WorldWideScience

Sample records for active power control

  1. Active Power Controls from Wind Power: Bridging the Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, V. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fleming, P. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhang, Y. C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Singh, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muljadi, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scholbrook, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Aho, J. [Univ. of Colorado, Boulder, CO (United States); Buckspan, A. [Univ. of Colorado, Boulder, CO (United States); Pao, L. [Univ. of Colorado, Boulder, CO (United States); Singhvi, V. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Tuohy, A. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Pourbeik, P. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Brooks, D. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Bhatt, N. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States)

    2014-01-01

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  2. Piezoelectric Power Requirements for Active Vibration Control

    Science.gov (United States)

    Brennan, Matthew C.; McGowan, Anna-Maria Rivas

    1997-01-01

    This paper presents a method for predicting the power consumption of piezoelectric actuators utilized for active vibration control. Analytical developments and experimental tests show that the maximum power required to control a structure using surface-bonded piezoelectric actuators is independent of the dynamics between the piezoelectric actuator and the host structure. The results demonstrate that for a perfectly-controlled system, the power consumption is a function of the quantity and type of piezoelectric actuators and the voltage and frequency of the control law output signal. Furthermore, as control effectiveness decreases, the power consumption of the piezoelectric actuators decreases. In addition, experimental results revealed a non-linear behavior in the material properties of piezoelectric actuators. The material non- linearity displayed a significant increase in capacitance with an increase in excitation voltage. Tests show that if the non-linearity of the capacitance was accounted for, a conservative estimate of the power can easily be determined.

  3. Power system damping - Structural aspects of controlling active power

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, O.

    1997-04-01

    Environmental and economical aspects make it difficult to build new power lines and to reinforce existing ones. The continued growth in demand for electric power must therefore to a great extent be met by increased loading of available lines. A consequence is that power system damping is reduced, leading to a risk of poorly damped power oscillations between the generators. This thesis proposes the use of controlled active loads to increase damping of such electro-mechanical oscillations. The focus is on structural aspects of controller interaction and of sensor and actuator placement. On-off control based on machine frequency in a single machine infinite bus system is analysed using energy function analysis and phase plane plots. An on-off controller with estimated machine frequency as input has been implemented. At a field test it damped oscillations of a 0.9 MW hydro power generator by controlling a 20kW load. The linear analysis uses two power system models with three and twenty-three machines respectively. Each damper has active power as output and local bus frequency or machine frequency as input. The power system simulator EUROSTAG is used both for generation of the linearized models and for time simulations. Measures of active power mode controllability and phase angle mode observability are obtained from the eigenvectors of the differential-algebraic models. The geographical variation in the network of these quantities is illustrated using the resemblance to bending modes of flexible mechanical structures. Eigenvalue sensitivities are used to determine suitable damper locations. A spring-mass equivalent to an inter-area mode provides analytical expressions, that together with the concept of impedance matching explain the structural behaviour of the power systems. For large gains this is investigated using root locus plots. 64 refs, 99 figs, 20 tabs

  4. Prediction control of active power filters

    Institute of Scientific and Technical Information of China (English)

    王莉娜; 罗安

    2003-01-01

    A prediction method to obtain harmonic reference for active power filter is presented. It is a new use ofthe adaptive predictive filter based on FIR. The delay inherent in digital controller is successfully compensated by u-sing the proposed method, and the computing load is not very large compared with the conventional method. Moreo-ver, no additional hardware is needed. Its DSP-based realization is also presented, which is characterized by time-va-riant rate sampling, quasi synchronous sampling, and synchronous operation among the line frequency, PWM gener-ating and sampling in A/D unit. Synchronous operation releases the limitation on PWM modulation ratio and guar-antees that the electrical noises resulting from the switching operation of IGBTs do not interfere with the sampledcurrent. The simulation and experimental results verify the satisfactory performance of the proposed method.

  5. Model based active power control of a wind turbine

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad;

    2014-01-01

    in the electricity market that selling the reserve power is more profitable than producing with the full capacity. Therefore wind turbines can be down-regulated and sell the differential capacity as the reserve power. In this paper we suggest a model based approach to control wind turbines for active power reference...

  6. Neuro-fuzzy based Controller for Solving Active Power Filter

    Directory of Open Access Journals (Sweden)

    Homayoun Ebrahimian

    2016-03-01

    Full Text Available In this paper, two soft computing techniques by fuzzy logic, neural network are used to design alternative control schemes for switching the APF active power filter (APF. The control of a shunt active power filter designed for harmonic and reactive current mitigation. Application of the mentioned model has been combined by an intelligent algorithm for improving the efficiency of proposed controller. Effectiveness of the proposed method has been applied over test case and shows the validity of proposed model.

  7. Power active filter control based on a resonant disturbance observer

    OpenAIRE

    Ramos Fuentes, German A.; Cortés Romero, John Alexander; Zou, Zhixiang; Costa Castelló, Ramon; Zhou, Keliang

    2015-01-01

    Active filters are power electronics devices used to eliminate harmonics from the distribution network. This article presents an active disturbance rejection control scheme for active filters. The controller is based on a linear disturbance observer combined with a disturbance rejection scheme. The parameter tuning is based on a combined pole placement and an optimal estimation based on Kalman-Bucy filter. Proposed scheme is validated through simulation and experimental work in an active filter.

  8. Indirect control of a single-phase active power filter

    Directory of Open Access Journals (Sweden)

    Mihai CULEA

    2006-12-01

    Full Text Available The control of shunt active power filters using PWM inverters consists in generating a reference by separating, using different methods, the harmonics to be eliminated. The methods used are time-consuming and need dedicated control and signal processing equipments. To avoid these setbacks a new method is proposed in the paper. The active power filter is a current PWM rectifier with voltage output and with a capacitor on the DC side. The PWM rectifier is controlled so that the sum of its current and the load’s current is a sinusoid. The control block as well as simulation results are presented.

  9. Active Power Control of Waked Wind Farms: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    Active power control can be used to balance the total power generated by wind farms with the power consumed on the electricity grid. With the increasing penetration levels of wind energy, there is an increasing need for this ancillary service. In this paper, we show that the tracking of a certain power reference signal provided by the transmission system operator can be significantly improved by using feedback control at the wind farm level. We propose a simple feedback control law that significantly improves the tracking behavior of the total power output of the farm, resulting in higher performance scores. The effectiveness of the proposed feedback controller is demonstrated using high-fidelity computational fluid dynamics simulations of a small wind farm.

  10. Design and control of hybrid active power filters

    CERN Document Server

    Lam, Chi-Seng

    2014-01-01

    Design and Control of Hybrid Active Power Filters presents an overview of the current quality problems and their compensators. To get a balance between the system cost and performance, hybrid active power filters (HAPFs) are valuable. The book presents the coverage of resonance phenomena prevention capability, filtering performance and system robustness analysis of HAPF; nonlinear inverter current slope characteristics and their linear operation region requirement analysis of the hysteresis PWM for the HAPF; minimum inverter capacity design procedure of HAPF, adaptive dc-link voltage controller for the HAPF and the real design example of a 220V 10kVA HAPF, in which the system performance analysis method, minimum dc voltage deduction concept and adaptive dc voltage idea can be further extended into the other active compensators, such as APF, static synchronous compensator STATCOM, etc. This book will benefit researchers, graduate students, and electrical power engineers in the field of power-quality compensati...

  11. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro

    2010-01-01

    , wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe......Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements...

  12. Adaptive Current Control Method for Hybrid Active Power Filter

    Science.gov (United States)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  13. Instantaneous Power Theory with Fourier and Optimal Predictive Controller Design for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Suksan Tiyarachakun

    2014-01-01

    Full Text Available This paper presents a novel harmonic identification algorithm of shunt active power filter for balanced and unbalanced three-phase systems based on the instantaneous power theory called instantaneous power theory with Fourier. Moreover, the optimal design of predictive current controller using an artificial intelligence technique called adaptive Tabu search is also proposed in the paper. These enhancements of the identification and current control parts are the aim of the good performance for shunt active power filter. The good results for harmonic mitigation using the proposed ideas in the paper are confirmed by the intensive simulation using SPS in SIMULINK. The simulation results show that the enhanced shunt active power filter can provide the minimum %THD (Total Harmonic Distortion of source currents and unity power factor after compensation. In addition, the %THD also follows the IEEE Std.519-1992.

  14. The Control of Transmitted Power in an Active Isolation System

    DEFF Research Database (Denmark)

    Elliott, S.J.; Gardonio, P.; Pinnington, R.J.

    1997-01-01

    The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure and distr...... of such an active vibration control system are also discussed.......The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure...... and distributed active mounts, and these models can be connected together to produce an overall theoretical description of a realistic active isolation system. Total transmitted power has been found to be an excellent criterion to quantify the effect of various control strategies in this model in which...

  15. Distributed Model Predictive Control for Active Power Control of Wind Farm

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Rasmussen, Claus Nygaard;

    2014-01-01

    This paper presents the active power control of a wind farm using the Distributed Model Predictive Controller (D- MPC) via dual decomposition. Different from the conventional centralized wind farm control, multiple objectives such as power reference tracking performance and wind turbine load can......-scale wind farm control....

  16. Advanced nonlinear control of three phase series active power filter

    Directory of Open Access Journals (Sweden)

    Abouelmahjoub Y.

    2014-01-01

    Full Text Available The problem of controlling three-phase series active power filter (TPSAPF is addressed in this paper in presence of the perturbations in the voltages of the electrical supply network. The control objective of the TPSAPF is twofold: (i compensation of all voltage perturbations (voltage harmonics, voltage unbalance and voltage sags, (ii regulation of the DC bus voltage of the inverter. A controller formed by two nonlinear regulators is designed, using the Backstepping technique, to provide the above compensation. The regulation of the DC bus voltage of the inverter is ensured by the use of a diode bridge rectifier which its output is in parallel with the DC bus capacitor. The Analysis of controller performances is illustrated by numerical simulation in Matlab/Simulink environment.

  17. DSP control of photovoltaic power generation system adding the function of shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Seo, H.-R.; Kim, K.-H.; Park, Y.-G.; Park, M.; Yu, I.-K. [Changwon National Univ., SarimDong (Korea, Republic of). Dept. of Electrical Engineering

    2007-07-01

    The growing number of power electronics-based equipment has created a problem on the quality of electric power supply since both high power industrial loads and domestic loads cause harmonics in the network voltage. Power quality problems can occur in the system or can be caused by the consumer. Active filter (AF) is widely used to compensate current harmonics and/or current imbalance of harmonic-producing loads. The power output of a photovoltaic (PV) system is directly affected by weather conditions. When alternating current (AC) power supply is required, power conversion by an inverter and an MPPT control is necessary. The proliferation of nonlinear loads such as inverter of PV power generation system can be treated as a harmonic source for the power distribution system. As such, the PV system combined with the function of the active filter system can be useful for the application in power distribution systems. This paper described a PV-AF system using DSP to prove that it is possible to combine AF theory to the three phase PV system connected to utility and verify it through experimental results. The paper described the control method of the PV-AF system, with reference to the photovoltaic power generation system, shunt active filter and PV-AF system. The experimental set-up was also presented. A laboratory system was designed and constructed to confirm the viability of the proposed PV-AF system. The test results revealed the stability and effectiveness of the proposed PV-AF system. 12 refs., 1 tabs., 12 figs.

  18. SEVEN LEVEL CONTROL OF SHUNT ACTIVE POWER FILTER FOR POWER QUALITY ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    G. JAYAKRISHNA

    2011-09-01

    Full Text Available Shunt Active Power Filter (SAPF is one of the controllers to enhance power quality (PQ. This paper presents Hybrid Cascaded Seven-Level Inverter (HCSLI used in SAPF to compensate reactive power, improve the power factor and to suppress the total harmonic distortion (THD in supply current due to linear load and Non- Linear Diode Rectifier Loads (NLDRLs.In this paper d-q reference frame theory for reference current computation, Constant Switching Frequency Multicarrier Sub-Harmonic Pulse Width Modulation (CSFMSHPWM technique for controlling the switches of HCSLI, Fuzzy logic controller (FLC for regulating dc side capacitor voltage are proposed. The results are validated through simulation using Mat Lab/simulink with and without SAPF for linear and nonlinear loads.

  19. Combined Active and Reactive Power Control of Wind Farms based on Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Wang, Jianhui;

    2017-01-01

    This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power control, the proposed control scheme considers the significant impact of active power on voltage variations due to the low X=R ratio...... of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive power, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate...... the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme....

  20. Adaptive Current Control with PI-Fuzzy Compound Controller for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2013-01-01

    Full Text Available An adaptive control technology and PI-fuzzy compound control technology are proposed to control an active power filter (APF. AC side current compensation and DC capacitor voltage tracking control strategy are discussed and analyzed. Model reference adaptive controller for the AC side current compensation is derived and established based on Lyapunov stability theory; proportional and integral (PI fuzzy compound controller is designed for the DC side capacitor voltage control. The adaptive current controller based on PI-fuzzy compound system is compared with the conventional PI controller for active power filter. Simulation results demonstrate the feasibility and satisfactory performance of the proposed control strategies. It is shown that the proposed control method has an excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD, and strong robustness in the presence of parameters variation and nonlinear load.

  1. Dynamic power flow controllers

    Science.gov (United States)

    Divan, Deepakraj M.; Prasai, Anish

    2017-03-07

    Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

  2. Distributed Model Predictive Control of A Wind Farm for Optimal Active Power Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Guo, Qinglai;

    2015-01-01

    This paper presents a dynamic discrete-time Piece- Wise Affine (PWA) model of a wind turbine for the optimal active power control of a wind farm. The control objectives include both the power reference tracking from the system operator and the wind turbine mechanical load minimization. Instead......, which combines the clustering, linear identification and pattern recognition techniques. The developed model, consisting of 47 affine dynamics, is verified by the comparison with a widely-used nonlinear wind turbine model. It can be used as a predictive model for the Model Predictive Control (MPC......) or other advanced optimal control applications of a wind farm....

  3. DPC controlled three-phase active filter for power quality improvement

    Energy Technology Data Exchange (ETDEWEB)

    Chaoui, Abdelmadjid; Krim, Fateh [Laboratoire d' Electronique de Puissance et Commande Industrielle (LEPCI), Universite de Setif (Algeria); Gaubert, Jean-Paul; Rambault, Laurent [Laboratoire d' Automatique et d' Informatique Industrielle (LAII-ESIP), Universite de Poitiers (France)

    2008-10-15

    This paper presents a new control method entitled direct power control (DPC) for shunt active power filtering (5th, 7th, 11th,..) (SAPF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive powers to be compared to references values using hysteresis control. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed control technique. (author)

  4. Sliding Mode Controller for Three-Phase Hybrid Active Power Filter with Photovoltaic Application

    OpenAIRE

    Blorfan, Ayman; Merckle, Jean; Flieller, Damien; Wira, Patrice; Sturtzer, Guy

    2012-01-01

    International audience; This paper presents a new three-phase hybrid active power filter configuration that interconnects a passive high-pass filter in parallel with an active power filter and a photovoltaic system. The proposed configuration can improves the filtering performance of the conventional active power filter, as well as simultaneously supply the power from the photovoltaic arrays to the load and utility. This paper will describe the proposed hybrid active power filter control usin...

  5. Control System Design of Shunt Active Power Filter Based on Active Disturbance Rejection and Repetitive Control Techniques

    OpenAIRE

    Le Ge; Xiaodong Yuan; Zhong Yang

    2014-01-01

    To rely on joint active disturbance rejection control (ADRC) and repetitive control (RC), in this paper, a compound control law for active power filter (APF) current control system is proposed. According to the theory of ADRC, the uncertainties in the model and from the circumstance outside are considered as the unknown disturbance to the system. The extended state observer can evaluate the unknown disturbance. Next, RC is introduced into current loop to improve the steady characteristics. Th...

  6. Indirect Control of a low power Single-Phase Active Power Filter

    Directory of Open Access Journals (Sweden)

    SILVIU EPURE

    2010-12-01

    Full Text Available This paper deals with a low power, single phase active filter used to compensate nonlinear loads. The filter uses the indirect control method and it is based on a particular connection between filter, polluting load and grid to avoid timeconsuming mathematic operations or signal processing computations and assures good rejection of harmonic currents injected by the nonlinear load into the grid. A scale model was first simulated in Simulink and then physically implemented. The paper presents simulation and experimental results, and highlight problems encountered during experiments.

  7. Bias Errors in Measurement of Vibratory Power and Implication for Active Control of Structural Vibration

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Henriksen, Eigil; Laugesen, Søren

    1997-01-01

    control of vibratory power transmission into structures. This is demonstrated by computer simulations using a theoretical model of a beam structure which is driven by one primary source and two control sources. These simulations reveal the influence of residual errors on power measurements......, and the limitations imposed in active control of structural vibration based upon a strategy of power minimisation....

  8. Power quality improvement using DPC controlled three-phase shunt active filter

    Energy Technology Data Exchange (ETDEWEB)

    Chaoui, Abdelmadjid [Laboratoire d' Automatique et d' Informatique Industrielle (LAII-ESIP), Universite de Poitiers (France); Gaubert, Jean-Paul; Krim, Fateh [Laboratoire d' Electronique de Puissance et Commande Industrielle (LEPCI), Universite de Setif (Algeria)

    2010-06-15

    This paper presents a new control method entitled direct power control (DPC) for shunt active power filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive source powers to be compared to references values using hysteresis control. The active power reference is issue of DC-side of inverter and reactive power reference is set to zero for unity power factor. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed technique. (author)

  9. Distributed Power Flow Controller

    NARCIS (Netherlands)

    Yuan, Z.

    2010-01-01

    In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of P

  10. Distributed Power Flow Controller

    NARCIS (Netherlands)

    Yuan, Z.

    2010-01-01

    In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of P

  11. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

    Directory of Open Access Journals (Sweden)

    Josef Tlustý

    2010-01-01

    Full Text Available The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loads in different parts of the power system.

  12. Impact of thermostatically controlled loads' demand response activation on aggregated power: A field experiment

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Kosek, Anna Magdalena;

    2015-01-01

    This paper describes the impacts of different types of DR (demand response) activation on TCLs' (thermostatically controlled loads) aggregated power. The different parties: power system operators, DR service providers (or aggregators) and consumers, have different objectives in relation to DR...

  13. Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buckspan, A.; Aho, J.; Pao, L.; Fleming, P.; Jeong, Y.

    2012-06-01

    Wind energy is becoming a larger portion of the global energy portfolio and wind penetration has increased dramatically in certain regions of the world. This increasing wind penetration has driven the need for wind turbines to provide active power control (APC) services to the local utility grid, as wind turbines do not intrinsically provide frequency regulation services that are common with traditional generators. It is common for large scale wind turbines to be decoupled from the utility grid via power electronics, which allows the turbine to synthesize APC commands via control of the generator torque and blade pitch commands. Consequently, the APC services provided by a wind turbine can be more flexible than those provided by conventional generators. This paper focuses on the development and implementation of both static and dynamic droop curves to measure grid frequency and output delta power reference signals to a novel power set point tracking control system. The combined droop curve and power tracking controller is simulated and comparisons are made between simulations using various droop curve parameters and stochastic wind conditions. The tradeoffs involved with aggressive response to frequency events are analyzed. At the turbine level, simulations are performed to analyze induced structural loads. At the grid level, simulations test a wind plant's response to a dip in grid frequency.

  14. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  15. Hysteresis Current Control technique based on Space Vector Modulation for Active Power Filter

    Directory of Open Access Journals (Sweden)

    Wang Yun-liang

    2011-09-01

    Full Text Available In this paper, the hysteresis current control (HCC technique based on space vector modulation (SVM for shunt active power filter (APF is proposed. The switching control algorithms of the HCC based SVM manage to generate compensated current according to the reference current. Harmonics extraction is based on the instantaneous active and reactive power theorem in time domain by calculating the power compensation. A closed loop control system is carried out and the error current is the difference between the reference current which is obtained from the power compensation and the actual current needs to be injected back into the power grid. By implementing this control strategy, the APF manages to generate better compensated harmonics currents to the power grid. Keywords: active power filter, hysteresis current control, space vector modulation ,matlab/simulink

  16. Development of Control Structure for Hybrid Wind Generators with Active Power Capability

    Directory of Open Access Journals (Sweden)

    Mehdi Niroomand

    2014-01-01

    Full Text Available A hierarchical control structure is proposed for hybrid energy systems (HES which consist of wind energy system (WES and energy storage system (ESS. The proposed multilevel control structure consists of four blocks: reference generation and mode select, power balancing, control algorithms, and switching control blocks. A high performance power management strategy is used for the system. Also, the proposed system is analyzed as an active power filter (APF with ability to control the voltage, to compensate the harmonics, and to deliver active power. The HES is designed with parallel DC coupled structure. Simulation results are shown for verification of the theoretical analysis.

  17. Control of high power IGBT modules in the active region for fast pulsed power converters

    CERN Document Server

    Cravero, J M; Garcia Retegui, R; Maestri, S; Uicich, G

    2014-01-01

    At CERN, fast pulsed power converters are used to supply trapezoidal current in different magnet loads. These converters perform output current regulation by using a high power IGBT module in its ohmic region. This paper presents a new strategy for pulsed current control applications using a specifically designed IGBT driver.

  18. Tutorial of Wind Turbine Control for Supporting Grid Frequency through Active Power Control: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Aho, J.; Buckspan, A.; Laks, J.; Fleming, P.; Jeong, Y.; Dunne, F.; Churchfield, M.; Pao, L.; Johnson, K.

    2012-03-01

    As wind energy becomes a larger portion of the world's energy portfolio and wind turbines become larger and more expensive, wind turbine control systems play an ever more prominent role in the design and deployment of wind turbines. The goals of traditional wind turbine control systems are maximizing energy production while protecting the wind turbine components. As more wind generation is installed there is an increasing interest in wind turbines actively controlling their power output in order to meet power setpoints and to participate in frequency regulation for the utility grid. This capability will be beneficial for grid operators, as it seems possible that wind turbines can be more effective at providing some of these services than traditional power plants. Furthermore, establishing an ancillary market for such regulation can be beneficial for wind plant owner/operators and manufacturers that provide such services. In this tutorial paper we provide an overview of basic wind turbine control systems and highlight recent industry trends and research in wind turbine control systems for grid integration and frequency stability.

  19. Fuzzy logic controller based three-phase shunt active power filter under unbalanced network

    Energy Technology Data Exchange (ETDEWEB)

    Belaidi, R.; Chikouche, A.; Fathi, M. [Unite de Developpement des Equipements Solaires (Algeria); Haddouche, A.; Guendouz, A. [Universite Badji Mokhtar (Algeria)], E-mail: rachidi3434@yahoo.fr

    2011-07-01

    In recent years, public awareness of power quality issues in distribution systems has arisen. The photovoltaic interactive shunt active power filter is a system which provides harmonic current damping and reactive power compensation and a fuzzy logic controller was created to adjust the energy storage of the DC voltage; the aim of this paper is to study the performance of the fuzzy logic controller. Simulations were performed using Matlab and Simulink and were analyzed to determine the effectiveness of the system; the instantaneous reactive power theory was utilized. Results showed that the use of the fuzzy logic controller achieves a reduction of the total harmonic distortion of the current from 26.54% to 2.27%. This study demonstrated that the fuzzy logic controller combined with the photovoltaic interactive shunt active power filter helps improve power quality by filtering harmonic currents and compensating reactive power generated by non-linear loads.

  20. Design and control of LCL-filter with active damping for Active Power Filter

    DEFF Research Database (Denmark)

    Zeng, Guohong; Rasmussen, Tonny Wederberg; Ma, L

    2010-01-01

    In the application of shunt Active Power Filter (APF) to compensate nonlinear load's harmonic, reactive and negative sequence current, it is more effective to use a LCL-filter than an L-filter as an interface between the Voltage Source Converter (VSC) and grid. In this paper, a designing procedure...... of LCL-filter for APF is introduced, which is aimed for simplified the implementation. To suppress the resonance that may be excited in the system, which brings in stability problems, an active damping control strategy using the current feed-back of the filter capacitor is adopted. By selecting two equal...

  1. Active Power and DC-link Voltage Coordinative Control for Cascaded DC-AC Converter with Bidirectional Power Application

    DEFF Research Database (Denmark)

    Tian, Yanjun; Chen, Zhe; Deng, Fujin;

    2015-01-01

    Two stage cascaded converters are widely used in DC/AC hybrid systems to achieve the bidirectional power transmission. The topology of dual active bridge cascaded with inverter (DABCI) is commonly used in this application. This paper proposes a coordinative control method for DABCI and it’s able...... to reduce the DC-link voltage fluctuation between the DAB and inverter, then reduce the stress on the switching devices, as well as improve the system dynamic performance. In the proposed control method, the DAB and inverter are coordinated to control the DC-link voltage and the power......, and this responsibility sharing control can effectively suppress the impact of the power variation on the DC-link voltage, without sacrificing stability. The proposed control method is also effective for DABCI in unidirectional power transmission. The effectiveness of the propose control has been validated by both...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  3. Design and real time implementation of fuzzy switched controller for single phase active power filter.

    Science.gov (United States)

    Afghoul, Hamza; Krim, Fateh; Chikouche, Djamel; Beddar, Antar

    2015-09-01

    This paper proposes a novel fuzzy switched controller (FSC) integrated in direct current control (DCC) algorithm for single phase active power filter (SPAPF). The controller under study consists of conventional PI controller, fractional order PI controller (FO-PI) and fuzzy decision maker (FDM) that switches between them using reduced fuzzy logic control. The proposed controller offers short response time with low damping and deals efficiently with the external disturbances while preserving the robustness properties. To fulfill the requirements of power quality, unity power factor and harmonics limitations in active power filtering an experimental test bench has been built using dSPACE 1104 to demonstrate the feasibility and effectiveness of the proposed controller. The obtained results present high performance in steady and transient states. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Adaptive-Fuzzy Controller Based Shunt Active Filter for Power Line Conditioners

    Directory of Open Access Journals (Sweden)

    KamalaKanta Mahapatra

    2011-08-01

    Full Text Available This paper presents a novel Fuzzy Logic Controller (FLC in conjunction with Phase Locked Loop (PLL based shunt active filter for Power Line Conditioners (PLCs to improve the power quality in the distribution system. The active filter is implemented with current controlled Voltage Source Inverter (VSI for compensating current harmonics and reactive power at the point of common coupling. The VSI gate control switching pulses are derived from proposed Adaptive-Fuzzy-Hysteresis Current Controller (HCC and this method calculates the hysteresis bandwidth effectively using fuzzy logic. The bandwidth can be adjusted based on compensation current variation, which is used to optimize the required switching frequency and improves active filter substantially. These shunt active power filter system is investigated and verified under steady and transient-state with non-linear load conditions. This shunt active filter is in compliance with IEEE 519 and IEC 61000-3 recommended harmonic standards.

  5. Control System Design of Shunt Active Power Filter Based on Active Disturbance Rejection and Repetitive Control Techniques

    Directory of Open Access Journals (Sweden)

    Le Ge

    2014-01-01

    Full Text Available To rely on joint active disturbance rejection control (ADRC and repetitive control (RC, in this paper, a compound control law for active power filter (APF current control system is proposed. According to the theory of ADRC, the uncertainties in the model and from the circumstance outside are considered as the unknown disturbance to the system. The extended state observer can evaluate the unknown disturbance. Next, RC is introduced into current loop to improve the steady characteristics. The ADRC is used to get a good dynamic performance, and RC is used to get a good static performance. A good simulation result is got through choosing and changing the parameters, and the feasibility, adaptability, and robustness of the control are testified by this result.

  6. Rapid Active Power Control of Photovoltaic Systems for Grid Frequency Support

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson; Shirazi, Mariko; Chakraborty, Sudipta; Muljadi, Eduard; Maksimovic, Dragan

    2017-01-01

    As deployment of power electronic coupled generation such as photovoltaic (PV) systems increases, grid operators have shown increasing interest in calling on inverter-coupled generation to help mitigate frequency contingency events by rapidly surging active power into the grid. When responding to contingency events, the faster the active power is provided, the more effective it may be for arresting the frequency event. This paper proposes a predictive PV inverter control method for very fast and accurate control of active power. This rapid active power control method will increase the effectiveness of various higher-level controls designed to mitigate grid frequency contingency events, including fast power-frequency droop, inertia emulation, and fast frequency response, without the need for energy storage. The rapid active power control method, coupled with a maximum power point estimation method, is implemented in a prototype PV inverter connected to a PV array. The prototype inverter's response to various frequency events is experimentally confirmed to be fast (beginning within 2 line cycles and completing within 4.5 line cycles of a severe test event) and accurate (below 2% steady-state error).

  7. Power control of a wind farm with active stall wind turbines and AC grid connection

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Sørensen, Poul; Iov, Florin

    This paper describes the design of a centralised wind farm controller for a wind farm made-up exclusively of active stall wind turbines with AC grid connection. The overall aim of such controller is to enable the wind farms to provide the best grid support. The designed wind farm control involves...... both the control on wind turbine level as well as the central control on the wind farm level. The ability of active stall wind farms with AC grid connection to regulate the power production to the reference power ordered by the operators is assessed and discussed by means of simulations....

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

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Dragicevic, Tomislav;

    2014-01-01

    , an autonomous active power control strategy is proposed for AC islanded microgrids in order to achieve power management in a decentralized manner. The proposed control algorithm is based on frequency bus-signaling of ESS and uses only local measurements for power distribution among microgrid elements. Moreover......, this paper also presents a hierarchical control structure for AC microgrids that is able to integrate the ESS, PV systems and loads. Hereby, basic power management function is realized locally in primary level, while strict frequency regulation can be achieved by using additional secondary controller......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 paper...

  9. Active Lubrication for Reducing Wear and Vibration: A combination of Fluid Power Control and Tribology

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2002-01-01

    The use of fluid power to reduce and control rotor vibration in rotating machines is investigated. An active hybrid bearing is studied, whose main objective is to reduce wear and vibration between rotating and stationary machinery parts. By injecting pressurised oil into the oil film, through...... with experiment, and simulations show the feasibility of controlling shaft vibration through this active device....

  10. Multi-Rate Fractional-Order Repetitive Control of Shunt Active Power Filter

    DEFF Research Database (Denmark)

    Xie, Chuan; Zhao, Xin; Savaghebi, Mehdi

    2017-01-01

    This paper presents a multi-rate fractional-order repetitive control (MRFORC) scheme for three-phase shunt active power filter (APF). The proposed APF control scheme includes an inner proportional-integral (PI) control loop with a sampling rate identical to switching frequency and an external plug-in...

  11. Frequency Response Analysis of Current Controllers for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, C.; Asiminoaei, L.; Boldea, I.;

    2009-01-01

    This paper compares four current control structures for selective harmonic compensation in active power filters. All controllers under scrutiny perform the harmonic compensation by using arrays of resonant controllers, one for the fundamental and one for each harmonic of interest, in order to ach...

