innovative gear train mechanism. The speed change capability is analyzed for rotorcraft demands. The power flow behavior is explored for its use in variable speed transmission systems. The established component level contributions are evaluated with the PVT at the system level. The efficiency

  8. Progress on advanced dc and ac induction drives for electric vehicles

    Schwartz, H. J.

    1982-01-01

    Progress is reported in the development of complete electric vehicle propulsion systems, and the results of tests on the Road Load Simulator of two such systems representative of advanced dc and ac drive technology are presented. One is the system used in the DOE's ETV-1 integrated test vehicle which consists of a shunt wound dc traction motor under microprocessor control using a transistorized controller. The motor drives the vehicle through a fixed ratio transmission. The second system uses an ac induction motor controlled by transistorized pulse width modulated inverter which drives through a two speed automatically shifted transmission. The inverter and transmission both operate under the control of a microprocessor. The characteristics of these systems are also compared with the propulsion system technology available in vehicles being manufactured at the inception of the DOE program and with an advanced, highly integrated propulsion system upon which technology development was recently initiated.

  9. Force wave transmission through the human locomotor system.

    Voloshin, A; Wosk, J; Brull, M

    1981-02-01

    A method to measure the capability of the human shock absorber system to attenuate input dynamic loading during the gait is presented. The experiments were carried out with two groups: healthy subjects and subjects with various pathological conditions. The results of the experiments show a considerable difference in the capability of each group's shock absorbers to attenuate force transmitted through the locomotor system. Comparison shows that healthy subjects definitely possess a more efficient shock-absorbing capacity than do those subjects with joint disorders. Presented results show that degenerative changes in joints reduce their shock absorbing capacity, which leads to overloading of the next shock absorber in the locomotor system. So, the development of osteoarthritis may be expected to result from overloading of a shock absorber's functional capacity. PMID:7253613

  10. Experiments on Corona Discharge Under AC and DC Composite Voltage

    ZHU Zhengyi; LI Ruihai; WANG Guoli; CHEN Can; JIA Zhidong; GUAN Zhicheng

    2012-01-01

    Converter transformers are one of the most important electrical apparatuses in the ultra high voltage(UHV) DC transmission systems.The valve side and the low voltage(LV) bushing are stressed by long-term AC and DC composite voltage leading to significant partial discharge(PD) and posing great danger to the insulation system.In this paper AC and DC composite voltage is applied on a metal needle-plate model to produce PD signal sequences,and then the pulse waveshape and frequency spectrum are analyzed and compared with PD signals under conventional AC or DC voltage.In the end,the phase-resolved distribution is analyzed to depict the new characteristics of PD under this composite voltage.

  11. AC/DC Power Conversion System Using 3/9 Multiphase Transformer

    Ahmad Hoteit

    2012-07-01

    Full Text Available The main idea of this paper is to build a 3/9 AC multiphase transformer for conversion into DC power through the rectifier circuit which contains 18 pulse rectification with a ripple factor less than 0.8% produced by the odd phase number 9. This modeling has been simulated using Orcad simulation software, the nine phases are out of the main three phase power lines, each phase is shifted from the other by 40o (360o/9, this type of transformer is often required in aerospace, railway and automobile applications.

  12. An 225Ac/213Bi generator system for therapeutic clinical applications: construction and operation

    A method for construction and operation of an 225Ac/213Bi generator capable of producing 25-100 mCi of 213Bi suitable for clinical antibody labeling is described. The generator has been designed to have an effective lifetime of several weeks, producing up to six therapeutic doses of radionuclide per day. To date, 57 clinical doses have been prepared and injected into patients using the described 213Bi generator. Factors such as radiation damage, radioprotection, iodide eluate chemistry, radiolabeling chemistry and radionuclidic purity are addressed

  13. Transmission Modulated by Quantum Gate in Aharonov-Casher Ring

    1999-01-01

    We study the electron transmission tuned by quantum gate in an Aharonov-Casher (AC) ring. Transmis-sion probability is obtained as a function of the normalized textured electric fields and Fermi energy. We find thatmodulating electron wavefunction in the stub can drastically affects electron transmission through the ring system.As Fermi energy crosses every eigenenergy of the isolated stub, the phases of both anomalous and periodic oscillationsof the AC conductance generally have abrupt change by π. On two sides of several special Fermi energies, bothanomalous and periodic oscillations have no abrupt phase change and are in phase. The detailed characteristics of theanomalous oscillations are dependent on the difference between the tilt angle of the spin and that of textured electricfield. By modulating external magnetic field applied to the stub, we present AC oscillations of spin-polarized conduc-tance within adiabatic limit.

  14. System of automatic control over data Acquisition and Transmission to IGR NNC RK Data Center

    Automated system for seismic and acoustic data acquisition and transmission in real time was established in Data Center IGR NNC RK, which functions very successively. The system monitors quality and volume of acquired information and also controls the status of the system and communication channels. Statistical data on system operation are accumulated in created database. Information on system status is reflected on the Center Web page. (author)

  15. Impact of Utility-Scale Distributed Wind on Transmission-Level System Operations

    Brancucci Martinez-Anido, C.; Hodge, B. M.

    2014-09-01

    This report presents a new renewable integration study that aims to assess the potential for adding distributed wind to the current power system with minimal or no upgrades to the distribution or transmission electricity systems. It investigates the impacts of integrating large amounts of utility-scale distributed wind power on bulk system operations by performing a case study on the power system of the Independent System Operator-New England (ISO-NE).

  16. Distance Protection of Cross-Bonded Transmission Cable-Systems

    Bak, Claus Leth; F. Jensen, Christian

    2014-01-01

    systems are being laid around the world. Differential protection is often used for the main protection of cables. As a backup protection, distance protection is very often the preferred choice. Therefore, the behaviour of distance protection when applied to cross-bonded cablesystems is very interesting....

  17. The hardware-in-the-loop simulation test of a parallel hybrid transmission control system

    Marco, J. [Pi Technology, Cambridge (United Kingdom); Ball, R. [University of Warwick, Coventry (United Kingdom). Warwick Manufacturing Group; Jones, R.P. [University of Warwick, Coventry (United Kingdom). School of Engineering; Roxburgh, A. [Warwick Control Technologies, Coventry (United Kingdom)

    2001-07-01

    This paper will present the hardware-in-the-loop simulation test of the transmission control system for the HERO (Hybrid Electric Realised Off-road) vehicle. HERO is a parallel hybrid derivative of a Land Rover Defender. The powertrain consists of a diesel engine and an electrical machine mechanically coupled to the gearbox input shaft. The main function of the transmission control system is to employ the electrical machine to actively assist in gear changes. The transmission control system is a combination of feedback compensation elements and supervisory rule-bases. The simulated performance of the control system is compared to the results obtained when the control algorithms have been converted to a source code program and compiled to the control module operating within a HILST environment. (author)

  18. Transmission Congestion and Voltage Profile Management Using TCSC and TCPAR in Deregulated Power System

    K.Ragini

    2014-10-01

    Full Text Available In present days all our basic needs are relates with electricity. As the population increases, the demand for electricity is also tremendously increases. In the past, the entire electricity industry is under the control of government and also monopolized. But now, the power industry in many countries is moving rapidly from regulated conventional setup to deregulated environment. The transmission congestion is one of the technical problems that particularly appear in the deregulated power system. If congestion is not managed we face the problems of electricity price improvement and security and stability problems. Congestion relief can be handled using FACTS device such as TCSC, TCPAR where transmission capability will be improved. These FACTS devices are optimally placed on transmission system using Sensitivity approach method. The proposed method is carried out on Modified IEEE-14 bus system and IEEE-24 bus system Using Power World Simulator17 software.

  19. Theoretical and experimental comparison of an ultra-high-speed laser data transmission system

    Tycz, M.

    1973-01-01

    The performance of a digital optical data transmission system is specified by the probability that the system erroneously decides a signal has or has not been transmitted. Two factors which induce signal fading and thereby decrease system performance are atmospheric scintillation and transmitter pointing inaccuracy. A channel simulator was developed that is capable of producing the effects of both atmospheric scintillation and the transmitter pointing problem for a neodymium-yag optical data transmission systems. Comparison of data taken from the modulated intensity of a beam having been transmitted through the channel simulator with experimental data from GEOS-B argon laser transmission through the atmosphere to a low earth-orbiting satellite indicates that the modulated signal intensity is log-normal to the degree of measured atmospheric scintillation.

  20. The Effects of Crack on the Transmission Matrix of Rotor Systems

    Z.K. Peng

    2011-01-01

    Full Text Available The dynamic behavior of rotor containing crack is a subject of particular interest and has been extensively investigated by researchers. The effects of crack on the natural frequencies and modal shapes and motion orbits of rotor systems have already been well explored by researchers. In the present study, the infl uence of crack on the transmission matrices of the rotor systems is investigated by using the FEM (finite element method analysis and the HBM (harmonic balance method technique. It is for the first time revealed that there are differences between the transmission matrices for the fundamental frequency components and the transmission matrices for the super-harmonic components, and the differences are mainly determined by the crack location. The results are validated by numerical experiments where the system responses of a rotor system are obtained using Runge-Kutta method. The results are of significance for the development of effective crack detection methods in practice.

  1. The Numerical Analysis of Transmission Tower-Line System Wind-Induced Collapsed Performance

    Zhuoqun Zhang

    2013-01-01

    Full Text Available The numerical simulation of transmission tower-line systems' progressive collapse performance is considered as a major research hotspot and significant project, due to the increasing number of wind-induced collapse accidents recently. In this study, the finite element models for single tower and transmission tower-line system were established to simulate wind-induced progressive collapse by birth-to-death element technique in ABAQUS/Explicit. The wind field, based on the Kaimal fluctuating wind power spectrum and harmonic superposition method, was constructed by MATLAB commercial software. The current research focuses on the dynamic behaviour and the mechanism of a typical transmission tower-line system progressive collapse under wind action with clear step-by-step description. The numerical simulation results demonstrated that transmission tower-line system collapse mechanism depended on the number, position and last deformation of damage elements. Since the gallop effect of conductor and ground lines were ignored in the single tower model, the transmission tower-line system model, which has higher computational precision than the single tower model, is relatively accurate and recommended strongly in the design.

  2. Report on Nova Scotia Power Company's transmission system and outages communications

    Stright, R.; Cannata, M.D.Jr.; Lautenschlager, M.; Kozlosky, C.K.; Arndt, S.M. [Liberty Consulting Group, Quentin, PA (United States)

    2005-03-04

    A severe storm occurred in Nova Scotia on November 13 and 14, 2004, during which a large portion of Nova Scotia Power Inc. (NSPI) customers were without power. The storm severely damaged sections of Nova Scotia's power transmission and distribution systems. The Nova Scotia Utility and Review Board issued a request for proposals (RFP) for consultants to examine NSPI's communications as well as its transmission system operations, maintenance and planning. The Liberty Consulting Group conducted the study and reported on transmission system maintenance and structure design; transmission system planning and system design; and communications and outage response. The consultant field inspected the adequacy of design criteria and the condition of failed and remaining towers and poles in areas affected by the storm and compared results with areas not affected by the storm. The consultant also evaluated NSPI's maintenance and inspection programs, vegetation management, staffing, replacement structure inventory and lessons learned from previous weather events. The report revealed how the collapse of a small number of transmission towers resulted in such a major outage. Following the review, 74 actions were created, of which more than half are complete. tabs, figs.

  3. Development of Wireless Data Transmission System for the Monitoring in Geological Disposal of Radioactive Waste - 12063

    The authors have been developing a wireless data transmission system to monitor the performance of a geological disposal system for radioactive waste. The system's concepts, advantages, and a recent development focused on reducing transmitter size to suit narrow spaces such as bentonite buffers and boreholes. A wireless transmitter with a built-in temperature sensor and a connector for external sensors has been developed, measuring 130 mm in length and 50 mm in diameter. The capability of the transmitter was confirmed by transmission tests on the ground and in a bentonite block. (authors)

  4. Asynchronous Message Transmission Technique for Latency Requirements in Time Critical Ship-borne System

    N. P. Shrivastava

    2016-01-01

    Full Text Available A solution to data ageing requirements in time critical ship system like fire control system is presented. In an operational sea borne platform, navigation requirements for the onboard systems are fulfilled by ring laser gyro-based inertial navigation system. For critical systems like fire control system, navigational data must be delivered in real time without any delay. However due to delay occurring in processing of raw information and transmission of data on interface bus some latency is introduced. Algorithm for an asynchronous message transmission technique from inertial navigation system to user system to meet its latency requirements is discussed. Latency requirement is achieved by sending a separate message with the time stamp for the instance the first byte of 100 Hz attitude data is received at the processing computer of navigation system.Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 26-29, DOI: http://dx.doi.org/10.14429/dsj.66.8502

  5. Game Changing Usage of High-Voltage Power Transmission Systems as Extremely Large Antennas for Space Physical and Geophysical Remote Imaging Project

    National Aeronautics and Space Administration — Geomagnetic storms drive geomagnetically induced currents (GIC) in high-voltage power transmission systems worldwide. GIC distribution in the transmission system is...

  6. Frequency Transmission Control of Local Networked Control Systems Approach

    O. Esquivel-Flores

    2012-08-01

    Full Text Available The use of Network Control Systems has been successful in the industry and therefore has opened several lines ofresearch. Control systems over a communication network include two important considerations, control andscheduling. Co-design strategies are focused on maintaining adequate control performance and maximize the level ofservice. Network scheduling is the main objective to resolve because through a balanced data load is possible tomaintain control performance in a desired level. This article reviews a scheduling strategy based on frequencytransition modeled as a linear subsystem, this control reconfigure on line the sensors’ periods. The case of study isthe control of a prototype helicopter and by numerical simulations it shows the effect of changing the transmissionfrequency.