  12. A control architecture to coordinate distributed generators and active power filters coexisting in a microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  13. A Control Architecture to Coordinate Distributed Generators and Active Power Filters Coexisting in a Microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  14. Design of a Wireless Gesture Activated PowerPoint Controller

    OpenAIRE

    Wasswa, Charles

    2011-01-01

    The desire to give effective presentations lead to the development of different types of visual aids including flip charts, overhead transparencies, posters and digital slide shows. The digital slide shows had improved the effectiveness of the presentation and the audience size, but the need to be next to the keyboard or mouse, created a vacuum for new innovations. There was a need for some form of wireless control of the slides movement. Presenters have always wanted the freedom of movemen...

  15. Bias Errors in Measurement of Vibratory Power and Implication for Active Control of Structural Vibration

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Henriksen, Eigil; Laugesen, Søren

    1997-01-01

    of a degree for the phase. This implies that input power at a single point can be measured to within one dB in practical structures which possesses some damping. The uncertainty is increased, however, when sums of measured power contributions from more sources are to be minimised, as is the case in active...... control of vibratory power transmission into structures. This is demonstrated by computer simulations using a theoretical model of a beam structure which is driven by one primary source and two control sources. These simulations reveal the influence of residual errors on power measurements......, and the limitations imposed in active control of structural vibration based upon a strategy of power minimisation....

  16. PASSIVE-ACTIVE CONTROL OF POWER FLOW IN AN ISOLATION SYSTEM MOUNTED ON FLEXIBLE FOUNDATIONS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A general model of flexible isolation systems which involves both the passive and active control factors is established by inserting actuators into an passive isolation system. And the power flow transmission function in such a system as with multi-disturbance, multi-mounts, passive isolators and actuators is deduced. By means of the numerical simulation method, the influence of actuators on power flow transmission characteristic is studied. And as a conclusion, the passive-active synthetic control strategy of power flow is summarized.

  17. Active Participation of Air Conditioners in Power System Frequency Control Considering Users’ Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Rongxiang Zhang

    2015-09-01

    Full Text Available Air conditioners have great potential to participate in power system frequency control. This paper proposes a control strategy to facilitate the active participation of air conditioners. For each air conditioner, a decentralized control law is designed to adjust its temperature set point in response to the system frequency deviation. The decentralized control law accounts for the user’s thermal comfort that is evaluated by a fuzzy algorithm. The aggregation of air conditioners’ response is conducted by using the Monte Carlo simulation method. A structure preserving model is applied to the multi-bus power system, in which air conditioners are aggregated at certain load buses. An inner-outer iteration scheme is adopted to solve power system dynamics. An experiment is conducted on a test air conditioner to examine the performance of the proposed decentralized control law. Simulation results on a test power system verify the effectiveness of the proposed strategy for air conditioners participating in frequency control.

  18. Hybrid Active and Passive Control of Vibratory Power Flow in Flexible Isolation System

    Directory of Open Access Journals (Sweden)

    Y.P. Xiong

    2000-01-01

    Full Text Available A hybrid active and passive vibration control strategy is developed to reduce the total power flows from machines, subject to multiple excitations, to supporting flexible structures. The dynamic interactions between machines, controllers, and receiving structures are studied. A force feedback control process governed by a proportional control law is adopted to produce active control forces to cancel the transmitted forces in the mounts. Computational simulations of a simple and a multiple dimensional hybrid vibration isolation system are performed to study the force transmissibility and the total power flows from vibration sources through active and passive isolators to the supporting structures. The investigation focuses on the effects of a hybrid control approach to the reduction of power flow transmissions and the influence of the dynamic characteristics of the control on power flow spectra. The hybrid control mechanism is synthesised from the power flow analysis. Conclusions and control strategies, well supported by numerical simulations, are deduced providing very useful guidelines for hybrid vibration isolation design.

  19. Adaptive active control of structural vibration by minimisation of total supplied power

    DEFF Research Database (Denmark)

    Henriksen, Eigil

    1996-01-01

    Active control of vibration by minimisation of total supplied power is an attractive approach from a theoretical point of view. In this practical study of the method two secondary sources were applied to control the sinusoidal excitation of an aluminium beam from a single primary source...

  20. Active Power Control of Wind Turbines for Ancillary Services: A Comparison of Pitch and Torque Control Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Aho, Jacob; Fleming, Paul; Pao, Lucy Y.

    2016-08-01

    As wind energy generation becomes more prevalent in some regions, there is increased demand for wind power plants to provide ancillary services, which are essential for grid reliability. This paper compares two different wind turbine control methodologies to provide active power control (APC) ancillary services, which include derating or curtailing power generation, providing automatic generation control (AGC), and providing primary frequency control (PFC). The torque APC controller provides all power control through the power electronics whereas the pitch APC controller uses the blade pitch actuators as the primary means of power control. These controllers are simulated under various wind conditions with different derating set points and AGC participation levels. The metrics used to compare their performance are the damage equivalent loads (DELs) induced on the structural components and AGC performance metrics, which are used to determine the payments for AGC services by system operators in the United States. The simulation results show that derating the turbine reduces structural loads for both control methods, with the APC pitch control providing larger reductions in DELs, lower AGC performance scores, and higher root-mean-square pitch rates. Providing AGC increases the structural loads when compared to only derating the turbine, but even the AGC DELs are generally lower than those of the baseline control system. The torque APC control methodology also allows for more sustained PFC responses under certain derating conditions.

  1. Computational Fluid Dynamics Simulation Study of Active Power Control in Wind Plants

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Paul; Aho, Jake; Gebraad, Pieter; Pao, Lucy; Zhang, Yingchen

    2016-08-01

    This paper presents an analysis performed on a wind plant's ability to provide active power control services using a high-fidelity computational fluid dynamics-based wind plant simulator. This approach allows examination of the impact on wind turbine wake interactions within a wind plant on performance of the wind plant controller. The paper investigates several control methods for improving performance in waked conditions. One method uses wind plant wake controls, an active field of research in which wind turbine control systems are coordinated to account for their wakes, to improve the overall performance. Results demonstrate the challenge of providing active power control in waked conditions but also the potential methods for improving this performance.

  2. Control strategies of active filters in the context of power conditioning

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.;

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Various topologies and control schemes have been documented aiming at reducing the cost and improving the performance of the compensation system. Hybrid active filters inherit the efficiency of passive filters and the improved...... performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter is studied for current harmonic compensation. The hybrid filter is formed by a single tuned LC filter per phase and a small-rated power three-phase active filter...

  3. Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

    Science.gov (United States)

    Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

    2014-01-01

    This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

  4. Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

    DEFF Research Database (Denmark)

    Zou, Zhixiang; Wang, Zheng; Cheng, Ming;

    2012-01-01

    This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...... results on a laboratory setup are given to verify the proposed control scheme....

  5. Active Power Control Simulation Platform Research of Wind Farm Based on Multi-Agent

    Directory of Open Access Journals (Sweden)

    Liu Xingjie

    2015-01-01

    Full Text Available The realization of the automation, routinization and intelligentization of dispatch control in wind farms is the key to the integration of wind farms into power grid management system. Active power regulate and control system in wind farms has increasingly high demand on timeliness, but at present this system is mostly equipped with centralized unidirectional control with poor timeliness and low utilization ratio for wind energy resources. The characteristics of distribution and instantaneity owned by the active power regulate and control system in wind farms are highly consistent with Multi-Agent system. This paper discusses a kind of processing method that is used in real-time, distributed and parallel computation and processing for multiple simultaneously running wind turbines, which is based on Multi-Agent technology and adopting JADE development platform. This method converts massive centralized computation to distributed computation, which optimizes the effect of the power control. This method makes the effectiveness of active power regulate and control system better, wins time for timely allocating electricity generation assignments and dealing with problems, and avoids the heavy loss of resources.

  6. Demonstration of Active Power Controls by Utility-Scale PV Power Plant in an Island Grid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; O' Neill, Barbara

    2017-02-01

    The National Renewable Energy Laboratory (NREL), AES, and the Puerto Rico Electric Power Authority conducted a demonstration project on a utility-scale photovoltaic (PV) plant to test the viability of providing important ancillary services from this facility. As solar generation increases globally, there is a need for innovation and increased operational flexibility. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, it may mitigate the impact of its variability on the grid and contribute to important system requirements more like traditional generators. In 2015, testing was completed on a 20-MW AES plant in Puerto Rico, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to provide various types of new grid-friendly controls. This data showed how active power controls can leverage PV's value from being simply an intermittent energy resource to providing additional ancillary services for an isolated island grid. Specifically, the tests conducted included PV plant participation in automatic generation control, provision of droop response, and fast frequency response.

  7. Neural network controlled three-phase four-wire shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Elmitwally, A.; Abdelkader, S. [Mansura University (Egypt); El-Kateb, M. [Bath University (United Kingdom). Dept. of Electronic and Electrical Engineering

    2000-03-01

    A three-phase four-wire shunt active power filter for harmonic mitigation and reactive power compensation in power systems supplying nonlinear loads is presented. Three adaptive linear neurons are used to tackle the desired three-phase filter current templates. Another feedforward three layer neural network is adopted to control the output filter compensating currents online. This is accomplished by producing the appropriate switching patterns of the converter's legs IGBTs. Adequate tracking of the filter current references is obtained by this method. The active filter inject the current required to compensate for the harmonic and reactive components of the line currents. Simulation results of the proposed active filter indicate a remarkable improvement in the source current waveforms. This is reflected in the enhancement of the unified power quality index defined. Also, the filter has exhibited quite a high dynamic response for step variations in the load current assuring its potential for real-time applications. (author)

  8. Independent Control of Active and Reactive Powers of a DFIG Based Wind Energy Conversion System by Vector Control

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmad A

    2015-03-01

    Full Text Available The paper deals with a design and implementation of a doubly fed induction generator (DFIG wind energy conversion system (WECS connected to the power grid. A back-to-back AC/DC/AC converter is incorporated between the stator and the rotor windings of a DFIG, in order to obtain variable speed operation. The DFIG can be controlled from sub-synchronous speed to super synchronous speed operation. The main objective of the paper is to control the flow of the Active and Reactive powers produced by the DFIG based wind energy conversion system. A vector control strategy with stator flux orientation is applied to both the grid side converter and the rotor side converter for the independent control of Active and reactive powers produced by the DFIG based wind energy conversion system. The system along with its control circuit were simulated in a Matlab/simulink and the results are presented and discussed.

  9. Shunt hybrid active power filter under nonideal voltage based on fuzzy logic controller

    Science.gov (United States)

    Dey, Papan; Mekhilef, Saad

    2016-09-01

    In this paper, a synchronous reference frame (SRF) method based on a modified phase lock loop (PLL) circuit is developed for a three-phase four-wire shunt hybrid active power filter (APF). Its performance is analysed under unbalanced grid conditions. The dominant lower order harmonics as well as reactive power can be compensated by the passive elements, whereas the active part mitigates the remaining distortions and improves the power quality. As different control methods show contradictory performance, fuzzy logic controller is considered here for DC-link voltage regulation of the inverter. Extensive simulations of the proposed technique are carried out in a MATLAB-SIMULINK environment. A laboratory prototype has been built on dSPACE1104 platform to verify the feasibility of the suggested SHAPF controller. The simulation and experimental results validate the effectiveness of the proposed technique.

  10. Control of a Shunt Active Power Filter with Neural Networks—Theory and Practical Results

    Science.gov (United States)

    Villalva, Marcelo G.; Filho, Ernesto Ruppert

    This paper presents theoretical studies and practical results obtained with a four-wire shunt active power filter fully controlled with neural networks. The paper is focused on a current compensation method based on adaptive linear elements (adalines), which are powerful and easy-to-use neural networks. The reader will find here an introduction about these networks, an explanatory section about the achievement of Fourier series with adalines, and the full description of an adaline-based selective current compensator. The paper also brings a quick discussion about the use of a feedforward neural network in the current controller of the active filter, as well as simulation and experimental results obtained with the prototype of an active power filter.

  11. Active Lubrication for Reducing Wear and Vibration: A combination of Fluid Power Control and Tribology

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2002-01-01

    The use of fluid power to reduce and control rotor vibration in rotating machines is investigated. An active hybrid bearing is studied, whose main objective is to reduce wear and vibration between rotating and stationary machinery parts. By injecting pressurised oil into the oil film, through ori...

  12. Different View on PQ Theory Used in the Control Algorithm of Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rastislav Pavlanin

    2006-01-01

    Full Text Available The improvement of power quality is a frequently discussed issue, which still requires a considerable research effort to be devoted to the study of the problem. The aim of this paper is to describe some problems related to the control of switching compensators, commonly known as active power filters. It also includes some shortcomings of pq theory regarded as three phase instantaneous power theory. The term “shortcomings” means that the pq theory does not provide a proper description of power properties. Moreover the control algorithm based on this theory only achieves satisfactory results for sinusoidal balanced voltage system. Nevertheless it can still be considered a helpful approach to the problem under study. The simulation results presented in this paper illustrate the weaknesses of the pq theory.

  13. Nonlinear disturbance attenuation control for four-leg active power filter based on voltage source inverter

    Institute of Scientific and Technical Information of China (English)

    Juming CHEN; Feng LIU; Shengwei MEI

    2006-01-01

    Active power filter (APF) based on voltage source inverter (VSI) is one of the important measures for handling the power quality problem. Mathematically, the APF model in a power grid is a typical nonlinear one. The idea of passivity is a powerful tool to study the stabilization of such a nonlinear system. In this paper, a state-space model of the four-leg APF is derived, based on which a new H-infinity controller for current tracking is proposed from the passivity point of view. It can achieve not only asymptotic tracking, but also disturbance attenuation in the sense of L2-gain. Subsequently,a sufficient condition to guarantee the boundedness and desired mean of the DC voltage is also given. This straightforward condition is consistent with the power-balancing law of electrical circuits. Simulations performed on PSCAD platform verify the validity of the new approach.

  14. Active and Reactive Power Control of a Doubly Fed Induction Generator

    Directory of Open Access Journals (Sweden)

    Zerzouri Nora

    2014-10-01

    Full Text Available Wind turbine WT occupies gradually a large part in world energy market, Doubly fed induction generator DFIG is mostly used in WT, it allow highly flexible active and reactive power generation control. This paper presents dynamic modeling and simulation of a doubly fed induction generator based on grid-side and rotor-side converter control. The DFIG, grid-side converter, rotor-side converter, and its controllers are performed in MATLAB/Simulink software. Dynamic response in grid connected mode for variable speed wind operation is investigated. Simulation results on a 3 MW DFIG system are provided to demonstrate the effectiveness of the proposed control strategy during variations of active and reactive power, rotor speed, and converter dc link voltage.

  15. Neuro-Fuzzy based Controller for a Three- Phase Four-Wire Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Mridul Jha

    2011-10-01

    Full Text Available This paper describes the application of a novel neuro-fuzzy based control strategy which is used in order to improve the Active Power Filter (APF dynamics to minimize the harmonics for wide range of variations of load current under various conditions. To improve dynamic behavior of a three phase four-wire shunt active power filter and its robustness under range of load variations, adaptive hysteresis band with instantaneous p-q theory is used with the inclusion of neural network filter for reference current generation and fuzzy logic controller for DC voltage control. The proposed control scheme for “split-capacitor” converter topology is simple and also capable of maintaining the compensated line currents balanced, irrespective of unbalancing in the source voltages & deviation in the capacitor voltages. The results presented in MATLAB-SIMULINK software in this paper clearly reflect the effectiveness of the proposed APF to meet the IEEE-519 standard recommendations on harmonic levels.

  16. Electric space heating scheduling for real-time explicit power control in active distribution networks

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes

    2015-01-01

    This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach...... is developed within the context of a previously defined microgrid control framework, called COMMELEC, conceived for the explicit and real-time control of these specific networks. The designed control algorithm is totally independent from the need of a building model and allows exploiting the intrinsic thermal...

  17. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.;

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately...... estimate the active/reactive power values. The proposed control system enables the hybrid renewable energy generation system to be able to perform real-time grid interconnection services such as active voltage regulation, active power control, and fault ride-through.Simulation and experimental results...... demonstrate the superior performance of the proposed closed-loop control system....

  18. Optimal Active Power Control of A Wind Farm Equipped with Energy Storage System based on Distributed Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Guo, Qinglai

    2016-01-01

    This paper presents the Distributed Model Predictive Control (D-MPC) of a wind farm equipped with fast and short-term Energy Storage System (ESS) for optimal active power control using the fast gradient method via dual decomposition. The primary objective of the D-MPC control of the wind farm...... is power reference tracking from system operators. Besides, by optimal distribution of the power references to individual wind turbines and the ESS unit, the wind turbine mechanical loads are alleviated. With the fast gradient method, the convergence rate of the DMPC is significantly improved which leads...... is independent from the wind farm size and is suitable for the real-time control of the wind farm with ESS....

  19. Adaptive RBF Neural Network Control for Three-Phase Active Power Filter

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2013-05-01

    Full Text Available Abstract An adaptive radial basis function (RBF neural network control system for three-phase active power filter (APF is proposed to eliminate harmonics. Compensation current is generated to track command current so as to eliminate the harmonic current of non-linear load and improve the quality of the power system. The asymptotical stability of the APF system can be guaranteed with the proposed adaptive neural network strategy. The parameters of the neural network can be adaptively updated to achieve the desired tracking task. The simulation results demonstrate good performance, for example showing small current tracking error, reduced total harmonic distortion (THD, improved accuracy and strong robustness in the presence of parameters variation and nonlinear load. It is shown that the adaptive RBF neural network control system for three-phase APF gives better control than hysteresis control.

  20. Active Power Optimal Control of Wind Turbines with Doubly Fed Inductive Generators Based on Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Guo Jiuwang

    2015-01-01

    Full Text Available Because of the randomness and fluctuation of wind energy, as well as the impact of strongly nonlinear characteristic of variable speed constant frequency (VSCF wind power generation system with doubly fed induction generators (DFIG, traditional active power control strategies are difficult to achieve high precision control and the output power of wind turbines is more fluctuated. In order to improve the quality of output electric energy of doubly fed wind turbines, on the basis of analyzing the operating principles and dynamic characteristics of doubly fed wind turbines, this paper proposes a new active power optimal control method of doubly fed wind turbines based on predictive control theory. This method uses state space model of wind turbines, based on the prediction of the future state of wind turbines, moves horizon optimization, and meanwhile, gets the control signals of pitch angle and generator torque. Simulation results show that the proposed control strategies can guarantee the utilization efficiency for wind energy. Simultaneously, they can improve operation stability of wind turbines and the quality of electric energy.

  1. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    OpenAIRE

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.; Jain, Praveen

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications.The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately estimate the active/reactive power values. The proposed control system enables the hybrid renewable energy generation system to be able to perform real-time grid interconnection services such as active v...

  2. Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/Dc Converter

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Pandey

    2017-02-01

    Full Text Available In this paper the simulation of Shunt Active power Filter using P-Q theory and PI controller has been presented. This SAPF compensates the harmonic currents drawn by three phase six pulse AC/DC converter. The process of compensation is done by calculating the instantaneous reactive power losses using p-q theory and the PI controller to reduce the ripple voltage of the dc capacitor of the PWM-VSI. This approach is different from conventional approach and provides very effective solution. In this simulation we use hysteresis band current controller (HCC for switching the VSI inverter. The simulation has been done for both steady state and transient conditions

  3. High-temperature optically activated GaAs power switching for aircraft digital electronic control

    Science.gov (United States)

    Berak, J. M.; Grantham, D. H.; Swindal, J. L.; Black, J. F.; Allen, L. B.

    1983-01-01

    Gallium arsenide high-temperature devices were fabricated and assembled into an optically activated pulse-width-modulated power control for a torque motor typical of the kinds used in jet engine actuators. A bipolar heterojunction phototransistor with gallium aluminum arsenide emitter/window, a gallium arsenide junction field-effect power transistor and a gallium arsenide transient protection diode were designed and fabricated. A high-temperature fiber optic/phototransistor coupling scheme was implemented. The devices assembled into the demonstrator were successfully tested at 250 C, proving the feasibility of actuator-located switching of control power using optical signals transmitted by fibers. Assessments of the efficiency and technical merits were made for extension of this high-temperature technology to local conversion of optical power to electrical power and its control at levels useful for driving actuators. Optical power sources included in the comparisons were an infrared light-emitting diode, an injection laser diode, tungsten-halogen lamps and arc lamps. Optical-to-electrical power conversion was limited to photovoltaics located at the actuator. Impedance matching of the photovoltaic array to the load was considered over the full temperature range, -55 C to 260 C. Loss of photovoltaic efficiency at higher temperatures was taken into account. Serious losses in efficiency are: (1) in the optical source and the cooling which they may require in the assumed 125 C ambient, (2) in the decreased conversion efficiency of the gallium arsenide photovoltaic at 260 C, and (3) in impedance matching. Practical systems require improvements in these areas.

  4. A Study on the Active Induction Control of Upstream Wind Turbines for total power increases

    Science.gov (United States)

    Kim, Hyungyu; Kim, Kwansoo; Paek, Insu; Bottasso, Carlo L.; Campagnolo, Filippo

    2016-09-01

    In this study, the effect of active induction control of upstream wind turbines is investigated. Two scaled wind turbines having a rotor diameter of 1 m with a spacing of four times of the rotor diameter were used to experimentally validate the concept. Also, an in-house c code was used to simulate the same two wind turbines and see if the experimental observations can be obtained. From the experiment, approximately 0.81% increase of total power could be observed. Although the simulation results were not exactly the same as the experimental results but the shape was similar and the maximum power increase of 0.27% was predicted. Also from further simulation using NREL 5MW wind turbines instead of scaled wind turbines with realistic ambient turbulence intensity, it was found that the power increase could become more than 1%.

  5. Voltage/Pitch Control for Maximization and Regulation of Active/Reactive Powers in Wind Turbines with Uncertainties

    CERN Document Server

    Guo, Yi; Jiang, John N; Tang, Choon Yik; Ramakumar, Rama G

    2010-01-01

    This paper addresses the problem of controlling a variable-speed wind turbine with a Doubly Fed Induction Generator (DFIG), modeled as an electromechanically-coupled nonlinear system with rotor voltages and blade pitch angle as its inputs, active and reactive powers as its outputs, and most of the aerodynamic and mechanical parameters as its uncertainties. Using a blend of linear and nonlinear control strategies (including feedback linearization, pole placement, uncertainty estimation, and gradient-based potential function minimization) as well as time-scale separation in the dynamics, we develop a controller that is capable of maximizing the active power in the Maximum Power Tracking (MPT) mode, regulating the active power in the Power Regulation (PR) mode, seamlessly switching between the two modes, and simultaneously adjusting the reactive power to achieve a desired power factor. The controller consists of four cascaded components, uses realistic feedback signals, and operates without knowledge of the C_p-...

  6. Active power filter for medium voltage networks with predictive current control

    Energy Technology Data Exchange (ETDEWEB)

    Verne, Santiago A.; Valla, Maria I. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata and CONICET, La Plata (Argentina)

    2010-12-15

    A transformer less Shunt Active Power Filter (SAPF) for medium voltage distribution networks based on Multilevel Diode Clamped Inverter is presented in this paper. Converter current control is based on a Model Predictive strategy, which gives very fast current response. Also, the algorithm includes voltage balancing capability which is essential for proper converter operation. The presented current control algorithm is naturally applicable to converters with an arbitrary number of levels with reduced computational effort by virtue of the incorporation of switching restrictions which are necessary for reliable converter operation. The performance of the proposed algorithm is evaluated by means of computer simulations. (author)

  7. A Simplified Control Architecture for Three-Phase Inverters in Modular UPS Application with Shunt Active Power Filter Embedded

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Vasquez, Juan Carlos

    2015-01-01

    In this paper, a simplified control architecture, including individual layer control and recover layer control, is proposed for a modular online uninterruptible power supply (UPS) system is presented. The parallel control algorithm of for the DC/AC modules are mainly concentrates on the active...... power sharing performance due to the existence of the shunt active power filter (APF). APF will deal with the reactive power brought by the nonlinear load to guarantee that all DC/AC modules are faced with a resistive type load. On the other hand, since there is no regulation on the UPS output voltage...

  8. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  9. Development of Real Time Implementation of 5/5 Rule based Fuzzy Logic Controller Shunt Active Power Filter for Power Quality Improvement

    Science.gov (United States)

    Puhan, Pratap Sekhar; Ray, Pravat Kumar; Panda, Gayadhar

    2016-12-01

    This paper presents the effectiveness of 5/5 Fuzzy rule implementation in Fuzzy Logic Controller conjunction with indirect control technique to enhance the power quality in single phase system, An indirect current controller in conjunction with Fuzzy Logic Controller is applied to the proposed shunt active power filter to estimate the peak reference current and capacitor voltage. Current Controller based pulse width modulation (CCPWM) is used to generate the switching signals of voltage source inverter. Various simulation results are presented to verify the good behaviour of the Shunt active Power Filter (SAPF) with proposed two levels Hysteresis Current Controller (HCC). For verification of Shunt Active Power Filter in real time, the proposed control algorithm has been implemented in laboratory developed setup in dSPACE platform.

  10. Minimizing the Levelized Cost of Energy in Single-Phase Photovoltaic Systems with an Absolute Active Power Control

    DEFF Research Database (Denmark)

    Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya

    2015-01-01

    Several countries with considerable PhotoVoltaic (PV) installations are facing a challenge of overloading the power infrastructure during peak-power production hours. Regulations have been imposed on the PV systems, where more active power control should be flexibly performed. As an advanced...... control strategy, the Absolute Active Power Control (AAPC) can effectively solve the overloading issues by limiting the maximum possible PV power to a certain level (i.e., the power limitation), and also benefit the inverter reliability. However, its feasibility is challenged by the energy loss....... An increase of the inverter lifetime and a reduction of the energy yield can alter the cost of energy, demanding an optimization of the power limitation. Therefore, aiming at minimizing the Levelized Cost of Energy (LCOE), the power limit is optimized for the AAPC strategy in this paper. The optimization...

  11. Current control for a shunt hybrid active power filter using recursive integral PI

    Institute of Scientific and Technical Information of China (English)

    Wei ZHAO; An LUO; Ke PENG; Xia DENG

    2009-01-01

    This paper presents a current control method for a shunt hybrid active power filter(HAPF) using recursive integral Pl algorithm.The method improves the performance of the HAPF system by reducing the influence of detection accuracy,time delay of instruction current calculation and phase displacement of output filter.Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability.The proposed algorithm is easy to implement for engineering applications and easy to compute.Experiment results have verified the validity of the proposed controller.Furthermore,the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.

  12. Active noise control of forced and induced draft fans in power generating plants

    Energy Technology Data Exchange (ETDEWEB)

    Eldada, M.V.

    1985-05-01

    A study was carried out into active noise reduction of forced draft fans in power generation plants. Active noise reduction involves detecting noise, inverting the phase and re-introducing the anti-phase signal into the duct to cancel the noise through destructive interference. Acoustic pressure transfer functions were meaured in-situ along a cross section of a 15 ft diameter fan inlet. A computer modal analysis program was written and used to analyze the field data. It was found that in frequencies between ca 5 Hz and 45 Hz the energy propagates mainly in the plane wave mode, while in higher frequencies the energy was carried mainly by higher order propagation modes. The project objective was to cancel noise up to a frequency of 130 Hz, but current technology restricted active cancellation to plane waves only. Three alternatives were considered: install a feed forward active noise control system to cancel noise at frequencies below 45 Hz; conduct research on active noise control of higher order propagation modes in ducts; or install a feed back active noise control system and a duct splitter in order to cancel noise between 30 and 130 Hz. It was recommended that the third option be selected as the next phase of the research project, which would comprise a 20 ft duct splitter and microphones, filters, amplifiers, loudspekers and cabinets. 6 refs., 12 figs.

  13. Power flow controller

    NARCIS (Netherlands)

    Ferreira, J.A.; Yuan, Z.; De Haan, S.W.H.

    2008-01-01

    The invention relates to a power flow controller, comprising at least one first converter coupled with a power transmission line, and at least one second converter coupled with a power source, wherein said power source operates at a predeter-mined first frequency and connects to the power transmissi

  14. Experimental analysis of flexibility change with different levels of power reduction by demand response activation on thermostat controlled loads

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Hu, Junjie

    2017-01-01

    This paper studies the flexibility available with thermostatically controlled loads (TCLs) to provide power system services by demand response (DR) activation. Although the DR activation on TCLs can provide power system ancillary services, it is important to know how long such services can...

  15. Application of Backstepping to the Virtual Flux Direct Power Control of Five-Level Three-Phase Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Bouzidi Mansour

    2014-03-01

    Full Text Available This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

  16. Model Predictive Controlled Active NPC Inverter for Voltage Stress Balancing Among the Semiconductor Power Switches

    Science.gov (United States)

    Parvez Akter, Md.; Dah-Chuan Lu, Dylan

    2017-07-01

    This paper presents a model predictive controlled three-level three-phase active neutral-point-clamped (ANPC) inverter for distributing the voltage stress among the semiconductor power switches as well as balancing the neutral-point voltage. The model predictive control (MPC) concept uses the discrete variables and effectively operates the ANPC inverter by avoiding any linear controller or modulation techniques. A 4.0 kW three-level three-phase ANPC inverter is developed in the MATLAB/Simulink environment to verify the effectiveness of the proposed MPC scheme. The results confirm that the proposed model predictive controlled ANPC inverter equally distributes the voltage across all the semiconductor power switches and provides lowest THD (0.99%) compared with the traditional NPC inverter. Moreover, the neutral-point voltage balancing is accurately maintained by the proposed MPC algorithm. Furthermore, this MPC concept shows the robustness capability against the parameter uncertainties of the system which is also analyzed by MATLAB/Simulink.

  17. Adaptive Control with SSNN of UPFC System for the Compensation of Active and Reactive Power

    Directory of Open Access Journals (Sweden)

    A. Bouanane

    2013-06-01

    Full Text Available The focus of this study is the effectiveness of the controller’s Unified Power Flow Controller UPFC with the choice of a control strategy. This Unified Power Flow Controller (UPFC is used to control the power flow in the transmission systems by controlling the impedance, voltage magnitude and phase angle. This controller offers advantages in terms of static and dynamic operation of the power system. It also brings in new challenges in power electronics and power system design. To evaluate the performance and robustness of the system, we proposed a hybrid control combining the concept of identification neural networks with conventional regulators and with the changes in characteristics of the transmission line in order to improve the stability of the electrical power network. With its unique capability to control simultaneously real and reactive power flows on a transmission line as well as to regulate voltage at the bus where it is connected, this device creates a tremendous quality impact on power system stability. The result which has been obtained from using MATLAB and SIMULINK software showed a good agreement with the simulation result.