  7. Radio Transmission Performance of EPCglobal Gen-2 RFID System

    Mohaisen, Manar; Chang, KyungHi

    2009-01-01

    In this paper, we analyze the performance of the encoding and the modulation processes in the downlink and uplink of the EPCglobal Gen2 system through the analysis and simulation. Furthermore, the synchronization issues on time and frequency domain and the preamble architecture are evaluated. Through the simulation in the uplink, we find that the detection probability of FM0 and Miller coding approaches 1 at 13dB Eb/N0.

  8. Compensating for Nonlinear Effects in Coherent Detection Optical Transmission Systems

    2012-01-01

    Fiber nonlinearity is one of the most important limiters of capacity in coherent optical communications. In this paper, we review two nonlinear compensation methods: digital backward propagation (BP) and nonlinear electrical equalizer (NLEE) based on the timedomain Volterra series. These compensation algorithms are implemented in a singlechannel 50 Gb/s coherent optical singlecarrier frequency division multiplexed (CO-SCFDM) system transmitting over 10 × 80 km of standard singlemode fiber (SSMF).

  9. Nonreciprocal transmission of neutrons through the noncoplanar magnetic system

    Tatarskiy, D. A.; Petrenko, A. V.; S. N. VDOVICHEV; Udalov, O. G.; Nikitenko, Yu. V.; Fraerman, A. A.

    2014-01-01

    We report on observation of the time reversal symmetry breaking in unpolarized neutrons scattering experiment. Neutron transmittivity through the system consisting of two magnetic mirrors placed in an external magnetic field is measured. Time reversal symmetry holds for coplanar magnetic configuration, meaning that transmitted intensity does not change when interchanging neutron source and detector. Contrarily, for noncoplanar magnetic configuration the time reversal symmetry breaks down. In ...

  10. Digital signal transmission with cascaded heterogeneous chaotic systems

    Murali, K.

    2001-01-01

    A new chaos based secure communication scheme is proposed to transmit digital signals by combining the concepts of chaotic-switching and chaotic-modulation approaches. In this scheme two heterogeneous chaotic circuits are used both at the transmitter and receiver modules. First a binary message signal is scrambled by two chaotic attractors produced by a set of chaotic systems (No. 1) of the drive module. The so produced small amplitude scrambled chaotic signal is further directly injected or modulated by different chaotic system (No. 2) within the drive module. Then the chaotic signal generated by this second chaotic system No. 2 is transmitted to the response module through the channel. An appropriate feedback loop is constructed in the response module to achieve synchronization among the variables of the drive and response modules and the binary information signal is recovered by using the synchronization error followed by low-pass filtering and thresholding. Simulation results are reported in which the quality of the recovered signal is higher and the encoding of the information signal is potentially secure. The effect of perturbing factors like channel noise and nonidentity of parameters are also considered.

  11. A.c. susceptibility study of CaCl2 doped copper–zinc ferrite system

    A Y Lipare; P N Vasambekar; A S Vaingankar

    2003-08-01

    Polycrystalline soft ferrites, Zn$_x$ Cu$_{1–x}$ Fe2O4 ( = 0.30, 0.50, 0.70, 0.80 and 0.90), doped with controlled amount of calcium chloride (CaCl2) were prepared by standard ceramic route and studied for a.c. susceptibility. X-ray diffraction studies of the compositions reveal formation of single-phase cubic spinel. The values of lattice constant increase as doping percentage of CaCl2 increased from 0.01% to 0.05% and afterwards decrease slightly. The presence of chlorine ions is confirmed by absorption peak in far IR spectra near 650 cm-1 for all the samples. The variation of a.c. susceptibility with temperature shows the existence of single domain structure for = 0.3 and exhibits transition from single domain to multidomain structure with increased Ca2+ contents from 0.01 to 0.1%. The composition, = 0.5, shows multidomain structure independent of Ca2+ content. The samples for = 0.70, 0.80 and 0.90 show paramagnetic behaviour at and above room temperature.

  12. AC drive system with 4 in-wheel motor for high performance electric vehicle. Yonrin Kudo koseino denki jidoshayo AC drive system

    Terashima, M.; Ashikaga, T.; Mizuno, T. (Meidensha Corp., Tokyo (Japan)); Yamamoto, T.; Natori, K.; Fujiwara, N. (The Tokyo Electric Power Co. Inc., Tokyo (Japan))

    1994-01-20

    This paper describes the following matters on a driving motor and its control system used in the electric vehicle, IZA, that has achieved performance comparable to that of gasoline-fueled cars: a system has been employed that synchronous motors using rare earth magnets as the magnetic field are assembled into each of the four wheels to drive them directly. Taking into consideration that a maximum torque of about eight times that of the rating would be required, discussions have been given on effects of the magnetic saturation in the field, and a selection has been made on a magnet shape that can reduce torque pulsation of the motor. An incident of current uncontrollability caused by induction voltage in the motor during high rotation speeds has been avoided by demagnetization control to have achieved a speed of 176 km/h. The control system has been structured based on the control methods that consider the battery characteristics, inverter loss, and motor loss, realizing a torque control over a wide range. The motors, the inverters, and the drive system have been verified to have near design performance according to evaluation tests. 12 refs., 13 figs., 2 tabs.

  13. Development of an elastic-impulse power transmission for wind energy conversion systems

    Pahl, B.

    1986-01-01

    A multiload-capable elastic-impulse power transmission for use in Wind Energy Conversion Systems (WECS) was designed, prototype constructed and bench tested. The transmission interposes a temporary energy storage device between the input and output shafts, and therefore allows the two shafts to rotate at virtually independent speeds. For utility interface induction generators which must run at essentially constant speed, the transmission allows the turbine rotor to run at variable speed, thereby maintaining the constant tip-speed ratio corresponding to the peak-power point. The transmission was found to work in principle, but the first construction prototype exhibited low efficiencies (24%) due to the constraints imposed by the utilization of commercial components.

  14. Underground transmission system with special connections; Sistema de transmissao subterranea com conexoes especiais

    Nishimura, Fumitaka [ALCOA Aluminio S.A. (Brazil); Dias, Eduardo M. [Sao Paulo Univ., SP (Brazil). Escola Politecnica; Samico, Roberto A.M.; Hinds, Armando B. [Light Servicos de Eletricidade SA (Brazil)

    1991-12-31

    This work describes the functioning of the electric power underground transmission systems with metallic insulation connected in `cross-bonding`. To the correct sizing of such system a computational program was developed. A study case is presented 4 refs., 6 figs., 5 tabs.

  15. Insulator and Clerance Requirements in Overhead Line Transmission Systems without Shield Wires

    Sørensen, Thomas Kjærsgaard; Holbøll, Joachim

    2008-01-01

    This paper theoretically examines the required insulation lengths and clearances in 400 kV overhead line systems when not making use of ground wires as lightning protection. The influence of lightning strikes to the system is investigated based on dynamic transmission line simulations of a 400 k...

  16. Probe Improvement of Inductive Sensor for Online Health Monitoring of Mechanical Transmission Systems

    Wang, Chao; Liu, Xiao; Chen, Zhe

    2015-01-01

    Metal debris in lubricating oil contains abundant information regarding the ageing and wear/damage of mechanical transmission systems. The health condition of the lubricated systems can be indicated by the concentration and size of the metal abrasive particles, which may provide very early warnings...

  17. A new inductive sensor for online health monitoring of mechanical transmission systems

    Wang, Chao; Liu, Xiao; Chen, Zhe

    2015-01-01

    Metal debris in lubricating oil contains abundant information regarding the ageing and wear of mechanical transmission systems. The health condition of the lubricated systems can be indicated by the quantity and size of the metal particles, which may provide very early warnings of faults/ failures...

  18. Experimental security estimation of multimedia digital data transmission systems based on SHDSL technologies

    Shynkarenko, I.V.; Tsopa, O. I.

    2011-01-01

    The paper presents a structure of the hardware-software complex for investigating the wiretap channels of wire segments of local communication systems. In addition, it also presents new experimental data on the estimation of hiding and noise immunity of multimedia digital data transmission systems based on SHDSL technologies.

  19. Design of data transmission system for high-energy X-ray industrial CT

    Aiming at the characteristics of high-energy X-ray industrial computerized tomography(CT), a data transmission system based on USB2.0 was developed. The system consists of a USB2.0 interface and a transmission control unit. The USB2.0 interface unit uses Cypress's EZ-USB FX2-CY7CS8013A chip, which is set as the slave FIFO interface model to transfer data to host computer by bulk transfer mode. The transmission control unit uses Altera's Cyclone-EP1CSQ240C8N chip which defines buffer to receive the data from detecting part, generate logic control signals and timing sequence signals, and send the data to the endpoint buffer of USB. The data transmission system was tested well and can meet the requirements of high-energy X-ray indus, trial CT. Also it can expand easily and take up a few system resources with high transmission rate. (authors)

  20. Capacitor placement for transmission systems using ordinal optimization approach

    Lin, S.-Y. [National Chiao Tung Univ., Hsinchu, Taiwan (China); Lin, C.-H. [Kao-Yuan Univ. Technology, Kaohsiung, Taiwan (China)

    2007-07-01

    Capacitor placement poses a challenge in power system design because it involves integer variables for determining the placement locations and discrete variables for deciding the number of capacitor banks to be installed. It is also a large-dimension constrained optimization problem for considering the system constraints and, investment constraint. This paper proposed an ordinal optimization (OO) approach for solving this problem. The approach consisted of five OO iterations. The size and solution quality of the resulting candidate solution set was reduced and improved, iteration by iteration. A reasonable capacitor placement pattern was obtained in the final iteration. In addition, in order to demonstrate the computational efficiency of the approach and the quality of the obtained solutions, the genetic algorithm was compared with the TABU search method. The paper defined the problem statement and discussed the OO approach and explained the five iterations and theory. The test results demonstrated that the proposed approach is suitable for the capacitor placement problem. 16 refs., 2 tabs.

  1. Information and data real time transmission acoustic underwater system: TRIDENT

    Trubuil, Joel; Labat, Joel; Lapierre, Gerard

    2001-05-01

    The objective of the Groupe d'Etudes Sous-Marines de l'Atlantique (GESMA) is to develop a robust high data rate acoustic link. A real-time receiver recently developed at ENST Bretagne has just been designed to cope with all perturbations induced by such harsh channels. In order to cope with channel features, a spatio-temporal equalizer introduced by J. Labat et al. [Brevet FT no. 9914844, ``Perfectionnements aux dispositifs d'galisation adaptative pour recepteurs de systemes de communications numriques,'' Nov. 1999] was recently implemented and evaluated. This equalizer is the core of the receiver platform [Trubuil et al., ``Real-time high data rate acoustic link based on spatio temporal blind equalization: the TRIDENT acoustic system,'' OCEANS 2002]. This paper provides an overview of this project. The context of the study and the design of high data rate acoustic link are presented. Last Brest harbor experiments (2002, 2003) are described. The real time horizontal acoustic link performances are evaluated. Two carriers frequencies are available (20, 35 kHz). Acoustic communications for bit rate ranging from 10 to 20 kbps and for channel length (shallow water) ranging from 500 to 4000 m have been conducted successfully over several hours.

  2. Performance evaluation of analog signal transmission in an orbital angular momentum multiplexing system.

    Li, Shuhui; Wang, Jian

    2015-03-01

    We propose and experimentally demonstrate analog signal transmission in an orbital angular momentum (OAM) multiplexing system. By employing two spatial light modulators (SLMs), each loaded with a complex phase pattern generating 4 OAM beams, an 8 OAM multiplexing system is established for analog signal transmissions. The crosstalk between each OAM channel is measured to assess the performance of the OAM multiplexing system. Using 3-GHz analog signals over 8 OAM beams, we evaluate the performance of OAM multiplexing analog signal transmissions. The spurious free dynamic range (SFDR) of the second-order-harmonic distortion (SHD) and the third-order-harmonic distortion (THD) are measured and characterized for each OAM channel. PMID:25723426

  3. A Case Study Of Turkish Transmission System For VoltageDips

    Inan, E.; Alboyaci, B.; Bak, Claus Leth

    2009-01-01

    Power quality problems usually appear in the form of voltage sags, transients and harmonics. From these three broad categories of power quality problems, voltage dips account the most disturbances experienced by industrial customers. Voltage dips generally refer to instantaneous short-duration vo...... analysis of voltage dip performance of the whole transmission system, is used to compare with results constructed fault statics from SIMPOW DIPS analysis program real data. SIMPOW DIPS software enables to calculate dip frequency for all busses and lines.......-duration voltage variations. The aim of this paper is to have an idea about voltage dip performance of Turkey Transmission System. Turkey's transmission system has 21 regions. For simulations, 2nd region, which includes Istanbul city's area is heavy loaded, is selected. For purposes of early warning and later...

  4. Reliability worth applied to transmission expansion planning based on ant colony system

    Leite da Silva, Armando M.; Rezende, Leandro S. [Institute of Electric Systems and Energy, Federal University of Itajuba, UNIFEI (Brazil); da Fonseca Manso, Luiz A.; de Resende, Leonidas C. [Department of Electrical Engineering, Federal University of Sao Joao del Rei, UFSJ (Brazil)

    2010-12-15

    This paper proposes a new methodology to solve transmission expansion planning (TEP) problems in power system, based on the metaheuristic ant colony optimisation (ACO). The TEP problem includes the search for the least cost solution, bearing in mind investment cost and reliability worth. Reliability worth is considered through the assessment of the interruption costs represented by the index LOLC - loss of load cost. The focus of this work is the development of a tool for the multi-stage planning of transmission systems and how reliability aspects can influence on the decision-making process. The applications of the proposed methodology are illustrated through case studies carried out using a test system and a real sub-transmission network. (author)