  18. Simulation Research on a SVPWM Control Algorithm for a Four-Leg Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper the topology of a four-leg shunt active-power filter (APF) is given.The APF compensates harmonic and reactive power in a three-phase four-wire system.The scheme adopted for control of the four-leg active power filter, a 3-Dimensional Pulse Width Modulation (PWM) technique, is presented.The theoretical deduction of a space vector PWM (SVPWM) algorithm is given in this paper.The paper also analyzes the distribution of the voltage-space vector of the four-leg converter in αβγ coordinates and describes methods to determine the location of the voltage-space vector and to calculate duration time.Finally, the algorithm is implemented in simulation; the results show that the total harmonic distortion (THD) of the three phase-current waveforms is reduced.The neutral wire current, after compensation, is about 0 A showing that the topology of the four-leg shunt APF is feasible and the proposed scheme is effective.

  19. Wind Farm Active Power Dispatch for Output Power Maximizing Based on a Wind Turbine Control Strategy for Load Minimizing

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2015-01-01

    Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation i...

  20. A Lyapunov Stability Theory-Based Control Strategy for Three-Level Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Yijia Cao

    2017-01-01

    Full Text Available The three-phase three-wire neutral-point-clamped shunt active power filter (NPC-SAPF, which most adopts classical closed-loop feedback control methods such as proportional-integral (PI, proportional-resonant (PR and repetitive control, can only output 1st–25th harmonic currents with 10–20 kHz switching frequency. The reason for this is that the controller design must make a compromise between system stability and harmonic current compensation ability under the condition of less than 20 kHz switching frequency. To broaden the bandwidth of the compensation current, a Lyapunov stability theory-based control strategy is presented in this paper for NPC-SAPF. The proposed control law is obtained by constructing the switching function on the basis of the mathematical model and the Lyapunov candidate function, which can avoid introducing closed-loop feedback control and keep the system globally asymptotically stable. By means of the proposed method, the NPC-SAPF has compensation ability for the 1st–50th harmonic currents, the total harmonic distortion (THD and each harmonic content of grid currents satisfy the requirements of IEEE Standard 519-2014. In order to verify the superiority of the proposed control strategy, stability conditions of the proposed strategy and the representative PR controllers are compared. The simulation results in MATLAB/Simulink (MathWorks, Natick, MA, USA and the experimental results obtained on a 6.6 kVA NPC-SAPF laboratory prototype validate the proposed control strategy.

  1. An Improved Double Fuzzy PI Controller For Shunt Active Power Filter DC Bus Regulation

    Directory of Open Access Journals (Sweden)

    Nabil ELHAJ

    2015-06-01

    Full Text Available This paper targets to demonstrate the importance of the choice of the algorithm references detection to be applied with a double fuzzy PI corrector (DFPI for the control and the regulation of a shunt active power filter (SAPF DC bus voltage. In a previous work, the synchronous reference frame (SRF algorithm was applied and gave satisfactory results. In the present paper, the SRF is substituted by the positive sequence of the fundamental of the source voltage algorithm (PSF which offered better results regarding the power quality of the considered main utility feeding a variable DC RL load throughout a diode bridge. The results were carried out using computer simulation perfomed under MATLAB/Simulink environment. To make the obtained results more convenient, a comparison between the couples (SRF, PI, (PSF, PI, (SRF, DFPI, (PSF, DFPI is added to prove the effectiveness of the couple (PSF, DFPI in satisfying the compromise between a good regulation of the SAPF DC bus voltage and a good quality of filtering resulting in an improved quality of power.

  2. OTA & CCII-Based Control System of Shunt Active Power Filter Using in Three-Phase Three-wire System

    Science.gov (United States)

    Vanichprapa, Sombat; Prapanavarat, Cherdchai; Chipipop, Boonruk

    2008-10-01

    This paper presents the implementation of the OTA (Operational Transconductance Amplifier) & CCII (Second generation Current Conveyor)—based control system of active power filter (APF). The three-phase shunt PWM VSI-APF is used as the power circuit for simple control. This proposed control system using OTA & CCII-based circuits since it has the advantage of its adaptive control, real-time processing and it has wide bandwidth which can work with the high frequency power switches in order to eliminate the higher order of harmonics, moreover, it can be fabricated in one single chip by using CMOS technology. Theoretical analysis, design and simulation results are provided.

  3. Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2016-01-01

    Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

  4. Power-constrained intermittent control

    OpenAIRE

    Gawthrop, P.; Wagg, D.; Neild, S.; Wang, L

    2013-01-01

    In this article, input power, as opposed to the usual input amplitude, constraints are introduced in the context of intermittent control. They are shown to result in a combination of quadratic optimisation and quadratic constraints. The main motivation for considering input power constraints is its similarity with semi-active control. Such methods are commonly used to provide damping in mechanical systems and structures. It is shown that semi-active control can be re-expressed and generalised...

  5. Active harmonic filtering using current-controlled, grid-connected DG units with closed-loop power control

    DEFF Research Database (Denmark)

    He, Jinwei; Li, Yun Wei; Blaabjerg, Frede

    2014-01-01

    voltage detection are not necessary for the proposed harmonic compensation method. Moreover, a closed-loop power control scheme is employed to directly derive the fundamental current reference without using any phase-locked loops (PLL). The proposed power control scheme effectively eliminates the impacts...

  6. The electromechanical low-power active suspension: modeling, control, and prototype testing

    NARCIS (Netherlands)

    Evers, W.J.; Teerhuis, A.P.; Knaap, A. van der; Besselink, I.; Nijmeijer, H.

    2011-01-01

    The high energy consumption of market-ready active suspension systems is the limiting factor in the competition with semi-active devices. The variable geometry active suspension is an alternative with a significantly lower power consumption. However, previous designs suffer from packaging problems,

  7. Active and reactive power control of the doubly fed induction generator based on wind energy conversion system

    Directory of Open Access Journals (Sweden)

    Ghulam Sarwar Kaloi

    2016-11-01

    Full Text Available This paper presents a dynamic modeling and control of doubly fed induction-generator (DFIG based on the wind turbine systems. Active and reactive power control of the DFIG are based on the feedback technique by using the suitable voltage vectors on the rotor side. The rotor flux has no impact on the changes of the stator active and reactive power. The proposed controller is based on the feedback technique in order to reduce the oscillation of the generator. The control approach is estimated through the simulation result of the feedback controller assembled with DFIG wind turbines. It is applied by the feedback control based techniques in order to control the power flowing of DFIG and the power grid. Hence, an improved feedback control technique is adopted to get a better power flow transfer and to improve the dynamic system and transient stability. In stable condition, the improved performance of the controller, the proposed method is verified for the effectiveness of the control method is done in stable conditions.

  8. Dynamic Active Power Control with Improved Undead-Band Droop for HVDC Grids

    DEFF Research Database (Denmark)

    Vrana, T.K.; Zeni, Lorenzo; Fosso, O.B.

    The earlier developed control method using a piecewise linear droop curve, with different droop values for the different segments, has now been optimised for dynamic performance. Non-linearities at the junctions of two linear droop sections have been adressed. Also non-linearity of power based DC...

  9. Active Power Quality Improvement Strategy for Grid-connected Microgrid Based on Hierarchical Control

    DEFF Research Database (Denmark)

    Wei, Feng; Sun, Kai; Guan, Yajuan

    2017-01-01

    When connected to a distorted grid utility, droop-controlled grid-connected microgrids (DCGC-MG) exhibit low equivalent impedance. The harmonic and unbalanced voltage at the point of common coupling (PCC) deteriorates the power quality of the grid-connected current (GCC) of DCGC-MG. This work...

  10. Real time control of an active power filter under distorted voltage condition

    Directory of Open Access Journals (Sweden)

    Ahmed Safa

    2012-10-01

    Full Text Available

    This paper, presents three phase shunt active filter under distorted voltage condition, the active power filter control is based on the use of self-tuning filter (STF for reference current generation and on space vector PWM for generation of pulses. The dc capacitor voltage is controlled by a classical PI controller.  The diode rectifier feed RL load is taken as a nonlinear load. The self-tuning filter allows extracting directly the voltage and current fundamental components in the axis without phase locked loop (PLL under distorted voltage condition. The experiment analysis is made based on working under distorted voltage condition, and the total harmonic distortion of source current after compensation .Self tuning filter based extraction technique is good under distorted voltage conditions. The total harmonic distortion (THD of source current is fully reduced. The effectiveness of the method is theoretically studied and verified by experimentation.

  11. An Efficient Space Vector Pulse Width Modulation with BFO Based Self Tuning PI Controller for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    P. Saravanan

    2014-05-01

    Full Text Available This research study mainly focuses on using an efficient control strategy for extracting reference currents of shunt active filters under non linear load conditions. In recent decades, the utilization of highly automatic electric equipments has resulted in enormous economic loss. Thus, the power suppliers as well as the power consumers are very much concerned about the power quality issues and compensation approaches. In order to deal with this issue, Active Power Filter (APF has been considered as an attractive solution due to its significant harmonic compensation. But, the performance of APF is not consistent and is varies based on the output of the controller techniques. An efficient (id-id control strategy is used in this approach for attaining utmost profit from grid-interfacing inverters installed in transmission systems. The voltages are controlled through the PI controller which is further tuned by an optimization approach. Bacterial Forge Optimization (BFO is used in this approach for tuning the PI controller for the optimal value. The inverter used in this approach can be considered as a Shunt Active Power Filter (SAPF to compensate non linear load current harmonics. In order to improve the overall performance of the system, Space Vector Pulse Width Modulation (SVPWM is used in this proposed approach which regulates power frequency and produces good circularity through DC-AC part. SVPWM also eliminates the 3rd order harmonics and minimizes the 5th order harmonics effectively. The integration of (id-id control strategy and SVPWM has been proposed in this research study. Simulation results are carried out in MATLAB/Simulink and the performance of the proposed approach is compared with other control strategies. This research studies shows unique approach for attaining maximum benefits from RES with suppression of current harmonics.

  12. Mitigation of Wind Power Fluctuation by Active Current Control of Variable Speed Wind Turbines

    DEFF Research Database (Denmark)

    Zhang, Yunqian; Chen, Zhe; Hu, Weihao

    2013-01-01

    Wind shear and tower shadow are the sources of power fluctuation of grid connected wind turbines during continuous operation. This paper presents a simulation model of a MW-level doubly fed induction generator (DFIG) based variable speed wind turbine with a partial-scale back-to-back power conver...... of the wind turbine. The simulations are performed on the NREL 1.5MW upwind reference wind turbine model. The simulation results are presented and discussed to demonstrate the validity of the proposed control method....

  13. Active power control with undead-band voltage & frequency droop applied to a meshed DC grid test system

    DEFF Research Database (Denmark)

    Vrana, Til Kristian; Zeni, Lorenzo; Fosso, Olav Bjarte

    2012-01-01

    A new method for controlling active power in HVDC grids has been tested on the meshed CIGRE B4 DC grid test system. The control strategy is based on the recently proposed undead-band droop control, which combines DC voltage and AC frequency droop. It provides sufficient roomm for optimisation...... for both normal and disturbed operation. Its main features are flexibility, reliability due to distributed control, easy expandability of the system and minimisation of communication needs. The control technique has been tested and its effectiveness has been verified to demonstrate its suitability...

  14. Active Power Control with Undead-Band Voltage & Frequency Droop for HVDC Converters in Large Meshed DC Grids

    DEFF Research Database (Denmark)

    Vrana, Til Kristian; Zeni, Lorenzo; Fosso, Olav Bjarte

    A new control method for large meshed HVDC grids has been developed, which helps to keep the active power balance at the AC and the DC side. The method definition is kept wide, leaving the possibility for control parameter optimisation. Other known control methods can be seen as specific examples...... the band, but not set to zero as with a regular dead-band. It operates with a minimum of required communication. New converters can be added to the system without changing the control of the other individual converters. It is well suited to achieve high reliability standards due to the distributed control...

  15. Analysis and Sliding Mode Control of Four-Wire Three-Leg Shunt Active Power Filter

    OpenAIRE

    Farid Hamoudi; Hocine Amimeur

    2015-01-01

    In this paper, the analysis and the sliding mode control application for a shunt active filter is presented. The active filter is based on a three-leg split-capacitor voltage source inverter which is used to compensate harmonics and unbalance in the phase currents, and therefore to cancel neutral current. The proposed sliding mode control is formulated from the multivariable state model established in dq0 frames. The selection of the sliding mode functions takes in account simultaneously, the...

  16. Development of Flexible Active Power Control Strategies for Grid-Connected Photovoltaic Inverters by Modifying MPPT Algorithms

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    As the penetration level of grid-connected PV systems increases, more advanced control functionality is demanded. In order to ensure smooth and friendly grid integration as well as enable more PV installations, the power generated by PV systems needs to be flexible and capable of: 1) limiting...... strategies for grid-connected PV inverters by modifying maximum power point tracking algorithms, where the PV power is regulated by changing the operating point of the PV system. In this way, no extra equipment is needed, being a cost-effective solution. Experiments on a 3-kW grid-connected PV system have...... been performed, where the developed flexible active power control functionalities are achieved per demands....

  17. DQ reference frame modeling and control of single-phase active power decoupling circuits

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2015-01-01

    . This paper presents the dq synchronous reference frame modeling of single-phase power decoupling circuits and a complete model describing the dynamics of dc-link ripple voltage is presented. The proposed model is universal and valid for both inductive and capacitive decoupling circuits, and the input...... of decoupling circuits can be either dependent or independent of its front-end converters. Based on this model, a dq synchronous reference frame controller is designed which allows the decoupling circuit to operate in two different modes because of the circuit symmetry. Simulation and experimental results...... are presented to verify the effectiveness of the proposed modeling and control method....

  18. Thermionic power system power processing and control

    Science.gov (United States)

    Metcalf, Kenneth J.

    1992-01-01

    Thermionic power systems are being considered for space-based miltary applications because of their survivability and high efficiency. Under the direction of the Air Force, conceptual designs were generated for two thermionic power systems to determine preliminary system performance data and direct future component development. This paper discusses the power processing and control (PP&C) subsystem that conditions the thermionic converter power and controls the operation of the reactor and thermionic converter subsystems. The baseline PP&C design and design options are discussed, mass and performance data are provided, and technology needs are identified. The impact on PP&C subsystem mass and efficiency of alternate power levels and boom lengths is also presented. The baseline PP&C subsystem is lightweight and reliable, and it uses proven design concepts to minimize development and testing time. However, the radiation dosages specified in the program research and development announcement (PRDA) are 10 to 100 times the capabilities of present semiconductor devices. While these levels are aggressive, they are considered to be achievable by 1995 if the Air Force and other government agencies continue to actively develop radiation resistant electronics devices for military applications.

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

    Science.gov (United States)

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

    2008-12-16

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

  1. Frequency control in power systems with high wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tarnowski, German Claudio [Technical Univ. of Denmark (Denmark). Centre for Electric Technology; Vestas Wind Systems A/S, Alsve (Denmark); Kjaer, Philip Carne [Vestas Wind Systems A/S, Alsve (Denmark); Oestergaard, Jacob [Technical Univ. of Denmark (Denmark). Centre for Electric Technology; Soerensen, Poul E. [Risoe National Laboratory for Sustainable Energy, Roskilde (Denmark). Wind Energy Dept.

    2010-07-01

    The fluctuating nature of wind power introduces several challenges to reliable operation of power system. With high wind power penetration, conventional power plants are displaced and wind speed fluctuations introduce large power imbalances which lead to power system frequency control and operational problems. This paper analysis the impact of wind power in the frequency control of power systems for different amount of controllable variable speed wind turbines. Real measurements from short term wind power penetration tests in a power system are shown and used to study the amount of total regulating power needed from conventional power plants. Dynamic simulations with validated model of the power system support the studies. The paper also presents control concepts for wind power plants necessary to achieve characteristic of frequency response and active power balancing similarly to conventional power plants, therefore allowing higher wind power penetration. As the power system dependency on wind power increases, wind power generation has to contribute with dynamic response and control actions similarly to conventional power plants. (orig.)

  2. Oilwell Power Controller (OPC)

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Oil Well Power Controller (OPC) prototype units is nearing completion. This device is an oilwell beam pump controller and data logger. Applications for this device have been for an electrical power saving device, pump off control, parafffin detection, demand power load control, chemical treatment data, dynamometer and pump efficiency data. Preliminary results appear vary promising. A total of ten OPC rod pump controllers were assembled and installed on oilwells in several areas of Central and Western United States. Data was analyzed on these wells and forwarded to the participating oil companies. Cost savings on each individual oil well participating in the OPC testing vary considerably, savings on some situations have been outstanding. In situations where the pump efficiency was determined to be low, the cost savings have been considerable. Cost savings due to preventive maintenance are also present, but are difficult to pin point an exact dollar amount at the present time. A break out of actual cost data obtained on some of the oilwells controlled and monitored with the oilwell power controller.

  3. Evaluation of a Trapezoidal Predictive Controller for a Four-Wire Active Power Filter for Utility Equipment of Metro Railway, Power-Land Substations

    Directory of Open Access Journals (Sweden)

    Sergio Salas-Duarte

    2016-01-01

    Full Text Available The realization of an improved predictive current controller based on a trapezoidal model is described, and the impact of this technique is assessed on the performance of a 2 kW, 21.6 kHz, four-wire, Active Power Filter for utility equipment of Metro Railway, Power-Land Substations. The operation of the trapezoidal predictive current controller is contrasted with that of a typical predictive control technique, based on a single Euler approximation, which has demonstrated generation of high-quality line currents, each using a 400 V DC link to improve the power quality of an unbalanced nonlinear load of Metro Railway. The results show that the supply current waveforms become virtually sinusoidal waves, reducing the current ripple by 50% and improving its power factor from 0.8 to 0.989 when the active filter is operated with a 1.6 kW load. The principle of operation of the trapezoidal predictive controller is analysed together with a description of its practical development, showing experimental results obtained with a 2 kW prototype.

  4. Power, control and optimization

    CERN Document Server

    Vasant, Pandian; Barsoum, Nader

    2013-01-01

    The book consists of chapters based on selected papers of international conference „Power, Control and Optimization 2012”, held in Las Vegas, USA. Readers can find interesting chapters discussing various topics from the field of power control, its distribution and related fields. Book discusses topics like energy consumption impacted by climate, mathematical modeling of the influence of thermal power plant on the aquatic environment, investigation of cost reduction in residential electricity bill using electric vehicle at peak times or allocation and size evaluation of distributed generation using ANN model and others.  Chapter authors are to the best of our knowledge the originators or closely related to the originators of presented ideas and its applications. Hence, this book certainly is one of the few books discussing the benefit from intersection of those modern and fruitful scientific fields of research with very tight and deep impact on real life and industry. This book is devoted to the studies o...

  5. Control of power sourced from a microbial fuel cell reduces its start-up time and increases bioelectrochemical activity.

    Science.gov (United States)

    Boghani, Hitesh C; Kim, Jung Rae; Dinsdale, Richard M; Guwy, Alan J; Premier, Giuliano C

    2013-07-01

    Microbial fuel cell (MFC) performance depends on the selective development of an electrogenic biofilm at an electrode. Controlled biofilm enrichment may reduce start-up time and improve subsequent power performance. The anode potential is known to affect start-up and subsequent performance in electrogenic bio-catalytic consortia. Control strategies varying electrical load through gradient based maximum power point tracking (MPPT) and transient poised anode potential followed by MPPT are compared to static ohmic loading. Three replicate H-type MFCs were used to investigate start-up strategies: (1) application of an MPPT algorithm preceded by poised-potential at the anode (+0.645 V vs Ag/AgCl); (2) MFC connected to MPPT-only; (3) static external load of 1 kΩ and 500 Ω. Active control showed a significant reduction in start-up time from 42 to 22 days, along with 3.5-fold increase in biocatalytic activity after start-up. Such active control may improve applicability by accelerating start-up and enhancing MFC power and bio-catalytic performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Optimal Power Flow Control by Rotary Power Flow Controller

    Directory of Open Access Journals (Sweden)

    KAZEMI, A.

    2011-05-01

    Full Text Available This paper presents a new power flow model for rotary power flow controller (RPFC. RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST and two conventional (series and shunt transformers. Structurally, an RPST consists of two windings (stator and rotor windings. The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.

  7. The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiquan [Stanford Univ., CA (United States)

    2008-12-01

    In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

  8. Indirect Control and Power

    Directory of Open Access Journals (Sweden)

    Cesarino Bertini

    2016-01-01

    Full Text Available To determine who has the power within a stock corporate company can be a quite complex problem, especially when control is achieved through alliances between shareholders. This problem arises especially in cases of indirect control of corporations, that is, in situations involving shareholders and companies with cross-shareholdings. The first to solve the problem of measuring power in the case of indirect share control were Gianfranco Gambarelli and Guillermo Owen in [10]. In the following years, numerous other models were introduced. In this paper, we critically examine the models of: Gambarelli and Owen, Denti and Prati, Crama and Leruth, Karos and Peters, as well as Mercik and Lobos, taking into account two well-known, illustrative examples, one with an acyclic corporate structure and the other with a cyclic structure. (original abstract

  9. Control of current inverters in decentral power systems as active filters; Regelung von Netzstromrichtern in dezentralen Energiesystemen als aktive Filter

    Energy Technology Data Exchange (ETDEWEB)

    Merfert, Igor; Lindemann, Andreas [Magdeburg Univ. (Germany). Lehrstuhl fuer Leistungselektronik

    2007-07-01

    Besides their main task, decentralized power generators can combine electric power generation with system services if the inverter has current capability to spare. This paper deals with the system services, power quality improvement and a reactive power compensation, in a fuel cell based decentralized electrical power generator. A control strategy and a practical realization are introduced. (orig.)

  10. Secondary Path Modeling Method for Active Noise Control of Power Transformer

    Science.gov (United States)

    Zhao, Tong; Liang, Jiabi; Liang, Yuanbin; Wang, Lixin; Pei, Xiugao; Li, Peng

    The accuracy of the secondary path modeling is critical to the stability of active noise control system. On condition of knowing the input and output of the secondary path, system identification theory can be used to identify the path. Based on the experiment data, correlation analysis is adopted to eliminate the random noise and nonlinear harmonic in the output data in order to obtain the accurate frequency characteristic of the secondary path. After that, Levy's Method is applied to identify the transfer function of the path. Computer simulation results are given respectively, both showing the proposed off-line modeling method is feasible and applicable. At last, Levy's Method is used to attain an accurate secondary path model in the active control of transformer noise experiment and achieves to make the noise sound level decrease about 10dB.

  11. Active structural acoustic control of noise from power transformers; Aktive Laermdaemmung von Leistungstransformatoren mit Gegenlaerm

    Energy Technology Data Exchange (ETDEWEB)

    Brungardt, K.; Vierengel, J.; Weissmann, K. [Quiet Power Systems Inc., New York, NY (United States); Schemel, G.; Lorin, P. [ABB Secheron SA, Genf (Switzerland)

    1998-04-06

    Population growth and tougher zoning regulations mean transformer noise is a growing problem for electric utilities. Transformer noise is dominanted by low frequency tones which are difficult to control by passive means, but are effectively attenuated by active noise control. This paper details a novel noise control system that actively attenuates transformer noise using a combination of structural actuators mounted on the radiating surface of the transformer tank, and specially designed resonant acoustic devices located just off the tank surface. An adaptive selfcalibrating, multi-channel controller is used to automatically respond to changes in noise level during transformer operation. Performance results have been proven at a number of field installations in utility substations, and an installation case study is provided here as an example. (orig.) [Deutsch] Beim Betrieb von Leistungstransformatoren entstehen Geraeusche, die besonders in der Naehe von Wohngebieten als stoerend empfunden werden. Zunehmend strengere Laermschutzverordnungen erfordern daher Massnahmen um die Geraeuschentwicklung von Transformatoren zu reduzieren. Die passive Daempfung dieses `Brummens` durch Bauten ist oft mit hohen Kosten verbunden und bereitet Schwierigkeiten bei der Umsetzung. Fuer Abhilfe sorgt ein neuartiges System, das den Transformatorenlaerm aktiv daempft. Dabei setzt man zur Reduktion des Transformatorenlaerms neuartige, durch adaptive Algorythmen gesteuerte Aktuatoren ein, die den stoerenden Laerm direkt am Transformator selbst daempfen. (orig.)

  12. Stirling engine power control

    Science.gov (United States)

    Fraser, James P.

    1983-01-01

    A power control method and apparatus for a Stirling engine including a valved duct connected to the junction of the regenerator and the cooler and running to a bypass chamber connected between the heater and the cylinder. An oscillating zone of demarcation between the hot and cold portions of the working gas is established in the bypass chamber, and the engine pistons and cylinders can run cold.

  13. Active Power and Flux Control of a Self-Excited Induction Generator for a Variable-Speed Wind Turbine Generation

    Energy Technology Data Exchange (ETDEWEB)

    Na, Woonki; Muljadi, Eduard; Leighty, Bill; Kim, Jonghoon

    2017-05-11

    A Self-Excited Induction Generation (SEIG) for a variable speed wind turbine generation(VS-WG) is normally considered to be a good candidate for implementation in stand-alone applications such as battery charging, hydrogenation, water pumping, water purification, water desalination, and etc. In this study, we have examined a study on active power and flux control strategies for a SEIG for a variable speed wind turbine generation. The control analysis for the proposed system is carried out by using PSCAD software. In the process, we can optimize the control design of the system, thereby enhancing and expediting the control design procedure for this application. With this study, this control design for a SEIG for VS-WG can become the industry standard for analysis and development in terms of SEIG.

  14. Active Power Dispatch Method for a Wind Farm Central Controller Considering Wake Effect

    DEFF Research Database (Denmark)

    Tian, Jie; Su, Chi; N. Soltani, Mohsen

    2014-01-01

    ), then dispatch the wind power reference to each wind turbine. One of the most commonly used dispatch methods is to dispatch the wind power reference to each wind turbine proportional to each wind turbine’s available wind power without the consideration of the wake effect. The wake which depends on the thrust...... Optimization (PSO) is used to obtain the optimal wind power for each wind turbine. A case study is carried out. The available wind power of the wind farm was compared between the traditional dispatch method and the proposed dispatch method with the consideration of the wake effect....

  15. Adaptive Hybrid Fuzzy-Proportional Plus Crisp-Integral Current Control Algorithm for Shunt Active Power Filter Operation

    Directory of Open Access Journals (Sweden)

    Nor Farahaida Abdul Rahman

    2016-09-01

    Full Text Available An adaptive hybrid fuzzy-proportional plus crisp-integral current control algorithm (CCA for regulating supply current and enhancing the operation of a shunt active power filter (SAPF is presented. It introduces a unique integration of fuzzy-proportional (Fuzzy-P and crisp-integral (Crisp-I current controllers. The Fuzzy-P current controller is developed to perform gain tuning procedure and proportional control action. This controller inherits the simplest configuration; it is constructed using a single-input single-output fuzzy rule configuration. Thus, an execution of few fuzzy rules is sufficient for the controller’s operation. Furthermore, the fuzzy rule is developed using the relationship of currents only. Hence, it simplifies the controller development. Meanwhile, the Crisp-I current controller is developed to perform integral control action using a controllable gain value; to improve the steady-state control mechanism. The gain value is modified and controlled using the Fuzzy-P current controller’s output variable. Therefore, the gain value will continuously be adjusted at every sample period (or throughout the SAPF operation. The effectiveness of the proposed CCA in regulating supply current is validated in both simulation and experimental work. All results have proven that the SAPF using the proposed CCA is capable to regulate supply current during steady-state and dynamic-state operations. At the same time, the SAPF is able to enhance its operation in compensating harmonic currents and reactive power. Furthermore, the implementation of the proposed CCA has resulted more stable dc-link voltage waveform.

  16. Active control of radiated sound power from a baffled, rectangular panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1996-01-01

    with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over...

  17. Power considerations for trials of two experimental arms versus a standard active control or placebo.

    Science.gov (United States)

    Hasselblad, Vic

    2016-10-01

    The power of the two-experimental arm trial depends on three choices: (1) when one arm is dropped (if at all); (2) the final testing procedure, assuming no dropping; and (3) the sampling ratio for the three arms. Multiple-arm designs require critical values which were calculated using Mathematica. Power calculations were exact based on probabilities from binomial distributions. The "drop the loser" strategy is optimal for the primary endpoint. The equal sized two treated arm trial gives reasonable power for the primary as well as good power to select the best treated arm. The best power was provided by the 3:3:4 sampling, but it was only marginally better.

  18. Power flow control schemes for series-connected FACTS controllers

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Yang; Kazerani, Mehrdad [University of Waterloo, Department of Electrical & amp; Computer Engineering, Waterloo, Ont. (Canada N2L 3G1)

    2006-06-15

    Unified power flow controller (UPFC) and interline power flow controller (IPFC) are FACTS devices that can control the power flow in transmission lines by injecting active and reactive voltage components in series with the lines, using power converter modules, based on an externally regulated dc-link voltage. One key issue, in this application, is to find a relationship between the injected voltage and the resulting power flow in the line. In this paper, this relationship is derived analytically, and used to design two power flow control schemes. The proposed control schemes are applicable to any series-connected FACTS controller with the capability of producing a controllable voltage. In this paper, the proposed power flow control schemes are applied to a voltage-sourced converter-based IPFC, and the resulting control performances are examined using PSCAD/EMTDC simulation package. The simulation results show the effectiveness of the proposed power flow control schemes. (author)

  19. Power efficiency of the active boundary layer control around the hump by a slotted synthetic jet generator

    Directory of Open Access Journals (Sweden)

    Pick Petr

    2015-01-01

    Full Text Available The present contribution summarizes the power efficiency of the active flow control of the boundary layer of air around a hump. The synthetic jet generator with a rectangular output part, i.e. a slot, is actuated using a modulated signal. The actuation of the synthetic jet is carried out by modulating the input voltage of acoustic transducers of the generator. This causes the decrease of the loss coefficient and the change of the mixing size area (e.g. wake. A comparison of three types of modulating signals and their influence on the loss coefficient is performed. The main advantages of modulated signal are then described.

  20. Power System Harmonic Compensation Using Shunt Active Power Filter.

    Directory of Open Access Journals (Sweden)

    Shiuly Mukherjee

    2014-07-01

    Full Text Available This paper shows the method of improving the power quality using shunt active power filter. The proposedtopic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is fromhysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Thispaper represents the simulation and analysis of the using three phase three wire system active filter to compensate harmonics .Theproposed shunt active filter model uses balanced non-linear load. This paper successfully lowers the THD within IEEE norms and satisfactorily works to compensatecurrent harmonics.