  5. Interior point algorithm-based power flow optimisation of a combined AC and DC multi-terminal grid

    Farhan Beg

    2015-01-01

    Full Text Available The high cost of power electronic equipment, lower reliability and poor power handling capacity of the semiconductor devices had stalled the deployment of systems based on DC (multi-terminal direct current system (MTDC networks. The introduction of voltage source converters (VSCs for transmission has renewed the interest in the development of large interconnected grids based on both alternate current (AC and DC transmission networks. Such a grid platform also realises the added advantage of integrating the renewable energy sources into the grid. Thus a grid based on DC MTDC network is a possible solution to improve energy security and check the increasing supply demand gap. An optimal power solution for combined AC and DC grids obtained by the solution of the interior point algorithm is proposed in this study. Multi-terminal HVDC grids lie at the heart of various suggested transmission capacity increases. A significant difference is observed when MTDC grids are solved for power flows in place of conventional AC grids. This study deals with the power flow problem of a combined MTDC and an AC grid. The AC side is modelled with the full power flow equations and the VSCs are modelled using a connecting line, two generators and an AC node. The VSC and the DC losses are also considered. The optimisation focuses on several different goals. Three different scenarios are presented in an arbitrary grid network with ten AC nodes and five converter stations.

  6. Stability analysis of transmission system with high penetration of distributed generation

    M.Reza

    2006-01-01

    Nowadays, interest in generating electricity using decentralized generators of relatively small scale ('distributed generation', DG) is increasing. This work deals with the impact of implementing DG on the transmission system transient stability, with the emphasis on a potential transition from a 'vertical power system' to a 'horizontal power system. A problem in power systems is maintaining synchronous operation of all (centralized) synchronous machines. This stability problem associated is ...

  7. Transmission of specific groups of bacteria through water distribution system.

    Grabińska-Łoniewska, Anna; Wardzyńska, Grazyna; Pajor, Elzbieta; Korsak, Dorota; Boryń, Krystyna

    2007-01-01

    Microbial contamination of a water distribution system was examined. The number and the taxonomy of non-pigmented and pigmented heterotrophic bacteria (HB), number of bacteria (Pseudomonas sp., Enterococcus sp., Campylobacter sp., Yersinia sp., representatives of the Enterobacteriaceae, coagulase-positive staphylococci, and C. pefringens) in the bulk water phase, biomass of zoogloeal aggregates of bacteria, fungi, algae, protozoa and rotifers (ZABFAPR) (separated from the above on 5 microm pore size filters) and in pipe sediments was determined. An increased number of HB occurred at the sampling sites situated as close as 4.2 km to the Water Treatment Plant (WTP), and was especially significant at 10.3 km. It was shown that the main reservoir of hygienically relevant bacteria did not occur in the water phase which is monitored in routine control analyses carried out by the WTP laboratories, but in the ZABFAPR biomass not monitored so far. PMID:17650683

  8. A Data Transmission Technique for Personal Health Systems

    Jih-Fu Tu

    2013-01-01

    Full Text Available We used the modular technique to design a personal health data transmitter (PHDT that is composed of the following components: (1 the core is an embedded signal chip, (2 three kinds of transmutation modules such as USB, RF, and UART, (3 an I2C interface is used to acquire the users data, and (4 through Internet it links to the cloud server to store the personal-health data. By the experiment, we find that the modular manner is feasible, stable of functional, integral, and accurate, while it is exploited to design the PHDT. For the experiment, we present each module algorithm to find that our system is very helpful to people.

  9. Power line maintenance information system using low-power radio data transmission. Shodenryoku musen denso wo riyoshita sodensen hoshu joho system

    Kanemaru, K.; Matsubara, R.; Kaito, J.; Toyota, S. (Hitachi Cable, Ltd., Tokyo (Japan))

    1994-05-20

    Currently in the major power transmission line, a composite fiber optic overhead ground wire (OPGW) is installed, and it is being made the best use as an information transmission line. When the various maintenance informations on the transmission lines can be collected and transmitted by utilizing this OPGW, there will be the benefits that an effective system for the maintenance work of the transmission lines can be constructed, the informations, which could not be obtained by a conventional patrol and tour inspection so far, could be all the time acquired highly accurately and more rapidly. In this report by considering a use of the radio transmission together with OPGW transmission, in order to solve the constraints on an information transmission in a power transmission line maintenance system by utilizing OPGW, the concrete radio transmission systems were proposed about each of interpolation method of the sensor signal transmission method and the OPGW data transmission system. Especially as for the sensor signal system, it was shown that, as a result of the quantitative investigation of a transmission efficiency taking account of the hidden terminal problems, an interpolating data transmission system through a low-power radio combined the slotted transmission timing with the carrier sensed multiple access (CSMA) system was superior. 8 refs., 7 figs., 6 tabs.

  10. Transient Stability of the Power System with the Exact Long Transmission Line Model

    Prechanon Kumkratug

    2012-01-01

    Full Text Available Problem statement: The exact long transmission line model consists of the lump of the series resistance, reactance and shunt capacitance. With the consideration the actual long transmission line model, it causes in the difficulty of deriving the mathematical model. Approach: This study investigates the transient stability of power system with consideration the exact long transmission line model. The concept of two-port network is applied in this study. The generator, transformer and short transmission line are represented by two-port networks. With the combination principles of the series and shunt connection, the mathematical model is achieved in a much simpler way. The proposed method is tested on the sample system and compared on various cases. Results: The first swing of rotor angle curve of the faulted system without the resistance is obviously higher than that of with the resistance whereas the second swing of the faulted system without the resistance is slightly less than that of with the resistance. The critical clearing time of the system with the resistance is better than that of with resistance. Conclusion: It was found from the simulation results that the resistance of the line provides the improvement of the first swing but not for the second swing. It was found from this study that for practical long line, the resistance is very import parameters to determine the critical clearing time of the single machine infinite system whereas shunt capacitance insignificantly affects on the critical clearing time of the single machine infinite bus system.

  11. GPS-Like Phasing Control of the Space Solar Power System Transmission Array

    Psiaki, Mark L.

    2003-01-01

    The problem of phasing of the Space Solar Power System's transmission array has been addressed by developing a GPS-like radio navigation system. The goal of this system is to provide power transmission phasing control for each node of the array that causes the power signals to add constructively at the ground reception station. The phasing control system operates in a distributed manner, which makes it practical to implement. A leader node and two radio navigation beacons are used to control the power transmission phasing of multiple follower nodes. The necessary one-way communications to the follower nodes are implemented using the RF beacon signals. The phasing control system uses differential carrier phase relative navigation/timing techniques. A special feature of the system is an integer ambiguity resolution procedure that periodically resolves carrier phase cycle count ambiguities via encoding of pseudo-random number codes on the power transmission signals. The system is capable of achieving phasing accuracies on the order of 3 mm down to 0.4 mm depending on whether the radio navigation beacons operate in the L or C bands.

  12. Application of ACS6000C Cycloconverter in the Hoist System of Coal Mine%ACS6000C交流调速技术在矿井提升系统的应用

    孟强; 廉鲁炜

    2013-01-01

    本文介绍一种全数字可编程模块化交流调速控制系统,ABB公司ACS6000C系统,其独特的应用和电机控制处理板(AMC3板),能进行高速动态信息处理以及对专门的控制系统进行调节和控制,在矿井提升机同步电机的调速控制应用中显现出高性能的响应和精确的力矩控制。实现了矿井提升机的安全、高效、稳定运行。%This paper introduces a digital programmable modular AC speed control system, ACS6000C system of ABB company, the applica-tion and motor unique control board (AMC3 board), can make high speed dynamic information processing and control and adjust the control system of the special, in the synchronous motor in mine hoist control showing response high performance and precise torque control applica-tions. The mine hoist safe, efficient and stable operation of machine.

  13. Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels

    Yilmaz, Ferkan

    2012-03-01

    In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.

  14. Emergency ac power systems operating experience at US nuclear power plants, 1976 through 1983

    Success and failure data of test and emergency starts of emergency ac power sources (diesel generators) at US nuclear power plants were collected and evaluated to estimate diesel generator reliability parameters. A regression analysis of the estimates of the probability of failure to start based on surveillance test data from 1976 through 1983 indicates that the probability of failure to start has been decreasing. However, the reliability of diesel generator performance during losses of off-site power for 1981 through 1983 was less than expected based on the test data estimates. The failures that occurred during losses of off-site power were reviewed to determine why the calculated failure to start was greater than expected, and possible explanations for this high value are presented. The subsystems involved in diesel generator subsystem failures were categorized to determine whether there were any dominant failure modes. The results indicate that further significant improvement in diesel generator reliability will require improvement of many subsystems

  15. Pressure control of a pneumatic control system with a long transmission line

    In this study, a robust controller to control pressure in a pneumatic pressure vessel with a long transmission line is proposed. Frequency response of transmission line using compressible fluid is changed by the flowing state of the fluid. So, if a fixed gain controller designed based on a model supposed the flowing state to a specific state, the performance of the control system could be degraded because of the modelling error. The controller designed in this study is composed of two parts. One is a feedback controller to improve a feedback characteristics and to compensate the influence of the variation of transfer characteristics of a transmission line owing to the change of flowing state and the other is a feed forward controller to regulate command following performance. The experimental results with the designed controller show that the robustness of the control system is achieved regardless of the change of the model of the transmission line. Therefore, the designed controller can be utilized for the performance improvement of a pressure control system with a long transmission line using compressible fluid

  16. Advanced Technology Application Station Blackout Core Damage Frequency Reduction - The Contribution of an AC Independent Core Residual Heat Removal System

    An event of station blackout (SBO) can result in severe core damage and undesirable consequences to the public and the environment. To cope with an SBO, nuclear reactors are provided with protection systems that automatically shut down the reactor, and with safety systems to remove the core residual heat. In order to reduce core damage frequency, the design of new reactors incorporates passive systems that rely only on natural forces to operate. This paper presents an evaluation of the SBO core damage frequency of a PWR reactor being designed in Brazil. The reactor has two core residual heat removal systems - an AC dependent system, and a passive system. Probabilistic safety assessment is applied to identify failure scenarios leading to SBO core damage. The SBO is treated as an initiating event, and fault trees are developed to model those systems required to operate in SBO conditions. Event trees are developed to assist in the evaluation of the possible combinations of success or failure of the systems required to cope with an SBO. The evaluation is performed using SAPHIRE, as the software for reliability and risk assessment. It is shown that a substantial reduction in the core damage frequency can be achieved by implementing the passive system proposed for the LABGENE reactor design. Keywords: Station blackout, passive safety system, core damage frequency. (author)

  17. Station Blackout Core Damage Frequency Reduction - The Contribution of an AC Independent Core Residual Heat Removal System

    An event of station blackout (SBO) can result in severe core damage and undesirable consequences to the public and the environment. To cope with an SBO, nuclear reactors are provided with protection systems that automatically shut down the reactor, and with safety systems to remove the core residual heat. In order to reduce core damage frequency, the design of new reactors incorporates passive systems that rely only on natural forces to operate. This paper presents an evaluation of the SBO core damage frequency of a PWR reactor being designed in Brazil. The reactor has two core residual heat removal systems - an AC dependent system, and a passive system. Probabilistic safety assessment is applied to identify failure scenarios leading to SBO core damage. The SBO is treated as an initiating event, and fault trees are developed to model those systems required to operate in SBO conditions. Event trees are developed to assist in the evaluation of the possible combinations of success or failure of the systems required to cope with an SBO. The evaluation is performed using SAPHIRE, as the software for reliability and risk assessment. It is shown that a substantial reduction in the core damage frequency can be achieved by implementing the passive system proposed for the LABGENE reactor design. Keywords: Station blackout, passive safety system, core damage frequency. (author)

  18. Momentum-independent reflectionless transmission in the non-Hermitian time-reversal symmetric system

    Zhang, X.Z.; Song, Z., E-mail: nkquantum@gmail.com

    2013-12-15

    We theoretically study the non-Hermitian systems, the non-Hermiticity of which arises from the unequal hopping amplitude (UHA) dimers. The distinguishing features of these models are that they have full real spectra if all of the eigenvectors are time-reversal (T) symmetric rather than parity-time-reversal (PT) symmetric, and that their Hermitian counterparts are shown to be an experimentally accessible system, which have the same topological structures as that of the original ones but modulated hopping amplitudes within the unbroken region. Under the reflectionless transmission condition, the scattering behavior of momentum-independent reflectionless transmission (RT) can be achieved in the concerned non-Hermitian system. This peculiar feature indicates that, for a certain class of non-Hermitian systems with a balanced combination of the RT dimers, the defects can appear fully invisible to an outside observer. -- Highlights: •We investigate the non-Hermitian system with time reversal symmetry. •The Hermitian counterpart is experimentally accessible system. •The behavior of momentum-independent reflectionless transmission can be achieved. •A balanced combination of reflectionless transmission dimers leads to invisibility. •It paves an alternative way for the design of invisible cloaking devices.

  19. Design of high-speed data transmission system for Lanzhou heavy ion therapy accelerator

    In order to satisfy the transmission requirements of partial synchronization data and process data for the heavy ion therapy accelerator, a high-speed, error-correction, long-distance, and real-time data transmission system was proposed and achieved. It can improve the efficiency and reliability of the accelerator control and synchronization. The system optimizes the hardware configuration and layout of the traditional system. FPGA, gigabit fiber module, PXI and SDRAM are the main parts of the system. It replaces the low-speed, short-distance, and poor anti-interference of the traditional data path and the data processing chips. Through the programming in the two FPGA chips, the PXI and DMA transmission mode was used to exchange data with the server of the accelerator. The front-end of the system achieves a real-time, long-distance, and high-speed serial frame transmission with 800 MHz carrier and 100 MHz base band signal. The real-time -data like synchronous event signal, power waveform data of the heavy ion therapy accelerator can be transmitted efficiently between the server and the remote controller through the system. (authors)

  20. Impact of modulator chirp in 100 Gbps class optical discrete multi-tone transmission system

    Nishihara, Masato; Tanaka, Toshiki; Takahara, Tomoo; Li, Lei; Tao, Zhenning; Rasmussen, Jens C.