  1. Power performance optimization and loads alleviation with active flaps using individual flap control

    Science.gov (United States)

    Pettas, Vasilis; Barlas, Thanasis; Gertz, Drew; Madsen, Helge A.

    2016-09-01

    The present article investigates the potential of Active Trailing Edge Flaps (ATEF) in terms of increase in annual energy production (AEP) as well as reduction of fatigue loads. The basis for this study is the DTU 10 MW Reference Wind Turbine (RWT) simulated using the aeroelastic code HAWC2. In an industrial-oriented manner the baseline rotor is upscaled by 5% and the ATEFs are implemented in the outer 30% of the blades. The flap system is kept simple and robust with a single flap section and control with wind speed, rotor azimuth, root bending moments and angle of attack in flap's mid-section being the sensor inputs. The AEP is increased due to the upscaling but also further due to the flap system while the fatigue loads in components of interest (blade, tower, nacelle and main bearing) are reduced close to the level of the original turbine. The aim of this study is to demonstrate a simple and applicable method that can be a technology enabler for rotor upscaling and lowering cost of energy.

  2. Design and Analysis of Sliding Mode Controller and Simplified Space Vector Modulation for Three Phase Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    S. Elangovan

    2014-07-01

    Full Text Available The main aim of this study is to control a multivariable coupled system by choosing sliding mode switching function. A Sliding mode control approach is developed to control a three phase three wire voltage source inverter operating as a shunt active power filter. Hence, no need to divide the system model developed in the synchronous ‘dq’ reference frame into two separate loops. Furthermore, the proposed control strategy allows a better stability and robustness over a wide range of operation. When sine PWM is used for generation of pulses for the switches, a variable switching nature is exhibited. The pulses for the active filter are fed by a Space Vector Modulation in order to have a constant switching of converter switches. But, the conventional space vector modulation, if implemented practically, needs a complicated algorithm which uses the trigonometric functions such as arctan, Sine and Cosine functions which in turn needs look up tables to store the pre-calculated trigonometric values. In this study, a very simplified algorithm is proposed for generating Space vector modulated pulse for all six switches without the use of look up tables and only by sensing the voltages and currents of the voltage source inverter acting as shunt active filter. The simulation using PSIM and MATLAB software verifies the results very well.

  3. High Performance Current Controller for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, Cristian; Asiminoaei, Lucian; Boldea, I.;

    2007-01-01

    computational effort. The proposed controller design is based on the pole-zero cancellation technique, taking into account the load transfer function at each harmonic frequency. Two design methods are provided, which give controller transfer functions with superior frequency response. The complete current...... controller is realized as the superposition of all individual harmonic controllers. The frequency response of the entire closed loop control is optimal with respect to filtering objectives, i.e., the system provides good overall stability and excellent selectivity for interesting harmonics. This conclusion...

  4. Application of Model Predictive Control for Active Load Management in a Distributed Power System with High Wind Penetration

    DEFF Research Database (Denmark)

    Zong, Yi; Kullmann, Daniel; Thavlov, Anders

    2012-01-01

    management. It also presents in detail how to implement a thermal model predictive controller (MPC) for the heaters' power consumption prediction in the PowerFlexHouse. It demonstrates that this MPC strategy can realize load shifting, and using good predictions in MPC-based control, a better matching...

  5. Active control for power flow of a Timoshenko beam%Timoshenko梁功率流主动控制研究

    Institute of Scientific and Technical Information of China (English)

    王有懿; 马文来; 赵阳

    2013-01-01

    To study dynamic response and active control of a beam structure under influences of disturbance, firstly, based on Timoshenko beam theory, the dynamic model of a cantilever beam was established with the travelling wave method and its accurate dynamic response was obtained, then the power flow transmission of the structure was determined. The power flow was taken as an objective function, and the optimized control force amplitude and phase were gained with an optimization algorithm, the optimal control force was applied to the beam structure. Ultimately, the active control for the power flow of Timoshenko beam structure was realized. The numerical simulation of the dynamic response and the active control for the power flow of Timoshenko beam structure was made and the results were compared with those of the Euler-Bernoulli beam theory. The results showed that the dynamic response of the beam structure with the travelling wave method is accurate and reliable; Timoshenko beam model is more accurate than Euler-Bernoulli beam model in a mid-high frequency range, and is closer to practical engineering; the correctness and effectiveness of the active control method of power flow with the travelling wave method are verified, and this method can efficiently reduce jitters of beam structures in the whole frequency domain.%为研究扰动影响下梁式结构动力学响应与主动控制,基于Timoshenko梁理论,采用行波方法建立悬臂梁结构的动力学模型并获得扰动下的精确动力学响应及结构中传播的功率流.以此为目标函数,优化得到最优控制力大小与相位.对结构施加最优控制力,实现Timoshenko梁结构的功率流主动控制.对Timoshenko梁结构动力学响应与功率流主动控制方法进行数值计算,并与Euler-Bernoulli梁理论结果进行对比分析.结果表明,采用行波方法计算梁结构动力学响应准确可靠;Timoshenko梁模型较Euler-Bernoulli梁模型在中、高频段更精确,更

  6. ANN based controller for three phase four leg shunt active filter for power quality improvement

    Directory of Open Access Journals (Sweden)

    J. Jayachandran

    2016-03-01

    Full Text Available In this paper, an artificial neural network (ANN based one cycle control (OCC strategy is proposed for the DSTATCOM shunted across the load in three phase four wire distribution system. The proposed control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage and compensates neutral current under varying source and load conditions. The proposed control strategy is superior over conventional methods as it eliminates, the sensors needed for sensing load current and coupling inductor current, in addition to the multipliers and the calculation of reference currents. ANN controllers are implemented to maintain voltage across the capacitor and as a compensator to compensate neutral current. The DSTATCOM performance is validated for all possible conditions of source and load by simulation using MATLAB software and simulation results prove the efficacy of the proposed control over conventional control strategy.

  7. Review of Active and Reactive Power Sharing Strategies in Hierarchical Controlled Microgrids

    DEFF Research Database (Denmark)

    Han, Yang; Li, Hong; Shen, Pan

    2017-01-01

    Microgrids consist of multiple parallel-connected distributed generation (DG) units with coordinated control strategies, which are able to operate in both grid-connected and islanded mode. Microgrids are attracting more and more attention since they can alleviate the stress of main transmission...... strategies are utilized as supplements of the conventional droop controls and virtual impedance methods. The improved hierarchical control approaches such as the algorithms based on graph theory, multi-agent system, the gain scheduling method and predictive control have been proposed to achieve proper...

  8. New controllability criteria for 3-phase 4-wire inverters applied to shunt active power filters

    OpenAIRE

    Perales Esteve, Manuel Ángel; Sánchez Segura, Juan Antonio; Torre, A. (Alberto) de la; Carrasco Solís, Juan Manuel; García Franquelo, Leopoldo; Terrón, L.

    2002-01-01

    In shunt active filter applications, the 3-phase 4-wire topology is frequently used when dealing with unbalanced loads containing zero sequence components. A new design criteria for this topology is presented, based on the well-known existing method for the 3-phase 3-wire system. Simulation and experimental results confirms the validity of this new criteria, providing an easy method for the design of the reactive elements involved in a shunt active filter.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  10. Power performance optimization and loads alleviation with active flaps using individual flap control

    DEFF Research Database (Denmark)

    Pettas, Vasilis; Barlas, Athanasios; Gertz, Drew Patrick;

    2016-01-01

    The present article investigates the potential of Active Trailing Edge Flaps (ATEF) in terms of increase in annual energy production (AEP) as well as reduction of fatigue loads. The basis for this study is the DTU 10 MW Reference Wind Turbine (RWT) simulated using the aeroelastic code HAWC2...... the sensor inputs. The AEP is increased due to the upscaling but also further due to the flap system while the fatigue loads in components of interest (blade, tower, nacelle and main bearing) are reduced close to the level of the original turbine. The aim of this study is to demonstrate a simple...

  11. Automated power management and control

    Science.gov (United States)

    Dolce, James L.

    1991-01-01

    A comprehensive automation design is being developed for Space Station Freedom's electric power system. A joint effort between NASA's Office of Aeronautics and Exploration Technology and NASA's Office of Space Station Freedom, it strives to increase station productivity by applying expert systems and conventional algorithms to automate power system operation. The initial station operation will use ground-based dispatches to perform the necessary command and control tasks. These tasks constitute planning and decision-making activities that strive to eliminate unplanned outages. We perceive an opportunity to help these dispatchers make fast and consistent on-line decisions by automating three key tasks: failure detection and diagnosis, resource scheduling, and security analysis. Expert systems will be used for the diagnostics and for the security analysis; conventional algorithms will be used for the resource scheduling.

  12. Power-control switch

    Science.gov (United States)

    Kessler, L. L.

    1976-01-01

    Constant-current source creates drive current independent of input-voltage variations, 50% reduction in power loss in base drive circuitry, maintains essentially constant charge rate, and improves rise-time consistency over input voltage range.

  13. Different Predictive Control Strategies for Active Load Management in Distributed Power Systems with High Penetration of Renewable Energy Sources

    DEFF Research Database (Denmark)

    Zong, Yi; Bindner, Henrik W.; Gehrke, Oliver

    2013-01-01

    is built around a small power grid with renewable power generations (two wind turbines and solar panels), a vanadium battery for storage, EV-charging infrastructure for EVs, and an intelligent office building. The simulation and field tests demonstrated that GA-based and MPC-based predictive control......In order to achieve a Danish energy supply based on 100% renewable energy from combinations of wind, biomass, wave and solar power in 2050 and to cover 50% of the Danish electricity consumption by wind power in 2020, it requires more renewable energy in buildings and industries (e.g. cold stores...

  14. Microprocessor control for standardized power control systems

    Science.gov (United States)

    Green, D. G.; Perry, E.

    1978-01-01

    The use of microcomputers in space-oriented power systems as a replacement for existing inflexible analog type controllers has been proposed. This study examines multiprocessor systems, various modularity concepts and presents a conceptualized power system incorporating a multiprocessor controller as well as preliminary results from a breadboard model of the proposed system.

  15. Robust power system frequency control

    CERN Document Server

    Bevrani, Hassan

    2008-01-01

    Emphasizes the physical and engineering aspects of the power system frequency control design problem while providing a conceptual understanding of frequency regulation and application of robust control techniques. This book summarizes the author's research outcomes, contributions and experiences with power system frequency regulation.

  16. DSP controlled power converter

    OpenAIRE

    Chan, CH; Pong, MH

    1995-01-01

    A digital controller is designed and implemented by a Digital Signal Processor (DSP) to replace the Pulse Width Modulator (PWM) and error amplifier compensation network in a two wheeler forward converter. The DSP controller is designed in three approaches: a) Discretization of analog controller - the design is based on the transfer function of the error amplifier compensation network. b) Digital PID controller design - the design is based on the general form of the pulse transfer function of ...

  17. Power generation, operation, and control

    CERN Document Server

    Wood, Allen J

    2012-01-01

    A comprehensive text on the operation and control of power generation and transmission systems In the ten years since Allen J. Wood and Bruce F. Wollenberg presented their comprehensive introduction to the engineering and economic factors involved in operating and controlling power generation systems in electric utilities, the electric power industry has undergone unprecedented change. Deregulation, open access to transmission systems, and the birth of independent power producers have altered the structure of the industry, while technological advances have created a host of new opportunities

  18. Control of a three-phase four-wire shunt-active power filter based on DC-bus energy regulation

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro;

    2008-01-01

    stored in the DC bus and active power requirements on the APF. Harmonics and imbalances both on the utility voltage and load current have been considered and the power developed by the active power filter has been evaluated. This study allows designing a controller for the APF based on the regulation...... of the energy-state of its DC-bus. The method has been experimentally tested on a four leg APF based on a neutral-point-clamped DC bus. Such topology allowed the test of the most general case, including harmonics and imbalance in utility voltage and in load currents....

  19. Different Predictive Control Strategies for Active Load Management in Distributed Power Systems with High Penetration of Renewable Energy Sources

    DEFF Research Database (Denmark)

    Zong, Yi; Bindner, Henrik W.; Gehrke, Oliver

    2013-01-01

    In order to achieve a Danish energy supply based on 100% renewable energy from combinations of wind, biomass, wave and solar power in 2050 and to cover 50% of the Danish electricity consumption by wind power in 2020, it requires more renewable energy in buildings and industries (e.g. cold stores,...... of renewable energy sources, which could lead to reducing reinforcements in the future power systems.......In order to achieve a Danish energy supply based on 100% renewable energy from combinations of wind, biomass, wave and solar power in 2050 and to cover 50% of the Danish electricity consumption by wind power in 2020, it requires more renewable energy in buildings and industries (e.g. cold stores...... and residential sectors, based on dynamic power price and weather forecast, considering users’ comfort settings to meet an optimization objective, such as maximum profit or minimum energy consumption. Some field tests were carried out on a facility for intelligent, active and distributed power systems, which...

  20. An Enhanced Dual Droop Control Scheme for Resilient Active Power Sharing among Paralleled Two-Stage Converters

    DEFF Research Database (Denmark)

    Liu, Hongpeng; Yang, Yongheng; Wang, Xiongfei;

    2017-01-01

    Traditional droop-controlled system has assumed that generators can always generate the powers demanded from them. This is true with conventional sources, where fuel supplies are usually planned in advance. For renewable sources, it may also be possible if energy storage is available. Energy stor...

  1. Real-Time Control of Shunt Active Power Filter under Distorted Grid Voltage and Unbalanced Load Condition Using Self Tuning Filter

    OpenAIRE

    2014-01-01

    In this paper, an alternative control method is proposed to improve the harmonic suppression efficiency of the active power filter in a distorted and an unbalanced power system to compensate for the perturbations caused by the unbalanced non-linear loads. The proposed method uses a self-tuning filter (STF) to process the grid voltage in order to provide a uniform reference voltage to obtain the correct angular position of the phase locked loop. Moreover, the required compensation currents are...

  2. A new high-performance AC/DC power factor correction switching converter based on one-cycle control technology and active floating-charge technology

    Institute of Scientific and Technical Information of China (English)

    GAO Chao

    2008-01-01

    A new family of converters, high-performance AC/DC power factor correction (PFC) switching converters with one-cycle control technology and active floating-charge technology, was derived and experimentally verified. The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed. Its operating prniciples and control methods were expounded. Based on these, a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein. The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.

  3. Digital control in power electronics

    CERN Document Server

    Buso, Simone

    2015-01-01

    This book presents the reader, whether an electrical engineering student in power electronics or a design engineer, a selection of power converter control problems and their basic digital solutions, based on the most widespread digital control techniques. The presentation is primarily focused on different applications of the same power converter topology, the half-bridge voltage source inverter, considered both in its single- and three-phase implementation. This is chosen as the test case because, besides being simple and well known, it allows the discussion of a significant spectrum of the mo

  4. Bidirectional power converter control electronics

    Science.gov (United States)

    Mildice, J. W.

    1987-01-01

    The object of this program was to design, build, test, and deliver a set of control electronics suitable for control of bidirectional resonant power processing equipment of the direct output type. The program is described, including the technical background, and results discussed. Even though the initial program tested only the logic outputs, the hardware was subsequently tested with high-power breadboard equipment, and in the testbed of NASA contract NAS3-24399. The completed equipment is now operating as part of the Space Station Power System Test Facility at NASA Lewis Research Center.

  5. Power optimized programmable embedded controller

    CERN Document Server

    Kamaraju, M; Tilak, A V N; 10.5121/ijcnc.2010.2409

    2010-01-01

    Now a days, power has become a primary consideration in hardware design, and is critical in computer systems especially for portable devices with high performance and more functionality. Clock-gating is the most common technique used for reducing processor's power. In this work clock gating technique is applied to optimize the power of fully programmable Embedded Controller (PEC) employing RISC architecture. The CPU designed supports i) smart instruction set, ii) I/O port, UART iii) on-chip clocking to provide a range of frequencies , iv) RISC as well as controller concepts. The whole design is captured using VHDL and is implemented on FPGA chip using Xilinx .The architecture and clock gating technique together is found to reduce the power consumption by 33.33% of total power consumed by this chip.

  6. Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered microprocessor-controlled knee for level walking.

    Science.gov (United States)

    Creylman, Veerle; Knippels, Ingrid; Janssen, Paul; Biesbrouck, Evelyne; Lechler, Knut; Peeraer, Louis

    2016-12-19

    In transfemoral (TF) amputees, the forward propulsion of the prosthetic leg in swing has to be mainly carried out by hip muscles. With hip strength being the strongest predictor to ambulation ability, an active powered knee joint could have a positive influence, lowering hip loading and contributing to ambulation mobility. To assess this, gait of four TF amputees was measured for level walking, first while using a passive microprocessor-controlled prosthetic knee (P-MPK), subsequently while using an active powered microprocessor-controlled prosthetic knee (A-MPK). Furthermore, to assess long-term effects of the use of an A-MPK, a 4-weeks follow-up case study was performed. The kinetics and kinematics of the gait of four TF amputees were assessed while walking with subsequently the P-MPK and the A-MPK. For one amputee, a follow-up study was performed: he used the A-MPK for 4 weeks, his gait was measured weekly. The range of motion of the knee was higher on both the prosthetic and the sound leg in the A-MPK compared to the P-MPK. Maximum hip torque (HT) during early stance increased for the prosthetic leg and decreased for the sound leg with the A-MPK compared to the P-MPK. During late stance, the maximum HT decreased for the prosthetic leg. The difference between prosthetic and sound leg for HT disappeared when using the A-MPK. Also, an increase in stance phase duration was observed. The follow-up study showed an increase in confidence with the A-MPK over time. Results suggested that, partially due to an induced knee flexion during stance, HT can be diminished when walking with the A-MPK compared to the P-MPK. The single case follow-up study showed positive trends indicating that an adaptation time is beneficial for the A-MPK.

  7. Radiation tolerant power converter controls

    CERN Document Server

    Todd, B; King, Q; Uznanski, S

    2012-01-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...

  8. Power control for ac motor

    Science.gov (United States)

    Dabney, R. W. (Inventor)

    1984-01-01

    A motor controller employing a triac through which power is supplied to a motor is described. The open circuit voltage appearing across the triac controls the operation of a timing circuit. This timing circuit triggers on the triac at a time following turn off which varies inversely as a function of the amplitude of the open circuit voltage of the triac.

  9. An Enhanced Dual Droop Control Scheme for Resilient Active Power Sharing among Paralleled Two-Stage Converters

    OpenAIRE

    Liu, Hongpeng; Yang, Yongheng; Wang, Xiongfei; Loh, Poh Chiang; Blaabjerg, Frede; Wang, Wei; Xu, Dianguo

    2017-01-01

    Traditional droop-controlled system has assumed that generators can always generate the powers demanded from them. This is true with conventional sources, where fuel supplies are usually planned in advance. For renewable sources, it may also be possible if energy storage is available. Energy storage, usually as batteries, may however be expensive, depending on its planned capacity. Renewable sources are therefore sometimes installed as non-dispatch-able sources without storage. This may not b...

  10. Radiation tolerant power converter controls

    Science.gov (United States)

    Todd, B.; Dinius, A.; King, Q.; Uznanski, S.

    2012-11-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to significantly increased radiation induced effects in materials close to the accelerator, including the FGC. Recent radiation tests indicate that the current FGC would not be sufficiently reliable. A so-called FGClite is being designed to work reliably in the radiation environment in the post-LS1 era. This paper outlines the concepts of power converter controls for machines such as the LHC, introduces the risks related to radiation and a radiation tolerant project flow. The FGClite is then described, with its key concepts and challenges: aiming for high reliability in a radiation field.

  11. Real-Time Control of Active and Reactive Power for Doubly Fed Induction Generator (DFIG-Based Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Aman Abdulla Tanvir

    2015-09-01

    Full Text Available This paper presents the modeling, rapid control prototyping, and hardware-in-the-loop testing for real-time simulation and control of a grid-connected doubly fed induction generator (DFIG in a laboratory-size wind turbine emulator for wind energy conversation systems. The generator is modeled using the direct-quadrature rotating reference frame circuit along with the aligned stator flux, and the field-oriented control approach is applied for independent control of the active and reactive power and the DC-link voltage at the grid side. The control of the active, reactive power and the DC-link voltage are performed using a back-to-back converter at sub- and super-synchronous as well as at variable speeds. The control strategy is experimentally validated on an emulated wind turbine driven by the Opal-RT real-time simulator (OP5600 for simultaneous control of the DC-link voltage, active and reactive power.

  12. Robust power system frequency control

    CERN Document Server

    Bevrani, Hassan

    2014-01-01

    This updated edition of the industry standard reference on power system frequency control provides practical, systematic and flexible algorithms for regulating load frequency, offering new solutions to the technical challenges introduced by the escalating role of distributed generation and renewable energy sources in smart electric grids. The author emphasizes the physical constraints and practical engineering issues related to frequency in a deregulated environment, while fostering a conceptual understanding of frequency regulation and robust control techniques. The resulting control strategi

  13. Distributed Power-Flow Controller (DPFC Simulation

    Directory of Open Access Journals (Sweden)

    T Jagan Mohan Rao

    2014-10-01

    Full Text Available This paper describes the steady-state response and control of power in transmission line equipped with FACTS devices. Detailed simulations are carried out on two -machine systems to illustrate the control features of these devices and their influence to increase power transfer capability and improve system reliability. The DPFC is derived from the unified power-flow controller (UPFC and DPFC has the same control capability as the UPFC. The DPFC can be considered as a UPFC with an eliminated common dc link. The active power exchange between the shunt and series converters, which is through the common dc link in the UPFC, is now through the transmission lines at the third -harmonic frequency. The interaction between the DPFC, the network and the machines are analyzed.

  14. Power generation, operation and control

    CERN Document Server

    Wood, Allen J; Sheblé, Gerald B

    2013-01-01

    Since publication of the second edition, there have been extensive changes in the algorithms, methods, and assumptions in energy management systems that analyze and control power generation. This edition is updated to acquaint electrical engineering students and professionals with current power generation systems. Algorithms and methods for solving integrated economic, network, and generating system analysis are provided. Also included are the state-of-the-art topics undergoing evolutionary change, including market simulation, multiple market analysis, multiple interchange contract analysis, c

  15. Autonomous and coordinated control of active power in standalone microgrid%独立微电网有功功率自主与协调控制

    Institute of Scientific and Technical Information of China (English)

    高春凤; 杨仁刚; 井天军

    2014-01-01

    Usually, a microgrid is connected to a power grid as a complement that enhances the flexibility and safety of a system. However, in some cases, for example grid faults, remote rural areas, or islands away from the continent, the microgrid has to operate independently. Because of a large number of power electronic components in the microgrid, the fluctuant distributed generation, and the bidirectional power flow, the unified coordination control of the units in each case is very important for the security and stability in the operation of each standalone microgrid. Aiming at the standalone microgrid, an autonomous and coordinated control method is designed in the paper. The primary adjustment is an independent local control strategy that allows each DG unit to operate autonomously. Also, for reliability reasons, communication is avoided in the primary adjustment, similar to the conventional grid control. Hence, it is based only on local measurements, being conceived as a local control strategy. With respect to the primary adjustment, in islanded mode, the DG units need to dispatch their power to enable power sharing and voltage control, thereby ensuring a stable microgrid operation. According to the voltage and active power control curve in autonomous control, the primary adjustment is completed by wind unit controller, solar unit controller, and energy storage controller. For the fast response of energy storage devices and large random fluctuations of intermittently distributed generations in the standalone microgrid without any continuous power supply, the voltage-frequency control method is adopted in energy storage devices to allocate automatically and absorb the transient imbalance power of the system during real time operating. Meanwhile, the PQ control method is adopted in intermittently distributed generations. The secondary adjustment is completed by the microgrid controller. According to the upper and lower limits of voltage and current of energy storage

  16. Concept and controllability of virtual power plant

    Energy Technology Data Exchange (ETDEWEB)

    Setiawan, E.A.

    2007-07-01

    In the end of 20th century the conception of electrical power supply is morphing gradually from centralized into decentralized system, indicated by increasing the installation of distributed generation on the main grid. With emerging of advanced communication and information technology, the aggregation control of several DG units can be developed as virtual power plant in order to provide added-value to the electric power system. This thesis presents definitions and types of Virtual Power Plants (VPP), then developing control through numerical simulation. The thesis proposes three DG controls namely Basic Autocontrol System (BAS), Smart Autocontrol System (SAS) and Tracking Efficiency Autocontrol System (TEAS). The BAS controls the DG output power with the objective to cover the local load demand. The drawback of this system is that the coordination among DG units is not established yet. In contrast to the BAS, the SAS has a control coordination centre which is responsible of controlling a certain number of DG units. The SAS controls and coordinates the operation of the dedicated DG units in order to minimize power exchange with the superior grid. However the efficiency issue is not considered at two previous control systems, therefore the TEAS was developed. Principally this system is similar to the SAS in terms of information exchange but additionally optimizes the operation efficiency of DG units. This is accomplished by tracking the systems' most efficient operation point. All control systems have been implemented into a simulation environment. The simulation results show that all developed control systems are capable to minimize the power exchange with the superior grid. The systems are able to follow changing load conditions. Furthermore the simulation results prove the ability of TEAS to optimize the system efficiency. Finally the contribution of VPP to voltage regulation is investigated with several scenarios. The influence of both, active and reactive

  17. Control voltage and power fluctuations when connecting wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Berinde, Ioan, E-mail: ioan-berinde@yahoo.com; Bălan, Horia, E-mail: hbalan@mail.utcluj.ro; Oros, Teodora Susana, E-mail: teodoraoros-87@yahoo.com [Technical University of Cluj-Napoca, Romania, Faculty of Electrical Engineering, Department of Power Engineering and Management (Romania)

    2015-12-23

    Voltage, frequency, active power and reactive power are very important parameters in terms of power quality. These parameters are followed when connecting any power plant, the more the connection of wind farms. Connecting wind farms to the electricity system must not cause interference outside the limits set by regulations. Modern solutions for fast and automatic voltage control and power fluctuations using electronic control systems of reactive power flows. FACTS (Flexible Alternating Current Transmision System) systems, established on the basis of power electronic circuits ensure control of electrical status quantities to achieve the necessary transfer of power to the power grid. FACTS devices can quickly control parameters and sizes of state power lines, such as impedance line voltages and phase angles of the voltages of the two ends of the line. Their use can lead to improvement in power system operation by increasing the transmission capacity of power lines, power flow control lines, improved static and transient stability reserve.

  18. Power Trading and Congestion Management Through Real Power Rescheduling Using Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    S.K. Gupta

    2014-09-01

    Full Text Available Congestion is termed as the operating condition in which there is not enough transmission capacity to implement all the desired transactions. This paper deals with the power trading in electricity market to ensure regular supply at competitive rates. Bidding process of 75 Indian bus systems is analyzed. It is shown that how can congestion cost can be addressed through active power rescheduling with transmission line constraints using Unified power flow controller.

  19. Optimization on active power of wind power generation control strategy based on sample wind turbine method%基于样板风机法的风电有功控制策略优化

    Institute of Scientific and Technical Information of China (English)

    王运; 朱建军

    2016-01-01

    Aiming at the equity problem due to lower accuracy of wind power prediction when restricted power gridconnected generation of wind farms for the same reason by using Automatic Generation Control (AGC)system,using the theoretical power reduced by sample wind turbine method as the gridconnected generation restricted basis,designs optimization control strategy for active power of wind power generation. The application result shows that this control strategy can effectively solve the equity problem of wind farms gridconnected generation restricted,promote wind power generation absorption and healthy development,improve the wind power gridconnected generation operation management level.%针对自动发电量控制(Automatic Generation Control,AGC )系统因同一原因对不同风电场进行限电时,由于风电预测准确性较低而产生的公平性问题,引入样板风机法还原的理论功率作为限电依据,设计了优化的风电有功控制策略。应用结果表明:该方法可以有效解决风电限电的公平性问题,促进风电的消纳和健康有序发展,提高风电并网运行管理水平。

  20. Power system dynamics and control

    CERN Document Server

    Kwatny, Harry G

    2016-01-01

    This monograph explores a consistent modeling and analytic framework that provides the tools for an improved understanding of the behavior and the building of efficient models of power systems. It covers the essential concepts for the study of static and dynamic network stability, reviews the structure and design of basic voltage and load-frequency regulators, and offers an introduction to power system optimal control with reliability constraints. A set of Mathematica tutorial notebooks providing detailed solutions of the examples worked-out in the text, as well as a package that will enable readers to work out their own examples and problems, supplements the text. A key premise of the book is that the design of successful control systems requires a deep understanding of the processes to be controlled; as such, the technical discussion begins with a concise review of the physical foundations of electricity and magnetism. This is followed by an overview of nonlinear circuits that include resistors, inductors, ...

  1. Modelling and Control Strategies of Microgrid in Grid-Connected and Islanded Operation Modes - Part I: Active Power Sharing and Frequency Control

    DEFF Research Database (Denmark)

    Wang, Lu; Hu, Yanting; Chen, Zhe

    2013-01-01

    at distributed voltage level. However, when a large number of DGs were connected to the AC power grid, it can cause power quality, grid security and stability issues. This paper presents an improved P-f droop control strategy using the reciprocal characteristic to improve the stability performance. Based......In recent years, the utilization of renewable energy resources has promoted more and more microgrid developed. The microgrid consists of distributed generations (DGs) associate with distributed energy resources (DERs), which are normally located next to the customer and provide electric power...... on simulation analyses with Matlab/Simulink, the results show that the presented droop control strategy has good effects in grid-connected and islanded mode, and during operation mode transitions....

  2. Wind power integration into the automatic generation control of power systems with large-scale wind power

    DEFF Research Database (Denmark)

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

    2014-01-01

    Transmission system operators have an increased interest in the active participation of wind power plants (WPP) in the power balance control of power systems with large wind power penetration. The emphasis in this study is on the integration of WPPs into the automatic generation control (AGC......) of the power system. The present paper proposes a coordinated control strategy for the AGC between combined heat and power plants (CHPs) and WPPs to enhance the security and the reliability of a power system operation in the case of a large wind power penetration. The proposed strategy, described...... and exemplified for the future Danish power system, takes the hour-ahead regulating power plan for generation and power exchange with neighbouring power systems into account. The performance of the proposed strategy for coordinated secondary control is assessed and discussed by means of simulations for different...