    2012-12-01

    Discrete multi-tone (DMT) technology is an attractive modulation technique for short reach optical transmission system. One of the main factors that limit the performance of the 1.5-μm band DMT system is the interplay between the chromatic dispersion of the transmission fiber and the chirp characteristic of the transmitter. We experimentally measured and compared the chirp characteristics of various modulator configurations, which are lithium-niobate Mach-Zehnder modulator, directly modulated laser, and electro-absorption modulator, by the frequency discriminator method using MZ interferometer. We also measured and compared the transmission characteristics of the transmitters using above-mentioned modulators and discuss the suitable transmitter configuration for DMT technology.

  1. Modified EESM Based Link Adaptation Algorithm for Multimedia Transmission in Multicarrier Systems

    Sandanalakshmi, R; Manivannan, K

    2010-01-01

    The previous link adaptation algorithms on ofdm based systems use equal modulation order for all sub carrier index within a block. For multimedia transmission using ofdm as the modulation technique, unequal constellation is used within one ofdm subcarrier block, a set of subcarriers for audio and another set for video transmissions. A generic model has been shown for such a transmission and link adaptation algorithm has been proposed using EESM (Effective Exponential SNR mapping) method as basic method. Mathematical model has been derived for the channel based on bivariate Gaussian distribution in which the amplitude varies two dimensionally in the same envelope. From the Moment generating function of bivariate distribution, Probability of error has been theoretically derived. Results have been shown for BER performance of an ofdm system using unequal constellation. BER performances have been shown for different values of correlation parameter and fading figure.

  2. A test of a 2 Tesla superconducting transmission line magnet system

    Superconducting transmission line magnet test system for an injector accelerator of a staged VLHC proton-proton colliding beam accelerator has been built and operated at Fermilab. The 1.5 m long, twin-aperture, combined function dipole magnet of 2 Tesla field is excited by a single turn 100 kA transmission line superconductor. The 100 kA dc current is generated using dc-dc switching converters powered by a bulk 240 kW supply. A pair of horizontally placed conventional leads facilitates transfer of this current to the magnet transmission line superconductor operating at liquid helium temperature. Fabrication of magnet components and magnet assembly work are described. The magnet test system and its operation are presented, and the performance is summarized

  3. Adaptable System Increasing the Transmission Speed and Reliability in Packet Network by Optimizing Delay

    Zbynek Kocur

    2014-01-01

    Full Text Available There is a great diversity in the transmission technologies in current data networks. Individual technologies are in most cases incompatible at physical and partially also at the link layer of the reference ISO/OSI model. Network compatibility, as the ability to transmit data, is realizable through the third layer, which is able to guarantee the operation of the different devices across their technological differences. The proposed inverse packet multiplexer addresses increase of the speed and reliability of packet transmission to the third layer, and at the same time it increases the stability of the data communication by the regulation of the delay value during the transmission. This article presents implementation of a communication system and its verification in real conditions. The conclusion compares the strengths and weaknesses of the proposed control system.

  4. Remote Control System of the TJ-II Microwave Transmission Lines Mirrors

    The ECRH system of the TJ-II stellarator has two gyrotrons, which deliver a maximum power of 300 kW each at a frequency of 53.2 GHz. Another 28 GHz gyrotron will be used to heat the plasma by electron Bernstein waves (EBWH). The microwave power is transmitted from the gyrotrons to the vacuum chamber by two quasi-optical transmission lines for ECRH and a corrugated waveguide for EBWH. All transmission lines have an internal movable mirror inside the vacuum chamber to focus the beam and to be able to change the launching angle. The control of the beam polarization is very important and the lines have two corrugated mirrors, which actuate as polarizers. In this report the control system of the position of these three internal mirrors and the polarizers of the EBWH transmission line is described. (Author) 20 refs

  5. Study on Seismic Control of Power Transmission Tower-Line Coupled System under Multicomponent Excitations

    Li Tian

    2013-01-01

    Full Text Available The seismic control of power transmission tower-line coupled system subjected to multicomponent excitations is studied in this paper. The schematic of tuned mass damper is introduced, and equations of motion of a system with tuned mass damper under multi-component excitations are proposed. Three-dimensional finite tower-line system models are created based on practical engineering in studying the response of this system without and with control. The time domain analysis takes into account geometric nonlinearity due to finite deformation. The optimal design of the transmission tower-line system with tuned mass damper is obtained according to different mass ratio. The effects of wave travel, coherency loss, and different site conditions on the system without and with control are investigated, respectively.

  6. Transmission Performance Analysis of Fiber Optical Parametric Amplifiers for WDM System

    Xiaohong Jiang

    2009-01-01

    Full Text Available A numerical analysis is presented on the long-haul wavelength-division multiplexing (WDM transmission system employing fiber-optic parametric amplifier (FOPA cascades based on one-pump FOPA model with Raman Effect taken into account. The end-to-end equalization scheme is applied to optimize the system features in terms of proper output powers and signal-to-noise ratios (SNRs in all the channels. The numerical results show that—through adjusting the fiber spans along with the number of FOPAs as well as the channel powers at the terminals in a prescribed way—the transmission distance and system performance can be optimized. By comparing the results generated by different lengths of fiber span, we come to the optimal span length to achieve the best transmission performance. Furthermore, we make a comparison among the long-haul WDM transmission systems employing different inline amplifiers, namely, FOPA, erbium-doped fiber amplifier (EDFA, and Fiber Raman Amplifier (FRA. FOPA demonstrates its advantage over the other two in terms of system features.

  7. Stabilization of Decentralized Networked Complex Systems with Multiple-Packet Transmission

    Bakule, Lubomír; Papík, Martin; Rehák, Branislav

    Piscataway : IEEE, 2013, s. 42-47. ISBN 978-1-4799-1075-5. [the 6th IEEE International Conference on Cybernetics and Intelligent Systems (CIS 2013). Manila & Pico de Loro (PH), 12.11.2013-15.11.2013] R&D Projects: GA ČR GA13-02149S Institutional support: RVO:67985556 Keywords : stabilization * decentralized networked complex systems * multiple-packet transmission Subject RIV: BC - Control Systems Theory

  8. Lumped-element model of a tapered transmission line for impedance matching in a pulsed power system

    Lee, Kun-A.; Ko, Kwang-Cheol

    2016-07-01

    In a pulsed power system, impedance matching is one of the significant factors for increasing the efficiency of the system. One of the most general methods for impedance matching is to use a tapered transmission line. Because the characteristics of a tapered transmission line are changed continuously according to its position, modeling the tapered transmission line by using lumped elements is difficult. In this study, we investigated a tapered transmission line to match the impedance of power supply to that of a load by using lumped elements especially in a pulsed power system. In modeling the tapered transmission line, we used the concept of a transmission, and we introduced an efficient modeling method. We propose a simulation model based on the investigation results. The results of the study will be useful for research on tapered transmission lines.

  9. Harmonic Analysis in the Power System to Reduce Transmission losses and Save Energy

    Apurva Ganguli; Abhay Kumar Sharma

    2014-01-01

    This paper is about the harmonics related to the power system . How it affects the whole transmission, loads connected etc that is whole system.In the below article we have discussed about the harmonic limits for the power system required and the method to mitigate it from the power system . To reduse harmonics from the system we have used 48 pulse Statcom in the substation of 132KV/33KV .The source convertor is being applied to the 33KV side of the system. After the techno-ec...

  10. Novel artificial anal sphincter system based on transcutaneous energy transmission system tested in vivo.

    Wang, Yongbing; Liu, Hua; Xu, Qianqian; Yan, Guozheng

    2013-12-01

    This paper proposes a novel artificial anal sphincter system (AASS) for severe fecal incontinence. The AASS is composed of an artificial anal sphincter (AAS), an external transcutaneous energy transmission system (TETS), and an external control device. The AAS is composed of a cuff, a micropump, a reservoir, and a remote control device. It is designed to be implanted into the body of the patient. The function of the AAS is to open and close the patient's natural anus. Patients suffering from loss of their natural sphincter lose rectal sensation and are thus unable to perceive imminent fecal incontinence. In order to restore rectal sensation, a pressure sensor in the AAS cuff is designed to detect pressure in the colon. The pressure reflects the present quantity of colon contents, allowing patients to control the AAS to open or close the anus according to the pressure. The TETS is designed to provide electrical energy to the implanted AAS without wire connections. The external control device is designed to receive the pressure information from the AAS and send the patient's command to the implanted device. This paper provides a thorough discussion of the design of the novel AASS and describes the performance of the AASS when tested in vivo on two Beagle dogs who were chosen to be the subjects for receiving the implant. The experimental results verified that the performance of the AASS met the functional requirements it was designed for; however, the trial also revealed some challenges to be further studied. PMID:24362899

  11. Lightning location system for power transmission lines; Sodensen rakurai chiten no tanchi system

    Kurihara, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-04-01

    A novel Lightning Location System (LLS) for power transmission lines has been developed. In this system, an optical loop is constituted, wherein a light signal is reflected by an Optical Fiber Composite Ground Wire (OPGW) end, positioned opposite to the incident end, and returns to the incident end. When a lightning lands on an OPGW, the lightning current travels through the steel tower serving as the grounding route and, because the OPGW is a strand of aluminum-clad wires, produces a magnetic field in the OPGW along its longitudinal direction, which causes fluctuations in polarization simultaneously in the light signals traveling, up or down in the opposite directions, through the lightning-struck spot. When the fluctuations are observed at the receiving end, two fluctuations are detected with a certain time difference between the two, and the time difference is the required information because the time difference is equivalent to the time that is twice the time that a light signal requires to travel from the lightning-struck spot to the light-reflecting end. Accordingly, the distance from the lightning-struck spot can be calculated using the observed time difference. In actual observation in a lightning-abundant period of approximately two months and half, fluctuations in polarization were observed 51 times, and there was agreement on the order of second with the LLS lightning detecting time in 43 out of the 51. 5 refs., 3 figs.

  12. Effect of Polarization Dependent Loss on Polarization-Multiplexed Transmission System

    H.; C.; Ji; J.; H.; Lee; K.; J.; Park; Y.; C.; Chung

    2003-01-01

    We report on the effects of the polarization-dependent loss (PDL) on the polarization-multiplexed system. The result shows that the PDL of 0.9 dB could cause 1-dB power penalty. Unlike PMD, the effect of PDL was not dependent on the transmission speed.

  13. Time heteronymous non-linear - cubic damping in internal dynamics of high speed parametric transmission systems

    Hortel, Milan; Škuderová, Alena

    1. Brno : University of Defence Brno, 2011 - (Rosická, Z.; Stodola, J.; Šťastný, J.), s. 65-78 ISBN 978-80-260-0633-6 Institutional research plan: CEZ:AV0Z20760514 Keywords : non- linear dynamics * time variable damping * planetary transmission systems Subject RIV: BI - Acoustics

  14. Theories and technologies of electronic-electrical-mechanical integrated(EEMI)transmission system

    2006-01-01

    @@ EEMI is one of the hot spots in cross-disciplinary research. The research in this topic was to discard the traditional mechanical gear reducer, integrate electrical motor with mechanical load, control the electrical motor by electrical power generated by microelectronics and electrical electronics; namely, form a EEMI transmission system in the mechanical equipments with low rotation rate and large rotation torque.

  15. Sound transmission through pipe systems and into plate structures in buildings. A simplified sea model

    Bron-van der Jagt, G.S.

    2007-01-01

    In the study presented, it has been investigated whether Statistical Energy Analysis (SEA) could be applied in a simplified way as a framework for a prediction model regarding noise due to service equipment, specifically sound transmission within (plastic wastewater) pipe systems and between these p

  16. Power Flow Analysis of HVAC and HVDC Transmission Systems for Offshore WindParks

    da Silva, Filipe Miguel Faria; Castro, Rui

    2009-01-01

    As the onshore wind resource is running shorter, wind power promoters are paying attention to the offshore resources. As in most cases there is no load offshore, wind power must be transmitted to the main land. To do so, two options are available: HVAC and HVDC transmission systems. In this paper...

  17. Stability analysis of transmission system with high penetration of distributed generation

    Reza, M.

    2006-01-01

    Nowadays, interest in generating electricity using decentralized generators of relatively small scale ('distributed generation', DG) is increasing. This work deals with the impact of implementing DG on the transmission system transient stability, with the emphasis on a potential transition from a 'v

  18. A computational model for determining the minimal cost expansion alternatives in transmission systems planning

    A computational model for determining an economical transmission expansion plan, based in the decomposition techniques is presented. The algorithm was used in the Brazilian South System and was able to find an optimal solution, with a low computational resource. Some expansions of this methodology are been investigated: the probabilistic one and the expansion with financier restriction. (C.G.C.). 4 refs, 7 figs

  19. Analysis and Simulation on Current Commutation of DC Transfer Switches in UHVDC Transmission Systems

    PENG Chang; WEN Jialiang; MA Guohua; WANG Xiuhuan; LIU Zhigang; YU Kunshan

    2011-01-01

    The most severe working conditions of transfer switches in HVDC transmission systems identified as below: DC are For MRTB and GRTS, the most severe working condition is the failure of a single pole under operation mode. MRTB has to commutate the current from the ground return to metallic return. GRTS works in the contrary way.

  20. A Seismic Transmission System for Continuous Monitoring of the Lithosphere: A Proposition

    Unger, R.

    2002-01-01

    The main objective of this thesis is to enhance earthquake prediction feasibility. We present the concept and the design layout of a novel seismic transmission system capable of continuously monitoring the Lithosphere for changes in Earth physics parameters governing seismic wave propagation. New-te