  3. 风电集群有功功率控制及其策略%Active Power Control of Wind Farm Cluster and Its Strategy

    Institute of Scientific and Technical Information of China (English)

    林俐; 朱晨宸; 郑太一; 焦邵华

    2014-01-01

    鉴于大规模风电并网的集中控制和精细化调度要求,文中基于区域有功功率分层调度思想,设计了风电调度中心站-风电集群控制主站-风电场控制执行站3层体系架构的风电集群有功功率控制系统,并给出风电集群控制主站和各场站间控制接口的设计方案。继而考虑风电场、分散接入风电机组的调节性能差异,针对运行实际需求提出一套面向集群控制主站的有功功率控制策略,实现风电场有功控制模式的在线决策和相应模式下的有功功率指令值的在线快速计算,并验证了控制策略的有效性。所建系统可实现风电集群内风电场、分散机组的统一调度与监控,并且在充分利用电网接纳风电能力的同时提高集群运行的经济性,有效解决目前风电分散控制导致的资源浪费、协调困难等问题。%According to the demand of centralized control and elaborated dispatch of large-scale wind power integrated to the power grid,an active power control system for the wind farm cluster is designed based on the hierarchical dispatch of regional active powers.The system adopting a three-tier structure is subdivided into the wind power dispatch station,wind farm cluster control station and wind farm execution station.The designed scheme of interface between the master control station and wind farms in the wind farm cluster is presented.Taking the regulation performance differences of various wind farms and scattered wind turbines into account,an active power control strategy for the master control station in the wind farm cluster is then proposed to realizing online decision-making of active power control mode for wind farms and fast online calculation of active power instruction values under corresponding modes.The validity of the control strategy has been proven through simulation. The result shows that the system can realize unified dispatch and monitoring of wind farms and

  4. The Power Quality Compensation Strategy for Power Distribution System Based on Hybrid Parallel Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rachid DEHINI

    2010-12-01

    Full Text Available In this paper, the main aim is to confront the performance of shunt active power filter (SAPF and the shunt hybrid active power filter (SHAPF to achieve flexibility and reliability of the filter devices. Both of the two devices used the classical proportional-integral controller for pulse generation to trigger the inventers MOSFET’s. In the adopted hybrid active filter there is a passive power filter with high power rating to filter the low order harmonies and one active filter with low power rating to filter the other high order harmonies. In order to investigate the effectiveness of (SHAPF, the studies have been accomplished using simulation with the MATLAB-SIMULINK. The results show That (SHAPF is more effective than (SAPF, and has lower cost.

  5. Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

    Directory of Open Access Journals (Sweden)

    Ivković Sanja

    2014-01-01

    Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

  6. Interday Reliability of Peak Muscular Power Outputs on an Isotonic Dynamometer and Assessment of Active Trunk Control Using the Chop and Lift Tests

    Science.gov (United States)

    Palmer, Thomas G.; Uhl, Timothy L.

    2011-01-01

    Abstract Context: Assessment techniques used to measure functional tasks involving active trunk control are restricted to linear movements that lack the explosive movements and dynamic tasks associated with activities of daily living and sport. Reliable clinical methods used to assess the diagonal and ballistic movements about the trunk are lacking. Objective: To assess the interday reliability of peak muscular power outputs while participants performed diagonal chop and lift tests and maintained a stable trunk. Design: Controlled laboratory study. Setting: University research laboratory. Patients or Other Participants: Eighteen healthy individuals (10 men and 8 women; age  =  32 ± 11 years, height  =  168 ± 12 cm, mass  =  80 ± 19 kg) from the general population participated. Intervention(s): Participants performed 2 power tests (chop, lift) using an isotonic dynamometer and 3 endurance tests (Biering-Sørensen, side-plank left, side-plank right) to assess active trunk control. Testing was performed on 3 different days separated by at least 1 week. Reliability was compared between days 1 and 2 and between days 2 and 3. Correlations between the power and endurance tests were evaluated to determine the degree of similarity. Main Outcome Measure(s): Peak muscular power outputs (watts) derived from a 1-repetition maximum protocol for the chop and lift tests were collected for both the right and left sides. Results: Intraclass correlation coefficients for peak muscular power were highly reliable for the chop (range, 0.87–0.98), lift (range, 0.83–0.96), and endurance (range, 0.80–0.98) tests between test sessions. The correlations between the power assessments and the Biering-Sørensen test (r range, −0.008 to 0.017) were low. The side-plank tests were moderately correlated with the chop (r range, 0.528–0.590) and the lift (r range, 0.359–0.467) tests. Conclusions: The diagonal chop and lift power protocol generated reliable data and

  7. Solar powered actuator with continuously variable auxiliary power control

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A solar powered system is disclosed in which a load such as a compressor is driven by a main induction motor powered by a solar array. An auxiliary motor shares the load with the solar powered motor in proportion to the amount of sunlight available, is provided with a power factor controller for controlling voltage applied to the auxiliary motor in accordance with the loading on that motor. In one embodiment, when sufficient power is available from the solar cell, the auxiliary motor is driven as a generator by excess power from the main motor so as to return electrical energy to the power company utility lines.

  8. Dynamic model of frequency control in Danish power system with large scale integration of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2013-01-01

    power system model with large scale of wind power is developed and a case study for an inaccurate wind power forecast is investigated. The goal of this work is to develop an adequate power system model that depicts relevant dynamic features of the power plants and compensates for load generation......This work evaluates the impact of large scale integration of wind power in future power systems when 50% of load demand can be met from wind power. The focus is on active power balance control, where the main source of power imbalance is an inaccurate wind speed forecast. In this study, a Danish...... imbalances, caused by inaccurate wind speed forecast, by an appropriate control of the active power production from power plants....

  9. Formation of the active medium in high-power repetitively pulsed gas lasers pumped by an electron-beam-controlled discharge

    Science.gov (United States)

    Bulaev, V. D.; Lysenko, S. L.

    2015-07-01

    A high-power repetitively pulsed e-beam-controlled discharge CO2 laser is simulated numerically; the simulation results are compared with experimental data. Optimal sizes and design of electrodes and configuration of the external magnetic field are found, which allow one to introduce no less than 90% electric pump energy into a specified volume of the active medium, including the active volume of a laser with an aperture of 110 × 110 cm. The results obtained can also be used to design other types of highpower gas lasers.

  10. Development of Active Temperature Control System for High-power LED%大功率LED有源温控系统的开发

    Institute of Scientific and Technical Information of China (English)

    刘世俊; 刘超

    2011-01-01

    Most of the power energy of high-power LEDs convert into the heat energy when it is turned on. The light intensity and life time of high-power LED will be influenced seriously if the heat energy can not be diffused efficently. Considering the actual demand of the high-power LED heat dissipation) a LED active temperature control system is presented in this paper. The LED driver is used as the refrigeration driver power supply of TEC. The temperature monitoring circuit based on the semiconductor transducer is made. The closed-loop control system is formed through PI regulator. The tested data shows that the LED active temperature control system is stable and reliable.%由于大功率LED供电时其大部分能量转化为热能,如果热量不能有效散出,将严重影响其光照亮度及其使用寿命.为了大功率LED散热的实际需要,提出并实现了一种LED有源温控系统的开发,采用热电制冷效应,使用LED驱动器本身作为制冷器的驱动电源,同时建立基于半导体传感器的温控监测电路,通过内部数字PI调节器形成一个完整的闭环控制系统,最后获得LED有源温控系统的具体配置方式,并分析测试的数据结果,展示了有源温控系统的准确性和可靠性.

  11. Flicker Mitigation by Active Power Control of Variable-Speed Wind Turbines With Full-Scale Back-to-Back Power Converters

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Wang, Zhaoan

    2009-01-01

    Grid-connected wind turbines are fluctuating power sources that may produce flicker during continuous operation.This paper presents a simulation model of a megawatt-level variablespeed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of PSCAD/EMTDC. Fli...

  12. Voting Power and Shareholder Activism

    DEFF Research Database (Denmark)

    Strand, Therese; Poulsen, Thomas; Thomsen, Steen

    2010-01-01

    The article discusses the development of a voting power theory that is applied to a unique data set on Swedish shareholder meetings. The authors hypothesize that there is a positive relationship between shareholder activism and the largest shareholder's sensitivity to greater participation by small...

  13. Dynamic Reactive Power Control in Offshore HVDC Connected Wind Power Plants

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Cutululis, Nicolaos Antonio; Rather, Zakir Hussain;

    2016-01-01

    This paper presents a coordinated reactive power control for a HVDC connected cluster of offshore wind power plants (WPPs). The reactive power reference for the WPP cluster is estimated by an optimization algorithm aiming at minimum active power losses in the offshore AC Grid. For each optimal...

  14. Development of novel activated carbon-based adsorbents for the control of mercury emissions from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Radisav D. Vidic

    1999-03-01

    In addition to naturally occurring mercury sources, anthropogenic activities increase the mercury loading to the environment. Although not all produced mercury is dissipated directly into the environment, only minor portions of the total production are stocked or recycled, and the rest of the mercury and its compounds is finally released in some way into atmosphere, surface waters and soil, or ends in landfills dumps, and refuse. Since mercury and its compounds are highly toxic, their presence in the environment constitutes potential impact on all living organisms, including man. The first serious consequence of industrial mercury discharges causing neurological disorder even death occurred in Minimata, Japan in 1953. Systematic studies showed that mercury poisoning is mainly found in fish-eating populations. However, various levels of mercury are also found in food other than fish. During the past several decades, research has been conducted on the evaluation of risks due to exposure to mercury and the development of control technologies for mercury emissions. In 1990, the Clean Air Act Amendments listed mercury, along with 10 other metallic species, as a hazardous air pollutant (HAP). This has further stimulated research for mercury control during the past several years. The impact of mercury on humans, sources of mercury in the environment, current mercury control strategies and the objective of this research are discussed in this section.

  15. Design of power control system using SMES and SVC for fusion power plant

    Science.gov (United States)

    Niiyama, K.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2008-02-01

    A SMES (Superconducting Magnetic Energy Storage System) system with converter composed of self-commutated valve devices such as GTO and IGBT is available to control active and reactive power simultaneously. A SVC (Static Var Compensators) or STATCOM (Static Synchronous Compensator) is widely employed to reduce reactive power in power plants and substations. Owing to progress of power electronics technology using GTO and IGBT devices, power converters in the SMES system and the SVC can easily control power flow in few milliseconds. Moreover, since the valve devices for the SMES are equivalent to those for the SVC, the device cost must be reduced. In this paper the basic control system combined with the SMES and SVC is designed for large pulsed loads of a nuclear fusion power plant. This combined system largely expands the reactive power control region as well as the active one. The simulation results show that the combined system is effective and prospective for the nuclear fusion power plant.

  16. Wind power integration into the automatic generation control of power systems with large-scale wind power

    Directory of Open Access Journals (Sweden)

    Abdul Basit

    2014-10-01

    Full Text Available Transmission system operators have an increased interest in the active participation of wind power plants (WPP in the power balance control of power systems with large wind power penetration. The emphasis in this study is on the integration of WPPs into the automatic generation control (AGC of the power system. The present paper proposes a coordinated control strategy for the AGC between combined heat and power plants (CHPs and WPPs to enhance the security and the reliability of a power system operation in the case of a large wind power penetration. The proposed strategy, described and exemplified for the future Danish power system, takes the hour-ahead regulating power plan for generation and power exchange with neighbouring power systems into account. The performance of the proposed strategy for coordinated secondary control is assessed and discussed by means of simulations for different possible future scenarios, when wind power production in the power system is high and conventional production from CHPs is at a minimum level. The investigation results of the proposed control strategy have shown that the WPPs can actively help the AGC, and reduce the real-time power imbalance in the power system, by down regulating their production when CHPs are unable to provide the required response.

  17. Periodic Control of Power Electronic Converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Danwei, Wang; Yang, Yongheng

    Advanced power electronic converters convert, control and condition electricity. Power converters require control strategies for periodic signal compensation to assure good power quality and stable power system operation. This comprehensive text presents the most recent internal model principle...... based periodic control technology, which offers the perfect periodic control solution for power electronic conversion. It also provides complete analysis and synthesis methods for periodic control systems, and plenty of practical examples to demonstrate the validity of proposed periodic control...... technology for power converters. It proposes a unified framework for housing periodic control schemes for power converters, and provides a general proportional-integral-derivative control solution to periodic signal compensation in extensive engineering applications. Periodic Control of Power Electronic...

  18. A Refined Self-Tuning Filter-Based Instantaneous Power Theory Algorithm for Indirect Current Controlled Three-Level Inverter-Based Shunt Active Power Filters under Non-sinusoidal Source Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yap Hoon

    2017-02-01

    Full Text Available In this paper, a refined reference current generation algorithm based on instantaneous power (pq theory is proposed, for operation of an indirect current controlled (ICC three-level neutral-point diode clamped (NPC inverter-based shunt active power filter (SAPF under non-sinusoidal source voltage conditions. SAPF is recognized as one of the most effective solutions to current harmonics due to its flexibility in dealing with various power system conditions. As for its controller, pq theory has widely been applied to generate the desired reference current due to its simple implementation features. However, the conventional dependency on self-tuning filter (STF in generating reference current has significantly limited mitigation performance of SAPF. Besides, the conventional STF-based pq theory algorithm is still considered to possess needless features which increase computational complexity. Furthermore, the conventional algorithm is mostly designed to suit operation of direct current controlled (DCC SAPF which is incapable of handling switching ripples problems, thereby leading to inefficient mitigation performance. Therefore, three main improvements are performed which include replacement of STF with mathematical-based fundamental real power identifier, removal of redundant features, and generation of sinusoidal reference current. To validate effectiveness and feasibility of the proposed algorithm, simulation work in MATLAB-Simulink and laboratory test utilizing a TMS320F28335 digital signal processor (DSP are performed. Both simulation and experimental findings demonstrate superiority of the proposed algorithm over the conventional algorithm.

  19. Power inverter implementing phase skipping control

    Science.gov (United States)

    Somani, Utsav; Amirahmadi, Ahmadreza; Jourdan, Charles; Batarseh, Issa

    2016-10-18

    A power inverter includes a DC/AC inverter having first, second and third phase circuitry coupled to receive power from a power source. A controller is coupled to a driver for each of the first, second and third phase circuitry (control input drivers). The controller includes an associated memory storing a phase skipping control algorithm, wherein the controller is coupled to receive updating information including a power level generated by the power source. The drivers are coupled to control inputs of the first, second and third phase circuitry, where the drivers are configured for receiving phase skipping control signals from the controller and outputting mode selection signals configured to dynamically select an operating mode for the DC/AC inverter from a Normal Control operation and a Phase Skipping Control operation which have different power injection patterns through the first, second and third phase circuitry depending upon the power level.

  20. Design of Controller for New EAST Fast Control Power Supply

    Institute of Scientific and Technical Information of China (English)

    HUANG Haihong; YIN Ming; WANG Haixin

    2014-01-01

    The effectiveness of the magnetic confinement of plasma can be improved by elongating the plasma cross-section in tokamak devices.But elongated plasma has vertical displacement instability,so a feedback control system is needed to restrain the plasma's vertical displacement.A fast control power supply is needed to excite the active feedback coils,which produces a magnetic field to control the plasma's displacement.With the development of EAST,the fast control power supply needs to keep on enhancing the fast response and output current.The structure of a new power supply is introduced in this paper.The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control.According to the design demands of the EAST fast control power supply,the adjuster of the current close loop is applied to the inverter,which can advance its ability to restrain the loop current in low frequency and DC output.The result of the experiment confirms the validity of the proposed scheme and control strategy.

  1. The effect of unified power flow controller location in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Tumay, M. [Cukurova University, Baliai-Adana (Turkey). Department of Electrical and Electronic Engineering; Vural, A.M. [Gaziantep University (Turkey). Department of Electrical and Electronic Engineering; Lo, K.L. [University of Strathclyde, Glasgow (United Kingdom). Department of Electrical and Electronic Engineering

    2004-09-01

    The Unified Power Flow Controller (UPFC) is a device that is capable of providing control of voltage magnitude, active and reactive power flows. This paper represents the effect of UPFC location in steady-state analysis and to demonstrate the capabilities of UPFC in controlling active and reactive power flow within any electrical network. In this paper, a complete power injection model of UPFC including both the series injection branch and the shunt exciting branch is derived in rectangular form. An injected power model method is used to represent UPFC in load flow program. Finally, different types of simulation tasks are carried out based on IEEE 30-bus test system. (author)

  2. Active Power Regulation based on Droop for AC Microgrid

    DEFF Research Database (Denmark)

    Li, Chendan; Coelho, Ernane A. A.; Firoozabadi, Mehdi Savaghebi

    2015-01-01

    In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed to succes......In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed...

  3. Power Ramp Limitation capabilities of Large PV Power Plants with Active Power Reserves

    DEFF Research Database (Denmark)

    Bogdan, Craciun; Kerekes, Tamas; Sera, Dezso

    2017-01-01

    Power Ramp Limitation (PRL) is likely to become a requirement for large scale photovoltaic power plants (LPVPPs) in order to allow the increase of PV penetration levels. Especially in islands with reduced inertia capability, this problem is more stringent: high power ramp can be caused by either...... fast irradiance changes or other participant generators for example wind power, or loads. In order to compensate for the power mismatch, LPVPPs must use Active Power Reserve (APR), by either curtailment or auxiliary storage. The paper proposes a PRL control structure for dynamic APR sizing...... area of LPVPPs acts as filter against fast irradiance changes, the study reveals also the required plant size for which auxiliary storage is no longer needed in order to comply with PRL requirements – an important economical aspect....

  4. Coodinative Control of Active Power and DC-link Voltage for Cascaded Dual-Active-Bridge and Inverter in Bidirectional Applications

    DEFF Research Database (Denmark)

    Tian, Yanjun; Chen, Zhe; Deng, Fujin;

    2014-01-01

    A bidirectional interface converter is attractive for the flexible operation and control of a system consisting of a DC sub-grid and an AC sub-grid. Cascaded connection of a dual-active-bridge (DAB) with an inverter is an ideal topology for the bidirectional interface. However, due to the bidirec......A bidirectional interface converter is attractive for the flexible operation and control of a system consisting of a DC sub-grid and an AC sub-grid. Cascaded connection of a dual-active-bridge (DAB) with an inverter is an ideal topology for the bidirectional interface. However, due...

  5. Advanced Coordinating Control System for Power Plant

    Institute of Scientific and Technical Information of China (English)

    WU Peng; WEI Shuangying

    2006-01-01

    The coordinating control system is popular used in power plant. This paper describes the advanced coordinating control by control methods and optimal operation, introduces their principals and features by using the examples of power plant operation. It is wealthy for automation application in optimal power plant operation.

  6. Power flow control using quadrature boosters

    Science.gov (United States)

    Sadanandan, Sandeep N.

    A power system that can be controlled within security constraints would be an advantage to power planners and real-time operators. Controlling flows can lessen reliability issues such as thermal limit violations, power stability problems, and/or voltage stability conditions. Control of flows can also mitigate market issues by reducing congestion on some lines and rerouting power to less loaded lines or onto preferable paths. In the traditional control of power flows, phase shifters are often used. More advanced methods include using Flexible AC Transmission System (FACTS) Controllers. Some examples include Thyristor Controlled Series Capacitors, Synchronous Series Static Compensators, and Unified Power Flow Controllers. Quadrature Boosters (QBs) have similar structures to phase-shifters, but allow for higher voltage magnitude during real power flow control. In comparison with other FACTS controllers QBs are not as complex and not as expensive. The present study proposes to use QBs to control power flows on a power system. With the inclusion of QBs, real power flows can be controlled to desired scheduled values. In this thesis, the linearized power flow equations used for power flow analysis were modified for the control problem. This included modifying the Jacobian matrix, the power error vector, and calculating the voltage injected by the quadrature booster for the scheduled real power flow. Two scenarios were examined using the proposed power flow control method. First, the power flow in a line in a 5-bus system was modified with a QB using the method developed in this thesis. Simulation was carried out using Matlab. Second, the method was applied to a 30-bus system and then to a 118-bus system using several QBs. In all the cases, the calculated values of the QB voltages led to desired power flows in the designated line.

  7. Power System Stability Enhancement Using Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2010-01-01

    Full Text Available Problem statement: The enhancement of transient stability of the power system is one of the most challenging research areas in power engineer. Approach: This study presents the method to enhance transient stability of power system by Unified Power Flow Controller (UPFC. The mathematical model of power system equipped with a UPFC is systematically derived. The parameters of UPFC are modeled into power flow equation and thus it is used to determine control strategy. The swing curves of the three phase faulted power system without and with a UPFC are tested and compared in various cases. Results: The swing curve of system without a UPFC gets increases monotonically and thus the system can be considered as unstable whereas the swing curves of system with a UPFC can return to stable equilibrium point. Conclusion: From the simulation results, the UPFC can enhance transient stability of power system.

  8. The electric power engineering handbook power system stability and control

    CERN Document Server

    Grisby, Leonard L

    2012-01-01

    With contributions from worldwide leaders in the field, Power System Stability and Control, Third Edition (part of the five-volume set, The Electric Power Engineering Handbook) updates coverage of recent developments and rapid technological growth in essential aspects of power systems. Edited by L.L. Grigsby, a respected and accomplished authority in power engineering, and section editors Miroslav Begovic, Prabha Kundur, and Bruce Wollenberg, this reference presents substantially new and revised content. Topics covered include: * Power System Protection * Power System Dynamics and Stability *

  9. CCLIBS: The CERN Power Converter Control Libraries

    CERN Document Server

    AUTHOR|(SzGeCERN)404953; Lebioda, Krzysztof Tomasz; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille

    2015-01-01

    Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...

  10. Remote Power Control of Ethernet PON System

    Institute of Scientific and Technical Information of China (English)

    Inkwun Jung; Chunghwan Lim; Youngil Park

    2003-01-01

    A power control scheme to make all ONU channels’ power received at OLT nearly equal is proposed. Implemented by monitoring powers at OLT and sending control message to each ONU, it helps data recovery from the burst type upstream optical signals.

  11. A hybrid approach to space power control

    Science.gov (United States)

    Gholdston, E. W.; Janik, D. F.; Newton, K. A.

    1990-01-01

    Conventional control systems have traditionally been utilized for space-based power designs. However, the use of expert systems is becoming important for NASA applications. Rocketdyne has been pursuing the development of expert systems to aid and enhance control designs of space-based power systems. The need for integrated expert systems is vital for the development of autonomous power systems.

  12. Remote Power Control of Ethernet PON System

    Institute of Scientific and Technical Information of China (English)

    Inkwun; Jung; Chunghwan; Lim; Youngil; Park

    2003-01-01

    A power control scheme to make all ONU channels' power received at OLT nearly equal is proposed. Implemented by monitoring powers at OLT and sending control message to each ONU, it helps data recovery from the burst type upstream optical signals.

  13. Voluntary muscle activation improves with power training and is associated with changes in gait speed in mobility-limited older adults - A randomized controlled trial.

    Science.gov (United States)

    Hvid, Lars G; Strotmeyer, Elsa S; Skjødt, Mathias; Magnussen, Line V; Andersen, Marianne; Caserotti, Paolo

    2016-07-01

    Incomplete voluntary muscle activation may contribute to impaired muscle mechanical function and physical function in older adults. Exercise interventions have been shown to increase voluntary muscle activation, although the evidence is sparse for mobility-limited older adults, particularly in association with physical function. This study examined the effects of 12weeks of power training on outcomes of voluntary muscle activation and gait speed in mobility-limited older adults from the Healthy Ageing Network of Competence (HANC) study. We included 37 older men and women with a usual gait speed of analysis: n=16 in the training group (TG: 12weeks of progressive high-load power training, 2 sessions per week; age: 82.3±1.3years, 56% women) and n=21 in the control group (CG: no interventions; age: 81.6±1.1years, 67% women). Knee extensor muscle thickness (ultrasonography), strength (isokinetic dynamometry), voluntary activation (interpolated twitch technique), and gait speed (2-min maximal walking test) were assessed at baseline and post-intervention. At baseline, TG and CG were comparable for all measures. Post-intervention, significant between-group changes (TG vs. CG; pgait speed (+0.12m/s), whereas the between-group change in muscle thickness was non-significant (+0.08cm). Improvements in voluntary muscle activation were associated with improvements in gait speed in TG (r=0.67, ppower training, and is associated with improved maximal gait speed. Incomplete voluntary muscle activation should be considered one of the key mechanisms influencing muscle mechanical function and gait speed in older adults.

  14. Joint excitation and reactive power control in thermal power plant

    Directory of Open Access Journals (Sweden)

    Dragosavac Jasna

    2013-01-01

    Full Text Available The coordinated voltage and reactive power controller, designed for the thermal power plant, is presented in the paper. A brief explanation of the need for such device is given and justification for commissioning of such equipment is outlined. After short description of the theoretical background of the proposed control design, the achieved features of the commissioned equipment are fully given. Achieved performances are illustrated by recorded reactive power and bus voltage responses after commissioning of the described equipment into the largest thermal power plant in Serbia. As it can be seen in presented records, all design targets are met.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Autonomous power system intelligent diagnosis and control

    Science.gov (United States)

    Ringer, Mark J.; Quinn, Todd M.; Merolla, Anthony

    1991-01-01

    The Autonomous Power System (APS) project at NASA Lewis Research Center is designed to demonstrate the abilities of integrated intelligent diagnosis, control, and scheduling techniques to space power distribution hardware. Knowledge-based software provides a robust method of control for highly complex space-based power systems that conventional methods do not allow. The project consists of three elements: the Autonomous Power Expert System (APEX) for fault diagnosis and control, the Autonomous Intelligent Power Scheduler (AIPS) to determine system configuration, and power hardware (Brassboard) to simulate a space based power system. The operation of the Autonomous Power System as a whole is described and the responsibilities of the three elements - APEX, AIPS, and Brassboard - are characterized. A discussion of the methodologies used in each element is provided. Future plans are discussed for the growth of the Autonomous Power System.

  17. Impact of wind power in autonomous power systems—power fluctuations—modelling and control issues

    DEFF Research Database (Denmark)

    Margaris, Ioannis D.; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio;

    2011-01-01

    technologies, power system protection and load. Analytical models for wind farms with three different wind turbine technologies, namely Doubly Fed Induction Generator, Permanent Magnet Synchronous Generator and Active Stall Induction Generator-based wind turbines, are included. Likewise, analytical models...... for diesel and steam generation plants are applied. The power grid, including speed governors, automatic voltage regulators, protection system and loads is modelled in the same platform. Results for different load and wind profile cases are being presented for the case study of the island Rhodes, in Greece......This paper describes a detailed modelling approach to study the impact of wind power fluctuations on the frequency control in a non-interconnected system with large-scale wind power. The approach includes models for wind speed fluctuations, wind farm technologies, conventional generation...

  18. Pool power control in remelting systems

    Science.gov (United States)

    Williamson, Rodney L.; Melgaard, David K.; Beaman, Joseph J.

    2011-12-13

    An apparatus for and method of controlling a remelting furnace comprising adjusting current supplied to an electrode based upon a predetermined pool power reference value and adjusting the electrode drive speed based upon the predetermined pool power reference value.

  19. Integrated high voltage power supply utilizing burst mode control and its performance impact on dielectric electro active polymer actuators

    DEFF Research Database (Denmark)

    Andersen, Thomas; Rødgaard, Martin Schøler; Andersen, Michael A. E.;

    a burst mode control technique. Controlling and driving a DEAP actuator between 250V to 2.5kV is demonstrated, where discrete like voltage change and voltage ripple is observed, which is introduced by the burst mode control. Measurements of the actuator strain-force reveal that the voltage ripples...... translates to small strain-force ripples. Nevertheless the driver demonstrates good capabilities of following an input reference signal, as well as having the size to fit inside a 110 mm x 32 mm cylindrical InLastor Push actuator, forming a “low voltage” DEAP actuator....

  20. Digital power factor control and reactive power regulation for grid-connected photovoltaic inverter

    Energy Technology Data Exchange (ETDEWEB)

    Hassaine, L. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria); Olias, E.; Quintero, J. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Haddadi, M. [Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria)

    2009-01-15

    The overall efficiency of photovoltaic (PV) systems connected to the grid depends on the efficiency of direct current (DC) of the solar modules to alternate current (AC) inverter conversion. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, high power factor and low total harmonic distortion of the currents injected into the grid. An approach to power factor control and reactive power regulation for PV systems connected to the grid using field programmable gate array (FPGA) is proposed. According to the grid demands; both the injected active and reactive powers are controlled. In this paper, a new digital control strategy for a single-phase inverter is carried out. This control strategy is based on the phase shift between the inverter output voltage and the grid voltage, and the digital sinusoidal pulse width modulation (DSPWM) patterns, in order to control the power factor for a wide range of the inverter output current and consequently the control and the regulation of the reactive power will be achieved. The advantage of the proposed control strategy is its implementation around simple digital circuits. In this work, a simulation study of this strategy has been realized using Matlab/Simulink and PSIM. In order to validate its performance, this control has been implemented in a FPGA. Experimental tests have been carried out demonstrating the viability of this control in order to control the power factor and the injected power into the grid. (author)

  1. Optically powered active sensing system for Internet Of Things

    Science.gov (United States)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  2. Interface of magnetoresistive converter of active power

    Directory of Open Access Journals (Sweden)

    A. I. Vytiaganets

    2009-10-01

    Full Text Available The vehicle and programmatic interfaces of magnetoresistive converter of active power are considered, the results of statistical treatment of the multiple measuring of active-power are analysed.

  3. DC-Link Capacitor Voltage Regulation for Three-Phase Three-Level Inverter-Based Shunt Active Power Filter with Inverted Error Deviation Control

    Directory of Open Access Journals (Sweden)

    Yap Hoon

    2016-07-01

    Full Text Available A new control technique known as inverted error deviation (IED control is incorporated into the main DC-link capacitor voltage regulation algorithm of a three-level neutral-point diode clamped (NPC inverter-based shunt active power filter (SAPF to enhance its performance in overall DC-link voltage regulation so as to improve its harmonics mitigation performances. In the SAPF controller, DC-link capacitor voltage regulation algorithms with either the proportional-integral (PI or fuzzy logic control (FLC technique have played a significant role in maintaining a constant DC-link voltage across the DC-link capacitors. However, both techniques are mostly operated based on a direct voltage error manipulation approach which is insufficient to address the severe DC-link voltage deviation that occurs during dynamic-state conditions. As a result, the conventional algorithms perform poorly with large overshoot, undershoot, and slow response time. Therefore, the IED control technique is proposed to precisely address the DC-link voltage deviation. To validate effectiveness and feasibility of the proposed algorithm, simulation work in MATLAB-Simulink and experimental implementation utilizing a TMS320F28335 Digital Signal Processor (DSP are performed. Moreover, conventional algorithms with PI and FLC techniques are tested too for comparison purposes. Both simulation and experimental results are presented, confirming the improvement achieved by the proposed algorithm in terms of accuracy and dynamic response in comparison to the conventional algorithms.

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

    Directory of Open Access Journals (Sweden)

    Zbigniew Szczerba

    2012-06-01

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

  5. Agent-based power sharing scheme for active hybrid power sources

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhenhua [Department of Electrical and Computer Engineering, University of Miami, Coral Gables, FL 33146 (United States)

    2008-02-15

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles. (author)

  6. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  7. 基于ATX主板的TPCM主动度量及电源控制设计%The TPCM Active Measurement and Power Control Design for ATX Motherboard

    Institute of Scientific and Technical Information of China (English)

    黄坚会; 石文昌

    2016-01-01

    This paper proposes an active measurement and control method of the trusted platform control module (TPCM) based on advanced technology extended (ATX) motherboard. Keeping the original design of the motherboard unchanged, the existing interfaces of the computer motherboard are extended to protect the boot code from been tampered and attacked from the ifrst CPU instruction. Combined with the realization of the power control, the method can fundamentally solve the problem that the source of the boot is not to be trusted. This design makes sure the TPCM has been powered on ifrstly and lets the TPCM lead the power control system of the computer, measuring the credibility and the integrity of the boot code. If the BIOS and any other ifrmware have been maliciously tampered, the TPCM enter untrusted operation environment or prevent the computer from been powered on according to the pre written security policy in TPCM. The TPCM designed by this method has active and absolute control right on the computer. Once the malicious code invades and the system is out of control, the TPCM can take the absolute protection measures such as taking off the computer and cutting off the power. The method is not only reliable and effective, but also has the advantages of low cost and simple installation.%文章提出一种基于ATX主板的可信平台控制模块(TPCM)主动度量及电源控制实现方法。该方法在保持主板原有设计的基础上,利用计算机主板已有的接口进行扩展设计,达到从第一条CPU指令开始的启动代码防篡改和防攻击的目的。结合电源控制的实现,该方法可以从根本上解决计算机启动源头代码不可信问题。该方法确保可信平台控制模块首先上电,主导计算机电源控制系统,度量启动代码的可信性和完整性。若检测到BIOS等固件信息被恶意篡改,则根据预先写在可信平台控制模块内部的安全策略进入非可信工作模式或阻止

  8. Investigating power control in autonomous power systems with increasing wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Margaris, Ioannis D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Hansen, Anca D.; Sorensen, Poul [Risoe National Laboratory, Roskilde (Denmark). Wind Energy Dept.; Hatziargyriou, Nikos D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Public Power Corporation S.A., Athens (Greece)

    2009-07-01

    Increasing levels of wind penetration in autonomous power systems has set intensively high standards with respect to wind turbine technology during the last years. Special features of non-interconnected power systems make security issues rather critical, as the operation of large wind farms like conventional power plants is becoming a necessity. This paper includes the study case of Rhodos island, in Greece, where rapidly increasing wind penetration has started to impose serious security issues for the immediate future. The scenarios studied here correspond to reference year of study 2012 and include wind farms with three different wind turbine technologies - namely Doubly Fed Induction Generator (DFIG), Permanent Magnet Synchronous Generator (PMSG) and Active Stall Induction Generator (ASIG) based wind turbines. Aggregated models of the wind farms are being used and results for different load cases are being analyzed and discussed. The ability of wind farms to assist in some of the power system control services traditionally carried out by conventional synchronous generation is being investigated and discussed. The power grid of the island, including speed governors and automatic voltage regulators, is simulated in the dedicated power system simulation program Power Factory from DIgSILENT. (orig.)

  9. Power flow model/calculation for power systems with multiple FACTS controllers

    Energy Technology Data Exchange (ETDEWEB)

    Radman, Ghadir; Raje, Reshma S. [Center for Energy Systems Research, Tennessee Technological University, P.O. Box 5004, Cookeville, Tennessee-38505 (United States)

    2007-10-15

    This paper presents a new procedure for steady state power flow calculation of power systems with multiple flexible AC transmission system (FACTS) controllers. The focus of this paper is to show how the conventional power flow calculation method can systematically be modified to include multiple FACTS controllers. Newton-Raphson method of iterative solution is used for power flow equations in polar coordinate. The impacts of FACTS controllers on power flow is accommodated by adding new entries and modifying some existing entries in the linearized Jacobian equation of the same system with no FACTS controllers. Three major FACTS controllers (STATic synchronous COMpensator (STATCOM), static synchronous series compensator (SSSC), and unified power flow controller (UPFC)) are studied in this paper. STATCOM is modeled in voltage control mode. SSSC controls the active power of the link to which it is connected. The UPFC controls the active and the reactive power flow of the link while maintaining a constant voltage at one of the buses. The modeling approach presented in this paper is tested on the 9-bus western system coordinating council (WSCC) power system and implemented using MATLAB software package. The numerical results show the robust convergence of the presented procedure. (author)

  10. An novel analog programmable power supply for active gain control of the Multi-Pixel Photon Counter (MPPC)

    CERN Document Server

    Li, Zhengwei; Xu, Yupeng; Yan, Bo; Li, Yanguo; Lu, Xuefeng; Li, Xufang; Zhang, Shuo; Chang, Zhi; Li, Jicheng; Zhang, Yifei; Zhao, Jianling

    2016-01-01

    Silicon Photo-Multipliers (SiPM) are regarded as novel photo-detector to replace conventional Photo-Multiplier Tubes (PMTs). However, the breakdown voltage dependence on the ambient temperature results in a gain variation of $\\sim$3$\\% /^{\\circ} \\mathrm C$. This can severely limit the application of this device in experiments with wide range of operating temperature, especially in space telescope. An experimental setup in dark condition was established to investigate the temperature and bias voltage dependence of gain for the Multi-Pixel Photon Counter (MPPC), one type of the SiPM developed by Hamamatsu. The gain and breakdown voltage dependence on operating temperature of an MPPC can be approximated by a linear function, which is similar to the behavior of a zener diode. The measured temperature coefficient of the breakdown voltage is $(59.4 \\pm 0.4$ mV)$/^{\\circ} \\mathrm C$. According to this fact, a programmable power supply based on two zener diodes and an operational amplifier was designed with a positiv...

  11. Power Control Method for Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Baang, Dane; Suh, Yongsuk; Park, Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Considering safety-oriented design concept and other control environment, we developed a simple controller that provides limiting function of power change- rate as well as fine tracking performance. The design result has been well-proven via simulation and actual application to a TRIGA-II type research reactor. The proposed controller is designed to track the PDM(Power Demand) from operator input as long as maintaining the power change rate lower than a certain value for stable reactor operation. A power control method for a TRIGA-II type research reactor has been designed, simulated, and applied to actual reactor. The control performance during commissioning test shows that the proposed controller provides fine control performance for various changes in reference values (PDM), even though there is large measurement noise from neutron detectors. The overshoot at low power level is acceptable in a sense of reactor operation.

  12. Power effects on cognitive control: Turning conflict into action.

    Science.gov (United States)

    Schmid, Petra C; Kleiman, Tali; Amodio, David M

    2015-06-01

    Power is known to promote effective goal pursuit, especially when it requires one to overcome distractions or bias. We proposed that this effect involves the ability to engage and implement cognitive control. In Study 1, we demonstrated that power enhances behavioral performance on a response conflict task and that it does so by enhancing controlled processing rather than by reducing automatic processing. In Study 2, we used an event-related potential index of anterior cingulate activity to test whether power effects on control were due to enhanced conflict sensitivity or action implementation. Power did not significantly affect neural sensitivity to conflict; rather, high power was associated with a stronger link between conflict processing and intended action, relative to low power. These findings suggest a new perspective on how social factors can affect controlled processing and offer new evidence regarding the transition between conflict detection and the implementation of action control.

  13. Thyristor Controlled Reactor for Power Factor Improvement

    Directory of Open Access Journals (Sweden)

    Sheila Mahapatra

    2014-04-01

    Full Text Available Power factor improvement is the essence of any power sector for reliable operation. This paper provides Thyristor Controlled Reactor regulated by programmed microcontroller which aids in improving power factor and retaining it close to unity under various loading conditions. The implementation is done on 8051 microcontrollerwhich isprogrammed using Keil software. To determine time lag between current and voltage PSpice softwareis used and to display power factor according tothe variation in loadProteus software is used. Whenever a capacitive load is connected to the transmission linea shunt reactor is connected which injects lagging reactive VARs to the power system. As a result the power factor is improved. The results given in this paper provides suitable microcontroller based reactive power compensation and power factor improvement technique using a Thyristor Controlled Reactor module.

  14. 混合有源滤波器的复合控制研究%Complex control of hybrid active power filter

    Institute of Scientific and Technical Information of China (English)

    赵丽娜; 郭立杰; 李振明

    2012-01-01

    The working principle of the injection HAPF was analyzed, which could reduce the based voltage of active part and the capacity of active part, and effectively overcome switch device capacity and cost factor, more suitable for high pressure system. A composite control scheme through testing the power current and load current was presented. By controlling the above two values, the impedance series and parallel resonance of the system could be prevented, and thereby achieve the purpose of suppressing the harmonic.%分析了注入式混合有源滤波器的工作原理,它可以降低有源部分的基波分压,减少有源部分容量,更适用于高压系统,还可以有效地克服了开关器件容量和成本等因素的影响.提出了一种通过检测电网电流和负载谐波电流的复合控制方案.通过控制上述两个量来防止系统阻抗间可能的串并联谐振,而达到抑制电网谐波的目的.

  15. Electric power distribution, automation, protection, and control

    CERN Document Server

    Momoh, James A

    2007-01-01

    * Each Chapter Provides an Introduction, Illustrative Examples, and a SummaryIntroduction to Distribution Automation Systems Historical Background Distribution System Topology and Structure Distribution Automation (DA) and Control Computational Techniques for Distribution Systems Complex Power Concepts Balanced Voltage to Neutral-Connected System Power Relationship for f Y-?-Connected System Per-Unit System Calculation of Power Losses Voltage Regulation Techniques Voltage-Sag Analysis and Calculation Equipment Modeling Components Modeling Distribution System Line Model Distribution Power Flo

  16. Commercialization of the power factor controller

    Science.gov (United States)

    1981-01-01

    The purpose of the Motor Power Controller, also known as the Power Factor Controller, is to improve power factor and reduce power dissipation in induction motors operating below full load. These purposes were studied and tested in detail. The Motor Power Controller is capable of raising power factors from 0.2 to 0.8 and results in energy savings. It was found that many motors, in their present operating applications, are classified as unstable. The electronic nature of the controller vs. the electrical nature of the motor, compound this problem due to the differences in response time of the two devices. Many tests were successfully completed, the most indicating greater savings than anticipated. Also, there was an effect on efficiency which was not included in the calculations.

  17. A Lyapunov theory based UPFC controller for power flow control

    Energy Technology Data Exchange (ETDEWEB)

    Zangeneh, Ali; Kazemi, Ahad; Hajatipour, Majid; Jadid, Shahram [Center of Excellence for Power Systems Automation and Operation, Iran University of Science and Technology, Tehran (Iran)

    2009-09-15

    Unified power flow controller (UPFC) is the most comprehensive multivariable device among the FACTS controllers. Capability of power flow control is the most important responsibility of UPFC. According to high importance of power flow control in transmission lines, the proper controller should be robust against uncertainty and disturbance and also have suitable settling time. For this purpose, a new controller is designed based on the Lyapunov theory and its stability is also evaluated. The Main goal of this paper is to design a controller which enables a power system to track reference signals precisely and to be robust in the presence of uncertainty of system parameters and disturbances. The performance of the proposed controller is simulated on a two bus test system and compared with a conventional PI controller. The simulation results show the power and accuracy of the proposed controller. (author)

  18. Application of Self-adaptive Control in Active Power Filter%自适应控制在有源电力滤波器中的应用

    Institute of Scientific and Technical Information of China (English)

    顾雪晨

    2015-01-01

    自适应控制在工程和科技领域得到了越来越多的应用,当系统存在参数、结构以及环境的不确定因素时,自适应控制提供相应的自适应调节机制,通过调整控制器参数来获得期望的系统特性。本文在总结自适应控制的主要内容的基础上,以有源电力滤波器为例,分析自适应控制原理、设计方法和应用机理。%Self-adaptive control is widely applied in engineering and technology. When uncertain factors such as parameters, structure and operating environment exist, self-adaptive regulating mechanism will be provided correspondingly, and the control parameters can be adjusted automatically. Thus, expected systematic characteristic is obtained. In this paper, the fundamentals of self-adaptive control are concluded with its principle, design method and applying mechanism by taking active power filter as an example.

  19. Laser welding closed-loop power control

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    2003-01-01

    A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser.......A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser....

  20. Laser welding closed-loop power control

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    2003-01-01

    A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser.......A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser....

  1. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Guerrero, Josep M.;

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...... in a distributed way. Real-time hardware-in-the-loop results are presented to verify the proposed control strategy.......This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...

  2. Coordinated Frequency Control of Wind Turbines in Power Systems with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Tarnowski, Germán Claudio

    particular views. These models were developed and verified during this work, basedaround a particular manufacturer’s wind turbine and on said isolated power system withwind power. The capability of variable speed wind turbines for providing Inertial Response is analysed. To perform this assessment, a control...... and the dynamic stability of the grid frequency under large disturbances would be compromised. The aim of this study is to investigate the integration of large scale wind power generation in power systems and its active power control.Novel methods and solutions dealing specifically with the electric frequency...... stability and high wind power penetration or in islanding situations are addressed. The review of relevant theoretical concepts is supported by measurements carried out on an isolated power system characterized by high wind power penetration. Different mathematical and simulation models are used in several...

  3. Coordinated power control of unified power flow controller and its application for enhancing dynamic power system performance

    Science.gov (United States)

    Fang, Wanliang

    This thesis focuses on reporting my research study on a problem area relating to use of Unified Power Flow Controller (UPFC) for coordinating load flow in power systems so as to enhance their static and dynamic performance by having more secure and economical operation and higher dynamic stability margin. UPFC is considered as one of the most promising devices for implementing the Flexible AC Transmission System (FACTS) concept. Although development of UPFC is still on an infant stage, probing into its impact on power system operation is actively pursued and significant effort has been devoted to put it forward as a practical FACTS device and as a challenging academic research object. In order to consider UPFC as a basic power system element, it has to be involved in associated load flow computation essentially for power system control analysis and operational planning. An up front problem for design engineers is therefore pointing to a need to modify existing load flow program so as to accommodate interactions of UPFCs. A lot of research output start coming out but their computational efficiency are not high enough. In this regard, I propose two methods to perform the UPFC embedded load flow calculation to cater for two different types of application. The first one caters for analyzing direct control of load flow on transmission lines with embedded UPFCs. In this type of problem, active and reactive power of the lines, as well as the magnitude of bus voltages are priori given. The load flow solution can then be obtained and enables the UPFC parameters to be determined with a significantly improved computational efficiency. The second one works in contrary to the first one by which parameters of UPFCs are given before hand and the load flow calculation is performed for conforming a feasible operation. It can be regarded as an indirect load flow control calculation which is useful in planning stage for incorporating UPFC into existing system and/or carrying out

  4. Control Architecture for Future Power Systems

    DEFF Research Database (Denmark)

    Heussen, Kai

    This project looks at control of future electric power grids with a high proportion of wind power and a large number of decentralized power generation, consumption and storage units participating to form a reliable supply of electrical energy. The first objective is developing a method...... for assessment of control architecture of electric power systems with a means-ends perspective. Given this purpose-oriented understanding of a power system, the increasingly stochastic nature of this problem shall be addressed and approaches for robust, distributed control will be proposed and analyzed....... The introduction of close-to-real-time markets is envisioned to enable fast distributed resource allocation while guaranteeing system stability. Electric vehicles will be studied as a means of distributed reversible energy storage and a flexible power electronic interface, with application to the case...

  5. Power Preservation Friendly Congestion Control

    Directory of Open Access Journals (Sweden)

    Ittipong Khemapech

    2014-03-01

    Full Text Available Wireless sensor networks (WSNs are an important area with a major technological impact. Power preservation is one of the important issues in communication protocol development for WSNs. This article presents a review of Event-to-Sink Reliable Transport (ESRT which is specifically developed for an event-based WSNs application. Five characteristic regions and corresponding algorithms have been proposed in ESRT. At the end of each cycle, the reliability is observed and the data reporting rate is adjusted accordingly. Two main contributions of this study include an evaluation of the algorithms proposed by ESRT on their capabilities of power preservation and convergence to the optimal state where a sink receives a desired number of received packets and there is no congestion. According to the results, all of the algorithms demonstrate profound reporting rate adjustments. Moreover, both transmitting and receiving powers can be significantly preserved in the case when the sources generated more packets than required and the network is congested. Therefore, the proposed algorithms unlikely require any enhancements. Moreover, ESRT is analysed how well it can fit in some of the existing WSNs applications. The application category which may deploy ESRT is the event detection and tracking where complete reliability is not required.

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

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Hansen, Steffan;

    2008-01-01

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

  7. Modeling Control Situations in Power System Operations

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

    2010-01-01

    Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...

  8. Modeling Control Situations in Power System Operations

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

    2010-01-01

    Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...

  9. Modular supervisory controller for hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Lemos Pereira, A. de

    2000-06-01

    The power supply of remote places has been commonly provided by thermal power plants, usually diesel generators. Although hybrid power systems may constitute the most economical solution in many applications their widespread application to the electrification schemes of remote areas still depends on improvements in the issues of design and operation control. The main limitations of the present hybrid power systems technology, which are identified in this work, are related to the control and supervision of the power system. Therefore this thesis focuses on the modularity of supervisory controllers in order to design cost-competitive and reliable hybrid power systems. The modular supervisory controller created in this project is considered an important part of a system design approach that aims to overcome the technical difficulties of the current engineering practice and contribute to open the market of hybrid power systems. The term modular refers to a set of design characteristics that allows the use of basically the same supervisory controller in different projects. The modularization and standardisation of the controller include several issues such as interfacing components, communication protocols, modelling, programming and control strategies. The modularity can reduce the highly specialised system engineering related to the integration of components, operation and control. It can also avoid the high costs for installation, service and maintenance. A modular algorithm for supervisory controllers has been developed (a Matlab program called SuperCon) using an object-oriented design and it has been tested through several simulations using different hybrid system configurations and different control strategies. This thesis presents a complete control system design process which can be used as the basis for the development and implementation of intelligent and autonomous supervisory controllers for hybrid power systems with modular characteristics. (au)

  10. Power module control moment gyro

    Science.gov (United States)

    1979-01-01

    The directed design modifications to the Skylab/ATM CMG for application to the Power Module include new rotors of a different material with high resistance to stress corrosion cracking. The spin bearing retainer fix which was determined during the post Skylab mission was incorporated, and the speed pickoff was improved through the use of pickoff thermal cycling screening tests. The unlimited gimbal freedom on box axes was incorporated using slip ring assemblies. The on-orbit replacement capability was also incorporated for the CMG assembly and the inverter assembly.

  11. Stability and control of wind farms in power systems

    DEFF Research Database (Denmark)

    Jauch, Clemens

    oscillating power injection can only be realised by controlling the pitch angle.Hence the power system stabiliser of an active-stall turbine is a pitch angle controller. Two different approaches are chosen for designing such a power system stabiliser: a conventional PID controller, and a fuzzy logic...... is part of the project. The mostextensive modelling work deals with the design of the electrical part of the variable speed turbine and its controls. To simulate realistic grid operation the wind turbine models are connected to an aggregated model of the Nordic power system. For thatpurpose the Nordic...... power system model, which was available prior to the project, is extended with a realistic feeder configuration. It is commonly demanded from modern wind turbines, that they must not disconnect in case of transient faults. Therefore,controllers are designed that enable the two turbine types to ride...

  12. Stability and control of wind farms in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Jauch, C.

    2006-10-15

    The Ph.D. project 'Stability and Control of Wind Farms in Power Systems' deals with some selected problems related to wind power in power systems. With increasing wind power penetration, wind turbines substitute the power production of conventional power plants. Therefore, wind turbines also have to take over the power system stabilisation and control tasks, that were traditionally carried out by conventional power plants. Out of the many aspects related to this problem, this project focuses on transient fault ride-through and power system stabilisation. The selection of turbine types considered in this project is limited to active-stall turbines and variable speed, variable pitch turbines with gearboxes and full-scale converter-connected synchronous generators. As a basis for the project, a study into the state of the art is conducted at the beginning of the project. Grid connection requirements that were in force, or published as drafts, at the time, and scientific literature related to the topic, are studied. The project is based on simulations of wind turbines in a power system simulations tool. Some of the models used in this project were readily available prior to the project; the development of others is part of the project. The most extensive modelling work deals with the design of the electrical part of the variable speed turbine and its controls. To simulate realistic grid operation the wind turbine models are connected to an aggregated model of the Nordic power system. For that purpose the Nordic power system model, which was available prior to the project, is extended with a realistic feeder configuration. It is commonly demanded from modern wind turbines, that they must not disconnect in case of transient faults. Therefore, controllers are designed that enable the two turbine types to ride through transient faults. With these transient fault controllers the wind turbines can stay connected to the grid, such that their generation capacity is

  13. Application of PQR Theory for control of a 3-phase 4-wire 4-legs shunt active power filter in the aß?-axes using 3D-SVM technique

    Directory of Open Access Journals (Sweden)

    Ali CHEBABHI

    2015-05-01

    Full Text Available This article discusses and compares two control strategies applied to a 3-phase 4-wire 4-leg shunt active power filter. These two control strategies, including the cross-vector theory called CV theory and the direct method called PQR theory, are based on the instantaneous control of active and reactive power. On one hand, it is shown that, in some cases, cross-vector theory requires elimination of the zero sequence currents in a 3-phase 4-wire 4-leg shunt active power filter, which needs a power storage element, and on the other hand pretreatment system voltage is necessary to obtain compensated sinusoidal current and a degree of freedom. By relying on the cross-vector theory, the PQR theory is used to extract and remove harmonic currents components. In this control technique, there are two internal current control loops and an external voltage control loop, these control loops have been realized by PI controllers when applied 3D-SVM of switching technique. We choose as criteria for comparison the transient and the Total Harmonic Distortion in the line current. A series of simulations in MATLAB/ Simulink environment have been presented and discussed to show the performance of the two control strategies.

  14. Output power control for large wind power penetration in small power system

    Energy Technology Data Exchange (ETDEWEB)

    Senjyu, Tomonobu; Kaneko, Toshiaki; Uehara, Akie; Yona, Atsushi; Sekine, Hideomi [University of the Ryukyus, 1 Senbaru, Nishihara-cho, Nakagami, Okinawa 903-0213 (Japan); Kim, Chul-Hwan [Sungkyunkwan University, Suwon 440-746 (Korea)

    2009-11-15

    Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives of output power leveling and acquisition power increase are achieved. In this control approach, WTG is given output power command by fuzzy reasoning which has three inputs for average wind speed, variance of wind speed, and absolute average of frequency deviation. Since fuzzy reasoning is used, it is possible to define output power command corresponding to wind speed condition and changing capacity of power system momentarily. Moreover, high performance pitch angle control based on output power command is achieved by generalized predictive control (GPC). The simulation results by using actual detailed model for wind power system show the effectiveness of the proposed method. (author)

  15. On load flow control in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Herbig, Arnim

    2000-01-01

    This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this thesis, namely the controlled series capacitor (CSC), the phase angle regulator (PAR), and the unified power flow controller (UPFC). Properties and characteristics of these devices axe investigated and discussed. A simple control strategy is proposed. This strategy is then analyzed extensively. Mathematical methods and physical knowledge about the pertinent phenomena are combined, and it is shown that this control strategy can be used for a fairly general class of devices. Computer simulations of the controlled system provide insight into the system behavior in a system of reasonable size. The robustness and stability of the control system are discussed as are its limits. Further, the behavior of the control strategy in a system where the modeling allows for dynamic phenomena are investigated with computer simulations. It is discussed under which circumstances the control action has beneficial or detrimental effect on the system dynamics. Finally, a graphical approach for analyzing the effect of controllers

  16. Selective harmonic control for power converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede;

    2014-01-01

    This paper proposes an Internal Model Principle (IMP) based Selective Harmonic Controller (SHC) for power converters. The proposed SHC offers an optimal control solution for power converters to mitigate power harmonics. It makes a good trade-off among cost, complexity and performance. It has high...... accuracy and fast transient response, and it is cost-effective, easy for real-time implementation, and compatible for design rules-of-thumb. An application on a three-phase PWM converter has confirmed the effectiveness of the proposed control scheme in terms of harmonic mitigation....

  17. Smart — STATCOM control strategy implementation in wind power plants

    DEFF Research Database (Denmark)

    Sintamarean, Nicolae Christian; Cantarellas, Antoni Mir; Miranda, H.;

    2012-01-01

    converters is increasing. This paper deals with an advanced control strategy design of a three-level converter performing STATCOM and Active Filter functionalities. The proposed system is called Smart-STATCOM since it has the capability of self-controlling reactive power and harmonic voltages at the same......High penetration of wind energy into the grid may introduce stability and power quality problems due to the fluctuating nature of the wind and the increasing complexity of the power system. By implementing advanced functionalities in power converters, it is possible to improve the performance...... of the wind farm and also to provide grid support, as it is required by the grid codes. One of the main compliance difficulties that can be found in such power plants are related to reactive power compensation and to keep the harmonics content between the allowed limits, even if the power of the WPP...

  18. Optimal control applications in electric power systems

    CERN Document Server

    Christensen, G S; Soliman, S A

    1987-01-01

    Significant advances in the field of optimal control have been made over the past few decades. These advances have been well documented in numerous fine publications, and have motivated a number of innovations in electric power system engineering, but they have not yet been collected in book form. Our purpose in writing this book is to provide a description of some of the applications of optimal control techniques to practical power system problems. The book is designed for advanced undergraduate courses in electric power systems, as well as graduate courses in electrical engineering, applied mathematics, and industrial engineering. It is also intended as a self-study aid for practicing personnel involved in the planning and operation of electric power systems for utilities, manufacturers, and consulting and government regulatory agencies. The book consists of seven chapters. It begins with an introductory chapter that briefly reviews the history of optimal control and its power system applications and also p...

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

    Directory of Open Access Journals (Sweden)

    Yogita Kumari

    2015-09-01

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

  20. Multiagent voltage and reactive power control system

    Directory of Open Access Journals (Sweden)

    I. Arkhipov

    2014-12-01

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

  1. Controlled Compact High Voltage Power Lines

    Directory of Open Access Journals (Sweden)

    Postolati V.

    2016-04-01

    Full Text Available Nowadays modern overhead transmission lines (OHL constructions having several significant differences from conventional ones are being used in power grids more and more widely. Implementation of compact overhead lines equipped with FACTS devices, including phase angle regulator settings (compact controlled OHL, appears to be one of the most effective ways of power grid development. Compact controlled AC HV OHL represent a new generation of power transmission lines embodying recent advanced achievements in design solutions, including towers and insulation, together with interconnection schemes and control systems. Results of comprehensive research and development in relation to 110–500kV compact controlled power transmission lines together with theoretical basis, substantiation, and methodological approaches to their practical application are presented in the present paper.

  2. Automated Power Control for Virtualized Infrastructures

    Institute of Scientific and Technical Information of China (English)

    文雨; 王伟平; 郭莉; 孟丹

    2014-01-01

    Power control for virtualized environments has gained much attention recently. One of the ma jor challenges is keeping underlying infrastructure in reasonably low power states and achieving service-level objectives (SLOs) of upper applications as well. Existing solutions, however, cannot effectively tackle this problem for virtualized environments. In this paper, we propose an automated power control solution for such scenarios in hope of making some progress. The major advantage of our solution is being able to precisely control the CPU frequency levels of a physical environment and the CPU power allocations among virtual machines with respect to the SLOs of multiple applications. Based on control theory and online model estimation, our solution can adapt to the variations of application power demands. Additionally, our solution can simultaneously manage the CPU power control for all virtual machines according to their dependencies at either the application-level or the infrastructure-level. The experimental evaluation demonstrates that our solution outperforms three state-of-the-art methods in terms of achieving the application SLOs with low infrastructure power consumption.

  3. A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power filter controlling by nonlinear back stepping controllers.

    Science.gov (United States)

    Chebabhi, Ali; Fellah, Mohammed Karim; Kessal, Abdelhalim; Benkhoris, Mohamed F

    2016-07-01

    In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L-3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK.

  4. Power flow control of intertied ac microgrids

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    of interlinking power converters. Active and reactive power flows of these converters should preferably be managed autonomously without demanding for fast communication links. A scheme that can fulfill the objectives is now proposed, which upon realised, will result in more robustly integrated microgrids...

  5. Power electronic converters modeling and control with case studies

    CERN Document Server

    Bacha, Seddik; Bratcu, Antoneta Iuliana

    2014-01-01

    Modern power electronic converters are involved in a very broad spectrum of applications: switched-mode power supplies, electrical-machine-motion-control, active power filters, distributed power generation, flexible AC transmission systems, renewable energy conversion systems and vehicular technology, among them. Power Electronics Converters Modeling and Control teaches the reader how to analyze and model the behavior of converters and so to improve their design and control. Dealing with a set of confirmed algorithms specifically developed for use with power converters, this text is in two parts: models and control methods. The first is a detailed exposition of the most usual power converter models: ·        switched and averaged models; ·        small/large-signal models; and ·        time/frequency models. The second focuses on three groups of control methods: ·        linear control approaches normally associated with power converters; ·        resonant controllers b...

  6. Facts controllers in power transmission and distribution

    CERN Document Server

    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

  7. Power system dynamics stability and control

    CERN Document Server

    Padiyar, K R

    2008-01-01

    Modern power systems tend to be very Complex not only due to increasing Demand for quality power, but also on Account of extensive interconnections and increasing dependence on control for optimum utilization for existing resources. A good Knowledge of system dynamics and control is Essential for secure operation of the system. This book is intended to serve the needs of the Student and practicing engineers. A Large number of illustrative examples are included to provide an insight into the application of the theory.

  8. Fractional Power Control for Decentralized Wireless Networks

    CERN Document Server

    Jindal, Nihar; Andrews, Jeffrey G

    2007-01-01

    We propose and analyze a new paradigm for power control in decentralized wireless networks, termed fractional power control. Transmission power is chosen as the current channel quality raised to an exponent -s, where s is a constant between 0 and 1. Choosing s = 1 and s = 0 correspond to the familiar cases of channel inversion and constant power transmission, respectively. Choosing s in (0, 1) allows all intermediate policies between these two extremes to be evaluated, and we see that neither extreme is ideal. We prove that using an exponent of s = 1/2 optimizes the transmission capacity of an ad hoc network, meaning that the inverse square root of the channel strength is the optimal transmit power scaling. Intuitively, this choice achieves the optimal balance between helping disadvantaged users while making sure they do not flood the network with interference.

  9. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  10. Technological tendencies for the development and implementation of fault tolerant active controls in combined cycle power plants; Tendencias tecnologicas para el desarrollo e implantacion de controles activos tolerantes a fallas en centrales de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, Marino; Verde R, Cristina [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    This document proposes a methodology that reunites support tools for the operator of a Combined Cycle Generating Power Station allowing him to identify and to classify gas turbine faults, it also reunites some tools for the generation of action advices in the decision making on the operation maneuvers necessary to counteract the effects caused by faults. We are talking about a system implemented in a power station with the reconfiguration of processes and fault arrangement capacities. For this purpose, the line of exhibition delimits first the existing knowledge on automatic control and operations supervision systems in a CCPP and immediately emphasizes the cracks of the system to let pass to the fault tolerant active control system that will detect faults of the gas and steam turbo-generators of a Combined Cycle Generating Power Plant. [Spanish] El presente documento propone una metodologia que reuna herramientas de ayuda al operador de una Central Generadora de Electricidad de Ciclo Combinado para permitirle la identificacion y clasificacion de fallas en las turbinas de gas, asi como herramientas para la generacion de consejos de accion en la toma de decisiones sobre las maniobras de operacion necesarias para contrarrestar los efectos provocados por fallas. Se trata principalmente de un sistema implantado en una central con las capacidades de re-configuracion de procesos y acomodo de fallas. Para esto, la linea de exposicion delimita primero el conocimiento existente sobre sistemas automaticos de control y supervision de operacion en una CGCC y resalta enseguida las grietas del sistema para darle paso al sistema de control activo tolerante a fallas que detectara fallas de los turbogeneradores de gas y vapor de una Central Generadora de Electricidad de Ciclo Combinado.

  11. 有源电力滤波器双滞环电流控制新方法%A novel double hysteresis current control for active power filter

    Institute of Scientific and Technical Information of China (English)

    陈兆岭; 刘国海; 魏明洋

    2013-01-01

    To improve harmonic current tracking performance of shunt active power filter ( APF) based on double hysteresis current control strategy of voltage space vector, a novel 4-level α-β hysteresis comparator was proposed. The control strategy was directly implemented on α-β coordinates. The 4-level α-β hysteresis comparators were inputted current error vectors and outputted 4 state values to determine the location region of current error vectors. The differential relationship between reference voltages and reference currents was discretely calculated to determine the location region of reference voltage vectors. The optimum output switching vector at each instant was selected according to state values output of two 4-le-vel α-β hysteresis comparators and reference voltage vector. The compensatory current error was limited within the hysteresis width. APF models with constant load and variable load were established and simulated by Matlab/Simulink software. The results show that the proposed strategy can efficiently increase the utilization of DC bus with fast response. The total harmonic distortion of power grid current drops from 21.65% to 3. 11% , and the per phase switching number in one power supply cycle decreases from 342 of the conventional hysteresis control to 230 of the proposed method at steady state.%为了提高电压空间矢量双滞环电流控制方法在有源电力滤波器的谐波电流跟踪性能,提出了一种新颖的4段滞环比较器.直接在复平面上实施控制,4段滞环比较器输入误差电流矢量,输出4种状态值,可以确定误差电流矢量的空间分布,而将参考电压与电流之间的微分关系经离散化计算后得到参考电压矢量所在区域.根据两个4段滞环比较器的输出状态值与参考电压矢量的空间分布选择最佳的输出开关矢量,使补偿电流误差控制在滞环宽度以内.采用Matlab/Simulink仿真软件分别对负载不变和突变的情况仿真.结果表

  12. 基于自抗扰的并联有源电力滤波器优化控制策略%An Optimization Control Strategy for Parallel Active Power Filter Based on Active Disturbance Rejection

    Institute of Scientific and Technical Information of China (English)

    童成意; 刘朝华

    2012-01-01

    提出了一种并联型有源滤波器(APF)的自抗扰控制(ADRC)算法,同时利用改进的免疫粒子群算法对自抗扰控制器参数进行全局优化,利用小波变异增强了免疫克隆选择算法的动态优化性能,构建了一种基于免疫粒子群的并联有源电力滤波器自抗扰控制系统.实验结果表明,文中的控制策略不依赖于精确的对象模型,能够有效地抑制高频干扰对APF补偿性能的影响.控制算法能对有源电力滤波器进行有效控制,且具有较好的动态特性和鲁棒性.%The optimal active disturbance rejection control (ADRC) algorithm for paralleling active power filters (APF) is proposed. The improved immune particle swarm algorithm is employed to achieve the global optimization of the active disturbance rejection controller's parameters. The dynamic optimization performance of the immune clonal selection algorithm is further enhanced by the wavelet variation. Based on the immune particle swarm algorithm, a kind of active disturbance rejection control system for parallel APFs is constructed. Experimental results indicate that the proposed control algorithm does not depend on the precise model of controlled plant, and can restrain the negative effect of high frequency interference on the performance of APF compensators. In addition, the effective control for APF is achievable by the proposed algorithm with proved good dynamic characteristic and robustness.

  13. 基于优先顺序法的风电场限出力有功控制策略%Priority List-Based Output-Restricted Active Power Control Strategy for Wind Farms

    Institute of Scientific and Technical Information of China (English)

    林俐; 谢永俊; 朱晨宸; 汪宁渤

    2013-01-01

    With the rapid increase of grid-integrated capacity of wind farms, wind farms should possess the adjusting ability of active power that can control active power output of wind farm according to the command from control center of power grid. Combining with actual requirement for active power control system of clustered wind farms in Jiuquan wind power base in Gansu province, China, taking the utilization of wind energy farthest and the prevention of frequent start/stop of wind power generators as the objectives and based on classical priority list method, an output-restricted active power control strategy for wind farms composed of variable speed constant frequency (VSCF) wind power generators is proposed. To meet the demand on output-restricted control for wind farms, an active power control frame in the level of wind farm and corresponding output-restricted control process are designed. Overall considering the prediction information, operating conditions and control characteristics of wind power generation units within wind farms, an output-restricted active power control sequence for wind farms, in which the indices of control performances of wind power generation units are taken as the index for rank ordering, is established, and then, based on the control sequence the method to allocate output-restricted active power is given. The correctness and effectiveness of the proposed control strategy are verified by the calculation of a wind farm composed of 33 doubly fed induction generators.%  随着风电并网容量的增加,风电场应具备有功功率调节能力,能根据电网调度部门指令控制其有功功率输出。结合甘肃酒泉风电基地集群风电有功控制系统的实际需要,以实现最大风能利用、避免风电场频繁起停为目标,基于经典优先顺序法提出了一种应用于变速恒频风电场的限出力有功控制策略。针对风电场限出力控制需要,设计了风电场层有功

  14. Modelling supervisory controller for hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.; Bindner, H.; Lundsager, P. [Risoe National Lab., Roskilde (Denmark); Jannerup, O. [Technical Univ. of Denmark, Dept. of Automation, Lyngby (Denmark)

    1999-03-01

    Supervisory controllers are important to achieve optimal operation of hybrid power systems. The performance and economics of such systems depend mainly on the control strategy for switching on/off components. The modular concept described in this paper is an attempt to design standard supervisory controllers that could be used in different applications, such as village power and telecommunication applications. This paper presents some basic aspects of modelling and design of modular supervisory controllers using the object-oriented modelling technique. The functional abstraction hierarchy technique is used to formulate the control requirements and identify the functions of the control system. The modular algorithm is generic and flexible enough to be used with any system configuration and several goals (different applications). The modularity includes accepting modification of system configuration and goals during operation with minor or no changes in the supervisory controller. (au)

  15. Overview on the power supply systems for plasma instabilities control

    Energy Technology Data Exchange (ETDEWEB)

    Toigo, V., E-mail: vanni.toigo@igi.cnr.it [Consorzio RFX - EURATOM - ENEA Association, C.so Stati Uniti 4, 35127 Padova (Italy); Gaio, E.; Piovan, R.; Barp, M.; Bigi, M.; Ferro, A.; Finotti, C.; Novello, L.; Recchia, M.; Zamengo, A.; Zanotto, L. [Consorzio RFX - EURATOM - ENEA Association, C.so Stati Uniti 4, 35127 Padova (Italy)

    2011-10-15

    The paper presents an overview on the power supply (PS) systems for plasma instabilities control in fusion experiments, based on active control coils. First, the MHD instabilities and the approach to their control in Tokamaks and Reversed Field Pinches (RFPs) are described. Then, the features of MHD modes controls presently used in fusion experiments are reviewed. For the control systems based on active coils fed by fast power supplies, the typical requirements in terms of power, dynamics, accuracy and delay are summarized and discussed. Then, a survey on the technology available to design these types of PSs is given, together with the most suitable circuit topologies and guidelines for the design, on the basis of solutions adopted in existing experiments.

  16. Power System Security and Stability Control Company

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Branch Company Profile Power System Security and Stability Control Company is called "NARI Stability" to externals. It has a scientific research team, led by Prof. Yusheng Xue, who is an international renowned expert on stability technology, and an academician of the Chinese Academy of Engineering. Based on support and service of security and stability control technology and equipment,

  17. Activities of the control services; Activites des services du controle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper summarizes the control activities of the technical service of electric power and big dams: annual examinations, administrative instructions (draining, floods, granting renewal), decennial examinations etc. (J.S.)

  18. Model-based predictive direct power control of brushless doubly fed reluctance generator for wind power applications

    Directory of Open Access Journals (Sweden)

    Maryam Moazen

    2016-09-01

    Full Text Available In this paper, a predictive direct power control (PDPC method for the brushless doubly fed reluctance generator (BDFRG is proposed. Firstly, the BDFRG active and reactive power equations are derived and then the active and reactive power variations have been predicted within a fixed sampling period. The predicted power variations are used to calculate the required voltage of the secondary winding so that the power errors at the end of the following sampling period are eliminated. Switching pulses are produced using space vector pulse width modulation (SVPWM approach which causes to a fixed switching frequency. The BDFRG model and the proposed control method are simulated in MATLAB/Simulink software. Simulation results indicate the good performance of the control system in tracking of the active and reactive power references in both power step and speed variation conditions. In addition, fast dynamic response and lower output power ripple are other advantages of this control method.

  19. Chaotic dynamics of controlled electric power systems

    Science.gov (United States)

    Kozlov, V. N.; Trosko, I. U.

    2016-12-01

    The conditions for appearance of chaotic dynamics of electromagnetic and electromechanical processes in energy systems described by the Park-Gorev bilinear differential equations with account for lags of coordinates and restrictions on control have been formulated. On the basis of classical equations, the parameters of synchronous generators and power lines, at which the chaotic dynamics of energy systems appears, have been found. The qualitative and quantitative characteristics of chaotic processes in energy associations of two types, based on the Hopf theorem, and methods of nonstationary linearization and decompositions are given. The properties of spectral characteristics of chaotic processes have been investigated, and the qualitative similarity of bilinear equations of power systems and Lorentz equations have been found. These results can be used for modernization of the systems of control of energy objects. The qualitative and quantitative characteristics for power energy systems as objects of control and for some laws of control with the feedback have been established.

  20. Power and Frequency Control of Induction Furnace Using Fuzzy Logic Controller

    OpenAIRE

    Sinafar, Behzad; Ghiasi, Amir Rikhtegar

    2015-01-01

    This paper introduces a new method to control resonance frequency and output power of induction heating coil. Induction heating coil can be controlled by single phase sinusoidal pulse width modulation (SPWM) inverter .All electrical requirements beside magnetic permeability and resistivity variation for modeling induction heating coil have been considered to make simulations practical .Control blocks using Fuzzy logic which control both active and reactive power have been designed .The system...

  1. Wireless Power Control for Tactical MANET: Power Rate Bounds

    Science.gov (United States)

    2016-09-01

    Allen David F. Schwartz Approved for public release. . SSC Pacific San Diego , CA 92152-5001 SB SSC Pacific San Diego ...and Naval Warfare Systems Center Pacific (SSC Pacific), San Diego , CA. Funding for this effort was provided by the SSC Pacific Naval Innovative...Delgado & Luna- Rivera ob- serve [7]: 5 “Therefore, the main challenge in distributed power control is to compensate the time-varying profiles of the

  2. Adaptive Fuzzy Control for Power-Frequency Characteristic Regulation in High-RES Power Systems

    Directory of Open Access Journals (Sweden)

    Evangelos Rikos

    2017-07-01

    Full Text Available Future power systems control will require large-scale activation of reserves at distribution level. Despite their high potential, distributed energy resources (DER used for frequency control pose challenges due to unpredictability, grid bottlenecks, etc. To deal with these issues, this study presents a novel strategy of power frequency characteristic dynamic adjustment based on the imbalance state. This way, the concerned operators become aware of the imbalance location but also a more accurate redistribution of responsibilities in terms of reserves activations is achieved. The proposed control is based on the concept of “cells” which are power systems with operating capabilities and responsibilities similar to control areas (CAs, but fostering the use of resources at all voltage levels, particularly distribution grids. Control autonomy of cells allows increased RES hosting. In this study, the power frequency characteristic of a cell is adjusted in real time by means of a fuzzy controller, which curtails part of the reserves, in order to avoid unnecessary deployment throughout a synchronous area, leading to a more localised activation and reducing losses, congestions and reserves exhaustion. Simulation tests in a four-cell reference power system prove that the controller significantly reduces the use of reserves without compromising the overall stability.

  3. Maximum power point tracking control with active disturbance rejection controller based on the best tip speed ratio%最佳叶尖速比的最大功率自抗扰跟踪控制

    Institute of Scientific and Technical Information of China (English)

    李娟; 张克兆; 李生权; 刘超

    2015-01-01

    Considering the permanent magnet synchronous wind generator system with uncertainties, multi interferences and low efficiency, a maximum power point tracking with active disturbance rejection control strategy based on the best tip speed ratio was proposed to track the motor speed real time and to capture the maximum power. The active disturbance rejection controller does not depend on the mathematical model of the system. The uncertainties including nonlinear, strong coupling, parameter variations and ex-ternal disturbances wer lumped to the total disturbances of system, which affect the tracking speed in real time. The extended state observer estimates the total disturbances, and then compensates them through the feedback controller, which improves the speed tracking ability. Simulation results show that, com-pared with the traditional PI control method, the proposed control strategy not only guarantees the system to achieve maximum power output, but also has strong robustness against uncertain dynamics and external disturbances.%针对永磁同步风力发电系统中存在的不确定、多干扰、效率低等问题,提出一种以实现最大功率跟踪控制为目标,实时跟踪电机转速的基于最佳叶尖速比的自抗扰控制策略. 该方法不依赖于系统数学模型,将永磁同步风力发电机存在的、影响转速难以实时跟踪的非线性、强耦合、参数变化、外界干扰等不确定性看成系统总干扰. 通过扩张状态观测器对系统的总干扰进行估计,然后通过反馈控制器进行干扰补偿,从而提高转速的跟踪能力. 仿真结果表明,与传统的PI控制方法相比,自抗扰控制不仅能保证系统实现最大功率输出,而且提高了系统的鲁棒性和抗干扰性能.

  4. Optimal coordinated voltage control of power systems

    Institute of Scientific and Technical Information of China (English)

    LI Yan-jun; HILL David J.; WU Tie-jun

    2006-01-01

    An immune algorithm solution is proposed in this paper to deal with the problem of optimal coordination of local physically based controllers in order to preserve or retain mid and long term voltage stability. This problem is in fact a global coordination control problem which involves not only sequencing and timing different control devices but also tuning the parameters of controllers. A multi-stage coordinated control scheme is presented, aiming at retaining good voltage levels with minimal control efforts and costs after severe disturbances in power systems. A self-pattern-recognized vaccination procedure is developed to transfer effective heuristic information into the new generation of solution candidates to speed up the convergence of the search procedure to global optima. An example of four bus power system case study is investigated to show the effectiveness and efficiency of the proposed algorithm, compared with several existing approaches such as differential dynamic programming and tree-search.

  5. Reasoning about Control Situations in Power Systems

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten

    2009-01-01

    Introduction of distributed generation, deregulation and distribution of control has brought new challenges for electric power system operation, control and automation. Traditional power system models used in reasoning tasks such as intelligent control are highly dependent on the task purpose. Thus......, a model for intelligent control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because...... of the lack of explicit principles for model construction. Available modeling concepts for intelligent control do not assist the model builder in the selection of model content i.e. in deciding what is relevant to represent for a particular reasoning task and thereby faced with a difficult interpretation...

  6. Adaptive Power Control for Space Communications

    Science.gov (United States)

    Thompson, Willie L., II; Israel, David J.

    2008-01-01

    This paper investigates the implementation of power control techniques for crosslinks communications during a rendezvous scenario of the Crew Exploration Vehicle (CEV) and the Lunar Surface Access Module (LSAM). During the rendezvous, NASA requires that the CEV supports two communication links: space-to-ground and crosslink simultaneously. The crosslink will generate excess interference to the space-to-ground link as the distances between the two vehicles decreases, if the output power is fixed and optimized for the worst-case link analysis at the maximum distance range. As a result, power control is required to maintain the optimal power level for the crosslink without interfering with the space-to-ground link. A proof-of-concept will be described and implemented with Goddard Space Flight Center (GSFC) Communications, Standard, and Technology Lab (CSTL).

  7. The CERN Control Protocol for power converters

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, I.; Benincasa, G.; Berrig, O.; Brun, R.; Burla, P.; Coudert, G.; Pett, J.G.; Pittin, R.; Royer, J.P.; Trofimov, N. (CERN, Geneva (Switzerland))

    1993-08-01

    The Control Protocols provide, for a class of similar devices, a unique and standard access procedure from the control system. Behavioral models have been proposed for the different kinds of Power Converters and the corresponding functionalities, with their parameters, variables and attributes have been identified. The resulting data structures have been presented using the ISO ASN.1 metalanguage, that permits universal representation independent of any computer environment. Implementations in the UNIX-based CERN accelerator control systems are under development.

  8. Design and Control of a Powered Transfemoral Prosthesis.

    Science.gov (United States)

    Sup, Frank; Bohara, Amit; Goldfarb, Michael

    2008-02-01

    The paper describes the design and control of a transfemoral prosthesis with powered knee and ankle joints. The initial prototype is a pneumatically actuated powered-tethered device, which is intended to serve as a laboratory test bed for a subsequent self-powered version. The prosthesis design is described, including its kinematic optimization and the design of a three-axis socket load cell that measures the forces and moments of interaction between the socket and prosthesis. A gait controller is proposed based on the use of passive impedance functions that coordinates the motion of the prosthesis with the user during level walking. The control approach is implemented on the prosthesis prototype and experimental results are shown that demonstrate the promise of the active prosthesis and control approach in restoring fully powered level walking to the user.

  9. Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

    Institute of Scientific and Technical Information of China (English)

    CUI Yu-long; LIU Hong; WANG Jing-qin; SUN Shu-guang

    2007-01-01

    This paper first discusses the operating principle ofinstantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyfistor bridge rectifier circuit is constructed.The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

  10. Analysis of Control Power in Controlled Remote State Preparation Schemes

    Science.gov (United States)

    Li, Xihan; Ghose, Shohini

    2017-03-01

    We quantify and analyze the controller's power in controlled remote state preparation schemes. Our analysis provides a lower bound on the control power required for controlled remote preparation of arbitrary D-dimensional states. We evaluate several existing controlled remote state preparation protocols and show that some proposed non-maximally entangled channels are not suitable for perfect controlled remote preparation of arbitrary quantum states from the controller's point of view. We find that for remotely preparing D-dimensional states, the entropy of each controller should be no less than log2 D bits. Our new criteria are not only useful for evaluating controlled remote state preparation schemes but can also be used for other controlled quantum communication schemes.

  11. Power and Control in Kathmandu: A Comparison of Attempted Power, Actual Power, and Achieved Power.

    Science.gov (United States)

    Emery, Clifton R; Thapa, Sirjana; Wu, Shali

    2016-05-05

    We argue that the concept of power has been inadvertently sidelined in recent theory and research on husband violence. Three types of relationship power may matter with respect to husband violence: attempted power, actual power, and achieved power. Analyses of a randomly selected representative sample of 270 married or partnered women in Kathmandu showed that actual power was related to husband violence prevalence, severity, and injury. Achieved power was related to husband violence prevalence and severity, and attempted power was related to husband violence injury. Implications are discussed.

  12. Power control electronics for cryogenic instrumentation

    Science.gov (United States)

    Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

    1995-01-01

    In order to achieve a high-efficiency high-density cryogenic instrumentation system, the power processing electronics should be placed in the cold environment along with the sensors and signal-processing electronics. The typical instrumentation system requires low voltage dc usually obtained from processing line frequency ac power. Switch-mode power conversion topologies such as forward, flyback, push-pull, and half-bridge are used for high-efficiency power processing using pulse-width modulation (PWM) or resonant control. This paper presents several PWM and multiresonant power control circuits, implemented using commercially available CMOS and BiCMOS integrated circuits, and their performance at liquid-nitrogen temperature (77 K) as compared to their room temperature (300 K) performance. The operation of integrated circuits at cryogenic temperatures results in an improved performance in terms of increased speed, reduced latch-up susceptibility, reduced leakage current, and reduced thermal noise. However, the switching noise increased at 77 K compared to 300 K. The power control circuits tested in the laboratory did successfully restart at 77 K.

  13. Junction temperature measurements via thermo-sensitive electrical parameters and their application to condition monitoring and active thermal control of power converters

    DEFF Research Database (Denmark)

    Baker, Nick; Liserre, Marco; Dupont, L.

    2013-01-01

    implementation of active thermal control to reduce losses and increase lifetime can be performed given an accurate knowledge of temperature. Temperature measurements via thermo-sensitive electrical parameters (TSEP) are one way to carry out immediate temperature readings on fully packaged devices. However...... scale implementation of these methods are discussed. Their potential use in the aforementioned goals in condition monitoring and active thermal control is also described....

  14. Abdicating power for control: a precision timing strategy to modulate function of flight power muscles.

    Science.gov (United States)

    Sponberg, S; Daniel, T L

    2012-10-07

    Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power-phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left-right pairs of flight muscles normally fire precisely, within 0.5-0.6 ms of each other; (ii) during a yawing optomotor response, left-right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left-right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left-right timing differences. Because many organisms also have muscles operating with high power-phase gains (Δ(power)/Δ(phase)), this motor control strategy may be ubiquitous in locomotor systems.

  15. Control algorithms for control of real and reactive power flows and power oscillation damping using UPFC

    Energy Technology Data Exchange (ETDEWEB)

    Ilango, G. Saravana; Nagamani, C.; Sai, A.V.S.S.R.; Aravindan, D. [Department of Electrical and Electronics Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India)

    2009-04-15

    This paper investigates the application of multivariable control technique to multi-input multi-output (MIMO) non-linear problem of a power transmission system with UPFC. The main objective is to achieve effective independent control of real and reactive power flows with zero dynamic interactions. Towards achieving the objective, feed-back linearization control (FBLC) scheme is implemented in the laboratory for the control of UPFC. A two-bus power system with UPFC has been built in laboratory and the control implementation has been carried out using DSP TMS320LF2407A. Both power flow control and power oscillation damping issues are addressed. The excellent correlation between simulation and experimental results using a laboratory test system establish the validity of the proposed scheme. Although the power stage of the developed laboratory system is a scaled down model and has limited ratings, the FBLC controller can be used equally effectively in a more realistic system set up by appropriate scaling factors for the fed-back signals of currents and voltages and for initiating the inverter voltages. The proposed controller enables UPFC to independently control the real and reactive power with absolute decoupling. Also it is found that the overall performance of the system with the proposed controller is far superior to that using conventional cascade PI control structure. (author)

  16. Improving Advanced Inverter Control Convergence in Distribution Power Flow

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, Adarsh; Palmintier, Bryan; Ding, Fei; Mather, Barry; Baggu, Murali

    2016-11-21

    Simulation of modern distribution system powerflow increasingly requires capturing the impact of advanced PV inverter voltage regulation on powerflow. With Volt/var control, the inverter adjusts its reactive power flow as a function of the point of common coupling (PCC) voltage. Similarly, Volt/watt control curtails active power production as a function of PCC voltage. However, with larger systems and higher penetrations of PV, this active/reactive power flow itself can cause significant changes to the PCC voltage potentially introducing oscillations that slow the convergence of system simulations. Improper treatment of these advanced inverter functions could potentially lead to incorrect results. This paper explores a simple approach to speed such convergence by blending in the previous iteration's reactive power estimate to dampen these oscillations. Results with a single large (5MW) PV system and with multiple 500kW advanced inverters show dramatic improvements using this approach.

  17. Simple Activities for Powerful Impact

    Science.gov (United States)

    LaConte, K.; Shupla, C. B.; Dusenbery, P.; Harold, J. B.; Holland, A.

    2016-12-01

    STEM education is having a transformational impact on libraries across the country. The STAR Library Education Network (STAR_Net) provides free Science-Technology Activities & Resources that are helping libraries to engage their communities in STEM learning experiences. Hear the results of a national 2015 survey of library and STEM professionals and learn what STEM programming is currently in place in public libraries and how libraries approach and implement STEM programs. Experience hands-on space science activities that are being used in library programs with multiple age groups. Through these hands-on activities, learners explore the nature of science and employ science and engineering practices, including developing and using models, planning and carrying out investigations, and engaging in argument from evidence (NGSS Lead States, 2013). Learn how STAR_Net can help you print (free!) mini-exhibits and educator guides. Join STAR_Net's online community and access STEM resources and webinars to work with libraries in your local community.

  18. Current limiting remote power control module

    Science.gov (United States)

    Hopkins, Douglas C.

    1990-01-01

    The power source for the Space Station Freedom will be fully utilized nearly all of the time. As such, any loads on the system will need to operate within expected limits. Should any load draw an inordinate amount of power, the bus voltage for the system may sag and disrupt the operation of other loads. To protect the bus and loads some type of power interface between the bus and each load must be provided. This interface is most crucial when load faults occur. A possible system configuration is presented. The proposed interface is the Current Limiting Remote Power Controller (CL-RPC). Such an interface should provide the following power functions: limit overloading and resulting undervoltage; prevent catastrophic failure and still provide for redundancy management within the load; minimize cable heating; and provide accurate current measurement. A functional block diagram of the power processing stage of a CL-RPC is included. There are four functions that drive the circuit design: rate control of current; current sensing; the variable conductance switch (VCS) technology; and the algorithm used for current limiting. Each function is discussed separately.

  19. A New Real Time Lyapunov Based Controller for Power Quality Improvement in Unified Power Flow Controllers Using Direct Matrix Converters

    Directory of Open Access Journals (Sweden)

    Joaquim Monteiro

    2017-06-01

    Full Text Available This paper proposes a Direct Matrix Converter operating as a Unified Power Flow Controller (DMC-UPFC with an advanced control method for UPFC, based on the Lyapunov direct method, presenting good results in power quality assessment. This control method is used for real-time calculation of the appropriate matrix switching state, determining which switching state should be applied in the following sampling period. The control strategy takes into account active and reactive power flow references to choose the vector converter closest to the optimum. Theoretical principles for this new real-time vector modulation and control applied to the DMC-UPFC with input filter are established. The method needs DMC-UPFC dynamic equations to be solved just once in each control cycle, to find the required optimum vector, in contrast to similar control methods that need 27 vector estimations per control cycle. The designed controller’s performance was evaluated using Matlab/Simulink software. Controllers were also implemented using a digital signal processing (DSP system and matrix hardware. Simulation and experimental results show decoupled transmission line active (P and reactive (Q power control with zero theoretical error tracking and fast response. Output currents and voltages show small ripple and low harmonic content.

  20. Power Quality Improvement Using Hybrid Power Flow Controller in Power System

    Directory of Open Access Journals (Sweden)

    Manidhar Thula ,

    2014-01-01

    Full Text Available This paper discusses the applicability of Hybrid Power Flow Controller (HPFC as an alternative to Unified Power Flow Controller (UPFC for improvement of power system performance. UPFC is a flexible AC transmission system (FACTS device containing two switching converters, one in series and one in shunt. To configure the HPFC, one of the switching converters of the UPFC is replaced by thyristor controlled variable impedances, thus reducing the cost. In this paper, the HPFC has been configured by multilevel Voltage Source Converter (VSC used for the shunt compensation branches and a thyristor controlled variable impedance used for series compensation. It is shown that with suitable control the HPFC can inject a voltage of required magnitude in series with the line at any desired angle, just like UPFC. This helps in providing compensation equivalent to UPFC and improving the steady state stability limits of the power system.

  1. Interventional placement of thin coil shaped implants powered wirelessly for monitoring vital signals and controlling abnormal activities by electro-stimulation.

    Science.gov (United States)

    Ohta, Hidetoshi; Honda, Masanobu; Takamiya, Makoto

    2016-08-01

    Various types of implants are being commonly used for monitoring vital signals and controlling the critically ill patient's condition such as arrhythmia, sick sinus syndrome, etc. For implanting these medical devices under the skin, surgery is inevitable. These days many patients are more willing to accept interventional therapies that are less invasive, especially inserting a catheter into a blood vessel or endoscopy through a natural orifice. To be able to use interventional therapy for implanting medical devices, they will need to be small enough to fit them through a catheter or the forceps channel of an endoscope. We evaluated a wirelessly powered prototype of a thin coil shaped (diameter 0.05 inches) implant for electrocardiogram (ECG) monitoring and controlling abnormal heart rhythms. An extracorporeal unit fed power to the sensors and transceiver circuit. We are planning to add sensors for detecting ECG signals and also a pulse generator for transmitting signals to the heart. At 13.6MHz, 10mW was wirelessly transferred from the helical antenna attached to the chest wall of the phantom to the coil's receiving antenna and the power enabled the sensors and circuits to work. Moreover, the coil's receiving antennas worked as stimulating electrodes similar to a pacemaker lead.

  2. Active Disturbances Rejection Control of Wind Power System Based on Direct Driving PMSG%基于直驱型PMSG风力发电系统的变桨自抗扰控制

    Institute of Scientific and Technical Information of China (English)

    朱必刚

    2011-01-01

    为了实现大功率风力发电系统的恒功率控制,首先建立了基于直驱型PMSG风力发电系统的数学模型;其次,以功率偏差为控制器的输入信号,设计了一种基于自抗扰算法的风力发电系统变桨距控制器.最后,在阵风叠加随机风的作用下进行仿真研究.仿真结果表明,该控制器能够有效地控制桨距角,可以实现额定风速以上时系统输出功率的恒定.%In order to realize the constant power output of high-power wind generating systems, the mathematic model of a wind generating system based on direct driving PMSG is established. Taking the power deviation as the control input signal, a variable-pitch controller based on an active disturbances rejection algorithm was designed for wind generating systems to control the pitch angle of the wind power system. The simulation was undertaken under random wind. The simulation results indicate that the controller can effectively control the pitch angle and realize the goal of constant power output of the system when the wind exceeds the rated wind velocity.

  3. Research on Power Control of Wind Power Generation Based on Neural Network Adaptive Control

    Institute of Scientific and Technical Information of China (English)

    Hai-ying DONG; Chuan-hua SUN

    2010-01-01

    -For the characteristics of wind power generation system is multivariable,nonlinear and random,in this paper the neural network PID adaptive control is adopted.The size of pitch angle is adjusted in time to improve the performance of power control.The PID parameters are corrected by the gradient descent method,and Radial Basis Functinn(RBF)neural network is used as the system identifier in this method.Simulation results shaw that by using neural adaptive PID controller the generator power control can inhibit effectively the speed and affect the output power of generator.The dynamic performance and robustness of the controlled system is good,and the performance of wind power system is improved.

  4. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas

    2010-08-15

    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  5. Active noise control primer

    CERN Document Server

    Snyder, Scott D

    2000-01-01

    Active noise control - the reduction of noise by generating an acoustic signal that actively interferes with the noise - has become an active area of basic research and engineering applications. The aim of this book is to present all of the basic knowledge one needs for assessing how useful active noise control will be for a given problem and then to provide some guidance for designing, setting up, and tuning an active noise-control system. Written for students who have no prior knowledge of acoustics, signal processing, or noise control but who do have a reasonable grasp of basic physics and mathematics, the book is short and descriptive. It leaves for more advanced texts or research monographs all mathematical details and proofs concerning vibrations, signal processing and the like. The book can thus be used in independent study, in a classroom with laboratories, or in conjunction with a kit for experiment or demonstration. Topics covered include: basic acoustics; human perception and sound; sound intensity...

  6. Model predictive control for wind power gradients

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Boyd, Stephen; Jørgensen, John Bagterp

    2015-01-01

    ranges. The system dynamics are quite non-linear, and the constraints and objectives are not convex functions of the control inputs, so the resulting optimal control problem is difficult to solve globally. In this paper, we show that by a novel change of variables, which focuses on power flows, we can......We consider the operation of a wind turbine and a connected local battery or other electrical storage device, taking into account varying wind speed, with the goal of maximizing the total energy generated while respecting limits on the time derivative (gradient) of power delivered to the grid. We...... transform the problem to one with linear dynamics and convex constraints. Thus, the problem can be globally solved, using robust, fast solvers tailored for embedded control applications. We implement the optimal control problem in a receding horizon manner and provide extensive closed-loop tests with real...

  7. Powering hydrothermal activity on Enceladus

    Science.gov (United States)

    Tobie, Gabriel; Choblet, Gael; Sotin, Christophe; Behounkova, Marie; Cadek, Ondrej; Postberg, Frank; Soucek, Ondrej

    2017-04-01

    A series of evidence gathered by the Cassini spacecraft indicates that the intense activity at the South Pole of Saturn's moon Enceladus is related to a subsurface salty water reservoir associated with seafloor hydrothermal activity (Hsu et al. 2015, Waite et al. 2017). The observation of an elevated libration implies that this reservoir is global with a thin ice shell (20-25 km in average (Thomas et al. 2016) and 90 °C) mostly in the polar regions, explaining strongly localized ice shell thinning. Owing to strong dissipation in Saturn (Lainey et al. 2017), we show that circulation of hot waters in the core may last at least 20-25 million years and that 10 to 100% of the oceanic volume may be processed in the core at temperature higher than 90°C on this timescale. Whether this has been sufficient for the emergence of life can be explored by future spacecraft missions (Mitri et al., this meeting; Lunine et al. 2017).

  8. Exact Power Constraints in Smart Grid Control

    DEFF Research Database (Denmark)

    Trangbæk, K; Petersen, Mette Højgaard; Bendtsen, Jan Dimon

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The objective is to accommodate load variations on the grid, arising from varying consumption and natural variations in the power production e.g. from wind turbines. This balancing between supply and demand...... is performed by distributing power to consumers in an optimal manner, subject to the requirement that each consumer receives the specific amount of energy the consumer is entitled to within a specific time horizon. However, in order to do so, the high-level controller requires knowledge of how much energy...... consumer models. The example illustrates that the exact bounds computed by the proposed method leads to a better power distribution than a conventional, conservative approach in case of fast changes in the load....

  9. Novel deadbeat power control strategy for grid connected systems

    Directory of Open Access Journals (Sweden)

    Yousry Atia

    2015-09-01

    Full Text Available This paper introduces a novel approach for power control of three phase voltage source inverter (VSI in grid connected distribution generation system. In this approach, the control of active and reactive power is based on deadbeat control strategy. First, the difference between the reference and actual currents are introduced in different approach. Then current to power substitutions are carried out to obtain direct relationship between the required inverter voltage and instantaneous power errors. There is no need for coordinate transformation or PLL, where the required inverter voltage vector calculations carried out in α–β stationary reference frame. The proposed technique introduces two cross coupling components in the control function. Including these two components, the controller can achieve nearly zero steady-state tracking error of the controlled variables. To obtain fixed switching frequency operations, space vector modulation (SVM is used to synthesize the required inverter voltage vector and to generate the switching pulses for the VSI. The proposed strategy has the simplicity of the direct power control (DPC technique and doesn’t require any current control loops. The proposed strategy is experimentally implemented using fixed-point microcontroller. Simulation and experimental results are presented to confirm the superiority of the proposed strategy.

  10. Reactive power compensation of wind energy conversion system by using Unified Power Flow Controller

    Energy Technology Data Exchange (ETDEWEB)

    Dizdarevic, N.; Majstrovic, M. [Energy Inst. Hrvoje Pozar, Zagreb (Croatia); Andersson, G. [ETH-Zentrum, Zurich (Switzerland). Power Systems Lab.

    2005-07-01

    Voltage control and reactive power compensation in a distribution network with embedded Wind Energy Conversion System (WECS) represents the main concern of this paper. The WECS is a fixed speed/constant frequency system that is equipped with an induction generator driven by an unregulated wind turbine. The problem is viewed from short-term (10 seconds), mid-term (10 minutes) and long-term (48 hours) time domain responses of the system to different changes of wind speed and load daily cycles. Being disturbed by a variable wind speed, the WECS injects variable active and reactive power into the distribution network exposing nearby consumers to excessive voltage changes. In the FACTS-based solution approach, the Unified Power Flow Controller (UPFC) is used at the point of the WECS network connection to help solve technical issues related to voltage support and series reactive power flow control. (Author)

  11. Power-based control of physical systems

    NARCIS (Netherlands)

    Garcia-Canseco, Eloisa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M. A.

    2010-01-01

    It is well known that energy-balancing control is stymied by the presence of pervasive dissipation. To overcome this problem in electrical circuits, the alternative paradigm of power shaping was introduced in Ortega, Jeltsema, and Scherpen (2003)-where, as suggested by its name, stabilization is ach

  12. Power, Control and Status in Physical Education.

    Science.gov (United States)

    Thomson, Ian

    2003-01-01

    For most of the 20th century, Scottish teacher education in physical education, sport, and recreation were divided by gender and philosophy and provided by two specialist colleges. Analysis of the government's 1986 decision to merge the colleges focuses on the shift in power and control from the self-contained world of physical education to…

  13. Exact Power Constraints in Smart Grid Control

    DEFF Research Database (Denmark)

    Trangbæk, K; Petersen, Mette Højgaard; Bendtsen, Jan Dimon

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The objective is to accommodate load variations on the grid, arising from varying consumption and natural variations in the power production e.g. from wind turbines. This balancing between supply and demand...

  14. Bidirectional control system for energy flow in solar powered flywheel

    Science.gov (United States)

    Nola, Frank J. (Inventor)

    1987-01-01

    An energy storage system for a spacecraft is provided which employs a solar powered flywheel arrangement including a motor/generator which, in different operating modes, drives the flywheel and is driven thereby. A control circuit, including a threshold comparator, senses the output of a solar energy converter, and when a threshold voltage is exceeded thereby indicating the availability of solar power for the spacecraft loads, activates a speed control loop including the motor/generator so as to accelerate the flywheel to a constant speed and thereby store mechanical energy, while also supplying energy from the solar converter to the loads. Under circumstances where solar energy is not available and thus the threshold voltage is not exceeded, the control circuit deactivates the speed control loop and activates a voltage control loop that provides for operation of the motor as a generator so that mechanical energy from the flywheel is converted into electrical energy for supply to the spacecraft loads.

  15. 有源电力滤波器降低容量控制策略研究%Study on Control Strategy of Active Power Filter in Capacitance Minimizing

    Institute of Scientific and Technical Information of China (English)

    颜文旭; 纪志成; 谢林柏

    2012-01-01

    Shunt Active Power Filter ( APF) provides a way of harmonics suppression and reactive compensation for power systems, and its capacitance is identified as a very important factor for its application in the traditional power systems by power capacitors reactive power compensation. By analyzing the energy flows of APF and the key factors of APF capacitance, a novel control strategy is presented. While in the condition of power voltage distortion, the referenced compensation currents contains the fundamental active power and reactive power are achieved in model of power currents sinusoidal and APF capacitance minimized. An improved detection method for the fundamental positive sequence is put forward, which is applied in realizing the control strategy that decreases the APF currents and its loss, and then improves the efficiency. Simulations and experimental results indicate that the proposed control strategy has satisfactory performance in minimizing APF capacitance. It can be used to reduce the size of APF and potentially suppress harmonics in the traditional power distribution with reactive power compensation by power capacitors.%对有源电力滤波器(APF)能量流进行分析,得出决定APF容量的基本要素.针对复杂电源环境下APF的补偿目标,提出一种基于电源电流基波正弦化的降低容量控制策略,获取负载电流中的基波有功功率及基波无功功率,并获得补偿参考电流.为实现控制策略,提出适用于电源电压畸变情况下的三相电压基波正序检测的改进方法,减小APF变流电路总电流和自身损耗,提高了APF的效率.仿真和实验结果验证了该控制策略的正确性和有效性,对并联型APF的小型化及电力系统滤波改造具有实用的参考价值.

  16. Low Power CMOS Digitally Controlled Oscillator

    Directory of Open Access Journals (Sweden)

    Sujata Pandey,

    2010-08-01

    Full Text Available Here, two new designs of CMOS digitally controlled oscillators (DCO for low power application have been proposed. First design has been implemented with one driving strength controlled delay cell and withtwo NAND gates used as inverters. The second design with one delay cell and by two NOR gates is presented. The proposed circuits have been simulated in spice with 0.35 μm (micrometer technology at supply voltage of 3.3V. The first design shows 35-40% reduction in power consumption and second design shows 37.5-41.8% power saving as compared to conventional DCO. The frequency range of first and second design varies [3.1316 - 3.1085] GHz and [3.8112 – 3.7867] GHz respectively with the variation in control word from ‘000000’ to ‘000001'. Power consumption of first and second design varies [640.3845 - 700.2977] μW and [617.6616 -6 77.3996] μW respectively.

  17. 基于无差拍控制的有源电力滤波器直接电流控制研究%Research on Direct Current Control of Active Power Filter Based on Deadbeat Control

    Institute of Scientific and Technical Information of China (English)

    贺永平; 庄圣贤

    2015-01-01

    An improved method for direct current control of active power filter based on deadbeat control is proposed. Compared with the traditional current control method, the deadbeat control is carried out in the αβ coordinate system to avoid the serious coupling by dq transform. Fundamental component of load current is brought into the given value of source current, the system dynamic response is enhanced. The load current and the source voltage are feed-forward compensated to improve the compensation precision of the system. The simulation results show that the improved method has better dynamic performance than the conventional control method and also it can realize the selective compensation of load current between harmonics and reactive component.%提出一种基于无差拍控制的有源电力滤波器网侧电流直接控制方法。与传统网侧电流控制法相比,该方法的无差拍电流控制策略在αβ坐标系中实现,抑制了由dq变换引入的严重耦合;引入负载电流基波分量作为网侧电流的给定值,增强了系统的动态响应;对负载电流和电网电压进行前馈补偿,进一步提高了系统的补偿精度。仿真结果表明:改进方法比传统控制法具有更优越的动态性能,且可以实现APF对负载电流谐波分量和无功分量的选择性补偿。

  18. 14 CFR 27.695 - Power boost and power-operated control system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or...

  19. 14 CFR 29.695 - Power boost and power-operated control system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or...

  20. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the solar irradiance and temperature measurements that have been used in conventional power reserve control schemes to estimate the available PV power are not required, and thereby being a sensorless approach with reduced cost. Experimental tests have been...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  1. 主动配电网背景下无功电压控制方法研究综述%Research Overview on Reactive Power Voltage Control Method Under Background of Active Distribution Network

    Institute of Scientific and Technical Information of China (English)

    倪鹏; 孙富荣

    2016-01-01

    介绍了主动配电网(ADN)背景下分布式电源(DG)接入对配电网电压分布和电压稳定性影响,从电网结构优化调压措施、电网设备的调压措施、电力系统无功优化调度调压措施等方面阐述了ADN无功电压控制方法。基于当前研究现状,总结了现有关于ADN无功电压控制研究存在的不足,并指出了在未来亟待解决的几个问题。%Introduction was made to the impacts of distributed generation (DG) access under background of active distribution network (ADN) on the voltage distribution of DG and voltage stability. This paper expounded on the ADN reactive power voltage control method from the aspects of pressure regulating measures of power network structure optimization, power network equipment, optimal reactive power dispatch of power system and so on. Based on the current research status, this paper summarized the shortcomings existing in the research on ADN reactive power voltage control and pointed out several problems which are much-needed to solve in the future.

  2. A Wind Power and Load Prediction Based Frequency Control Approach for Wind-Diesel-Battery Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Chao Peng

    2015-01-01

    Full Text Available A frequency control approach based on wind power and load power prediction information is proposed for wind-diesel-battery hybrid power system (WDBHPS. To maintain the frequency stability by wind power and diesel generation as much as possible, a fuzzy control theory based wind and diesel power control module is designed according to wind power and load prediction information. To compensate frequency fluctuation in real time and enhance system disturbance rejection ability, a battery energy storage system real-time control module is designed based on ADRC (active disturbance rejection control. The simulation experiment results demonstrate that the proposed approach has a better disturbance rejection ability and frequency control performance compared with the traditional droop control approach.

  3. Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  4. Abdicating power for control: a precision timing strategy to modulate function of flight power muscles

    Science.gov (United States)

    Sponberg, S.; Daniel, T. L.

    2012-01-01

    Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power–phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left–right pairs of flight muscles normally fire precisely, within 0.5–0.6 ms of each other; (ii) during a yawing optomotor response, left—right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left–right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left—right timing differences. Because many organisms also have muscles operating with high power–phase gains (Δpower/Δphase), this motor control strategy may be ubiquitous in locomotor systems. PMID:22833272

  5. Control for Wind Power Generation Based on Inverse System Theory

    Directory of Open Access Journals (Sweden)

    Jiyong Zhang

    2013-11-01

    Full Text Available Traditional Double-fed Wind Generation systems are based on the vector control method, and it is dependent on motor parameters. The performance of the control system will be affected with the parameters changing,. This paper proposes a new control method based on inverse system and variable structure sliding mode(VSS theories, through the inverse system theory, the structure of its state’s equation, obtaining the structure of the inverse system, the establishment of Wind Power Generation closed-loop control system is established. The VSS controller, designed with exponential reaching law, can improve the dynamic performance in normal operation range effectively. When the system operates with variable speed constant frequency (VSCF and the phase voltage drops, the simulations show that the control system can control the DC link voltage steabily, maintain unity power factor, achieve the decoupling of the active and reactive power. And experiments show that the control method used in  VSCF wind power system is feasible.  

  6. Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

    Science.gov (United States)

    Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

    2008-12-01

    Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

  7. Power control for hot gas engines

    Science.gov (United States)

    Macglashan, W. F. (Inventor)

    1980-01-01

    A hot gas engine in which the expander piston of the engine is connected to an expander crankshaft. A displacer piston of the engine is connected to a separate displacer crankshaft which may or may not be coaxial with the expander crankshaft. A phase angle control mechanism used as a power control for changing the phase angle between the expander and displacer crankshaft is located between the two crankshafts. The phase angle control mechanism comprises a differential type mechanism comprised of a pair of gears, as for example, bevel gears, one of which is connected to one end of the expander crankshaft and the other of which is connected to the opposite end of the displacer crankshaft. A mating bevel gear is disposed in meshing engagement with the first two level gears to provide a phase angle control between the two crankshafts. Other forms of differential mechanisms may be used including conventional spur gears connected in a differential type arrangement.

  8. Active control of radiated sound using nearfield pressure sensing

    Institute of Scientific and Technical Information of China (English)

    CHEN Ke'an; YIN Xuefei

    2004-01-01

    Based on nearfield sound pressure sensing to pick up error information, an approach for constructing active acoustic structure to effectively reduce radiated sound power at low frequency is proposed. The idea is that a nearfield pressure after active control is used as error signals and transformed into an objective function in adaptive active control process.Firstly sound power expression using near-field pressure radiated from a flexible structure is derived, and then three kind of nearfield pressure based active control strategies, I.e. Minimization of radiated sound power, minimization of sound power for dominant radiation modes and minimization of sound power for modified dominant radiation modes are respectively presented and applied to active control of radiated single and broadband noise. Finally computer simulations on sound power reduction under three strategies are conducted and it is shown that the proposed active control strategies are invalid and considerable reduction in radiated sound power can be achieved.

  9. Autonomous Control of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Basher, H.

    2003-10-20

    A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in emergency situations, fault detection and diagnosis, nuclear reactor alarm processing and diagnosis, and reactor load-following operations, to name a few. With the advancement of new technologies and computing power, it is feasible to automate most of the nuclear reactor control and operation, which will result in increased safety and economical benefits. This study surveys current status, practices, and recent advances made towards developing autonomous control systems for nuclear reactors.

  10. Power Electronics Control of Wind Energy in Distributed Power System

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  11. Power flow controller with a fractionally rated back-to-back converter

    Science.gov (United States)

    Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish

    2016-03-08

    A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

  12. Power factor control system for ac induction motors

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1981-01-01

    A power control circuit for an induction motor is disclosed in which a servo loop is used to control power input by controlling the power factor of motor operation. The power factor is measured by summing the voltage and current derived square wave signals.

  13. Trend of Control Technique of Power Electronic Equipments for Power System

    Science.gov (United States)

    Kimura, Noriyuki; Nakajima, Tatsuhito; Gibo, Naoki

    This paper aims to introduce recent topics about the control technique of power electronic equipments for power system. the control technique is explained from the view points of the power system control, the local system control and the converter control. The installation of STATCOM in Japan and UPFC in Korea are mentioned as the examples.

  14. Distributed solid state programmable thermostat/power controller

    Science.gov (United States)

    Alexander, Jane C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2008-01-01

    A self-contained power controller having a power driver switch, programmable controller, communication port, and environmental parameter measuring device coupled to a controllable device. The self-contained power controller needs only a single voltage source to power discrete devices, analog devices, and the controlled device. The programmable controller has a run mode which, when selected, upon the occurrence of a trigger event changes the state of a power driver switch and wherein the power driver switch is maintained by the programmable controller at the same state until the occurrence of a second event.

  15. Integrating Autonomous Load Controllers in Power Systems

    DEFF Research Database (Denmark)

    Douglass, Philip James

    violations of voltage constraints. This voltage-sensitive controller can also operate alone, without the frequency-sensitive controller, to provide voltage regulation service and increase load diversity in any distribution network where lower voltage level corresponds to higher load.The frequency......-sensitive and voltage-sensitive autonomous load are viable alternatives to conventional frequency and voltage control devices. When used in combination, they complement each other. In systems where the operator has centrally dispatchable resources to regulate frequency, these resources can be used to dispatch otherwise...... autonomous frequency-sensitive loads. Moreover, where centrally dispatchable frequency regulation resources can rapidly change operating points, such as in a micro-grid, the energy sources can be used as transmitters for a ultra-low-bandwidth uni-directional power line communication system....

  16. Power Control of Permanent Magnet Generator Based Variable Speed Wind Turbines

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2009-01-01

    When the wind power accounts for a large portion of the grid, it will be required to regulate the active power and reactive power. This paper investigates a MWlevel variable speed wind turbine with a permanent magnet synchronous generator (PMSG). The power control capabilities of two kinds...

  17. 基于混合储能的并网光伏电站有功分级控制策略%Active Power Hierarchical Control Strategy of Interconnected Photovoltaic Station Based on Hybrid Energy Storage

    Institute of Scientific and Technical Information of China (English)

    鲍雪娜; 张建成; 徐明; 刘汉民

    2013-01-01

    针对自然条件下光伏电源有功出力的波动性,以超级电容器和磷酸铁锂电池组成的混合储能系统为基础,制定了有功分级控制策略.首先分析了光伏电站整体结构及混合储能装置的接入方式,然后考虑电网需求利用指数平滑法来实时更新光伏电站整体出力参考值,实现第1级控制.根据储能元件能量存储与功率吞吐特性,提出了以超级电容器为充放电主体的混合储能系统能量管理策略,实现第2级控制,并设计了脉宽调制的控制原理电路.编程计算结果证实了所述方法的有效性.%In view of the active power fluctuation of large capacity photovoltaic (PV) power systems, based on a hybrid energy storage system consisting of supercapacitors and lithium-ion ferrous phosphate batteries, an active power hierarchical control strategy is formulated to optimize the output power of PV source. First, the overall structure of photovoltaic power station and the way of accessing the hybrid energy storage system are analyzed. Then, by considering the power grid needs, the exponential smoothing method is used to real-time update the reference values of output power to realize the first level control. The energy management strategy is put forward according to the storage characteristics of energy storage components and power throughput so as to realize the second level control of the hybrid energy storage system. In addition, an energy management strategy is put forward with supercapacitors as the principal part of charge and discharge. Finally, a control circuit of pulse width modulation (PWM) is designed. Programming results demonstrate the effectiveness of the proposed method.

  18. Power electronics and control for wind power systems

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede

    2009-01-01

    the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most emerging...... renewable energy sources, wind energy, which by means of power electronics are changing from being minor energy sources to be acting as important power sources in the electrical network.......The global electrical energy consumption is still rising and there is a steady demand to increase the power capacity. It is expected that it has to be doubled within 20 years. The production, distribution and use of the energy should be as technological efficient as possible and incentives to save...

  19. Fuzzy Logic Based Control of Power of PEM Fuel Cell System for Residential Application

    Directory of Open Access Journals (Sweden)

    Khaled MAMMAR

    2009-07-01

    Full Text Available This paper presents a dynamic model of Fuel cell system for residential power generation. The models proposed include a fuel cell stack model, reformer model and DC/AC inverter model. Furthermore a fuzzy logic (FLC controller is used to control active power of PEM fuel cell system. The controller modifies the hydrogen flow feedback from the terminal load. Simulation results confirmed the high performance capability of the fuzzy logic controller to control power generation.

  20. Fuzzy Logic Based Control of Power of PEM Fuel Cell System for Residential Application

    OpenAIRE

    Khaled MAMMAR; CHAKER, Abdelkader

    2009-01-01

    This paper presents a dynamic model of Fuel cell system for residential power generation. The models proposed include a fuel cell stack model, reformer model and DC/AC inverter model. Furthermore a fuzzy logic (FLC) controller is used to control active power of PEM fuel cell system. The controller modifies the hydrogen flow feedback from the terminal load. Simulation results confirmed the high performance capability of the fuzzy logic controller to control power generation.

  1. FPGA for Power Control of MSL Avionics

    Science.gov (United States)

    Wang, Duo; Burke, Gary R.

    2011-01-01

    A PLGT FPGA (Field Programmable Gate Array) is included in the LCC (Load Control Card), GID (Guidance Interface & Drivers), TMC (Telemetry Multiplexer Card), and PFC (Pyro Firing Card) boards of the Mars Science Laboratory (MSL) spacecraft. (PLGT stands for PFC, LCC, GID, and TMC.) It provides the interface between the backside bus and the power drivers on these boards. The LCC drives power switches to switch power loads, and also relays. The GID drives the thrusters and latch valves, as well as having the star-tracker and Sun-sensor interface. The PFC drives pyros, and the TMC receives digital and analog telemetry. The FPGA is implemented both in Xilinx (Spartan 3- 400) and in Actel (RTSX72SU, ASX72S). The Xilinx Spartan 3 part is used for the breadboard, the Actel ASX part is used for the EM (Engineer Module), and the pin-compatible, radiation-hardened RTSX part is used for final EM and flight. The MSL spacecraft uses a FC (Flight Computer) to control power loads, relays, thrusters, latch valves, Sun-sensor, and star-tracker, and to read telemetry such as temperature. Commands are sent over a 1553 bus to the MREU (Multi-Mission System Architecture Platform Remote Engineering Unit). The MREU resends over a remote serial command bus c-bus to the LCC, GID TMC, and PFC. The MREU also sends out telemetry addresses via a remote serial telemetry address bus to the LCC, GID, TMC, and PFC, and the status is returned over the remote serial telemetry data bus.

  2. Unified power flow controller: Modeling, stability analysis, control strategy and control system design

    Science.gov (United States)

    Sreenivasachar, Kannan

    2001-07-01

    Unified power flow controller (UPFC) has been the most versatile Flexible AC Transmission System (FACTS) device due to its ability to control real and reactive power flow on transmission lines while controlling the voltage of the bus to which it is connected. UPFC being a multi-variable power system controller it is necessary to analyze its effect on power system operation. To study the performance of the UPFC in damping power oscillations using PSCAD-EMTDC software, a de-coupled control system has been designed for the shunt inverter to control the UPFC bus voltage and the DC link capacitor voltage. The series inverter of a UPFC controls the real power flow in the transmission line. One problem associated with using a high gain PI controller (used to achieve fast control of transmission line real power flow) for the series inverter of a UPFC to control the real power flow in a transmission line is the presence of low damping. This problem is solved in this research by using a fuzzy controller. A method to model a fuzzy controller in PSCAD-EMTDC software has also been described. Further, in order to facilitate proper operation between the series and the shunt inverter control system, a new real power coordination controller has been developed and its performance was evaluated. The other problem concerning the operation of a UPFC is with respect to transmission line reactive power flow control. Step changes to transmission line reactive power references have significant impact on the UPFC bus voltage. To reduce the adverse effect of step changes in transmission line reactive power references on the UPFC bus voltage, a new reactive power coordination controller has been designed. Transient response studies have been conducted using PSCAD-EMTDC software to show the improvement in power oscillation damping with UPFC. These simulations include the real and reactive power coordination controllers. Finally, a new control strategy has been proposed for UPFC. In this

  3. Comparison of Power Control Strategies for DFIG Wind Turbines

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Luna, A.; Rodríguez, P.

    2008-01-01

    The classical control techniques for regulating the active and reactive power delivery in doubly fed induction generators (DFIG), for wind power applications, are normally based on voltage oriented control (VOC) strategies. Among these algorithms, those that work in a synchronous reference frame...... VOC strategy able to control the operation of a DFIG in the αβ reference frame, with no need of flux position estimation, something that conducts to a more simple and robust algorithm. In order to evaluate the advantages of this new control proposal, namely VOC-RRF, their performance will be compared......, attached to the magnetic flux vector, became very popular. In spite of the good behaviour of such algorithms their performance depends highly on an accurate detection of the stator flux position, something that can be critical under unbalanced or distorted grid voltage conditions. This paper presents a new...

  4. Smart actuators for active vibration control

    Science.gov (United States)

    Pourboghrat, Farzad; Daneshdoost, Morteza

    1998-07-01

    In this paper, the design and implementation of smart actuators for active vibration control of mechanical systems are considered. A smart actuator is composed of one or several layers of piezo-electric materials which work both as sensors and actuators. Such a system also includes micro- electronic or power electronic amplifiers, depending on the power requirements and applications, as well as digital signal processing systems for digital control implementation. In addition, PWM type micro/power amplifiers are used for control implementation. Such amplifiers utilize electronic switching components that allow for miniaturization, thermal efficiency, cost reduction, and precision controls that are robust to disturbances and modeling errors. An adaptive control strategy is then developed for vibration damping and motion control of cantilever beams using the proposed smart self-sensing actuators.

  5. Active micromachines: Microfluidics powered by mesoscale turbulence

    CERN Document Server

    Thampi, Sumesh P; Shendruk, Tyler N; Golestanian, Ramin; Yeomans, Julia M

    2016-01-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterised by mesoscale turbulence, the emergence of chaotic flow structures. By immersing an ordered array of symmetric rotors in an active fluid, we introduce a microfluidic system that exploits spontaneous symmetry breaking in mesoscale turbulence to generate work. The lattice of rotors self-organises into a spin-state where neighbouring discs continuously rotate in permanent alternating directions due to combined hydrodynamic and elastic effects. Our virtual prototype demonstrates a new research direction for the design of micromachines powered by the nematohydrodynamic properties of active turbulence.

  6. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power

  7. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power efficien

  8. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power efficien

  9. MODELLING AND FUZZY LOGIC CONTROL OF PEM FUEL CELL SYSTEM POWER GENERATION FOR RESIDENTIAL APPLICATION

    OpenAIRE

    Khaled MAMMAR; CHAKER, Abdelkader

    2010-01-01

    This paper presents a dynamic model of Fuel cell system for residential power generation. The models proposedinclude a fuel cell stack model, reformer model and DC/AC inverter model. More then an analytical details ofhow active and reactive power output of a proton-exchange-membrane (PEM) fuel cell system is controlled.Furthermore a fuzzy logic (FLC) controller is used to control active power of PEM fuel cell system. Thecontroller modifies the hydrogen flow feedback from the terminal load. Si...

  10. DESIGN CONSIDERATIONS FOR SERIES HYBRID ACTIVE POWER FILTER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some important factors for designing a series hybrid active power filter (SHAPF) are presented in this paper for the case when the load is varied in a wide range and/or the source voltage is seriously distorted. Special design of passive filters, adaptive control of parameter and multi variant control are discussed in detail. The filter is stable, has good performance, and causes small capacitive reactive current. The simulation and experimental results accorded with the theoretical analysis results.

  11. The Investigation of Properties of Copper Vapor Pulsed Power Active Medium in Time and Development of Operational Control Methods of Output Radiation Parameters on Their Basis

    Directory of Open Access Journals (Sweden)

    N. A. Lyabin

    2014-01-01

    Full Text Available The given paper focuses on the investigation in time of the properties of a pulsed CVL AM using CVLS of the type DO – SFC –PA and mistiming method in wide limits (± 1000 ns of a DO light radiation pulse relatively to PA light pulse from the moment of maximal amplification.It was stated that CVL AM in relation to its own radiation has got four characteristic time zones following each other and repeating from pulse to pulse: weak absorption 30-50 ns in length (appears at the initial stage of pulse pump current development, amplification 20-40 ns in length (appears at the sharp leading edge of the current pulse, complete absorption over 1000 ns in length (appears at the pulse current cut and follows the pulse and maximal transparency over 1000 ns in length (before the new current pulse.These AM properties have become the basis for developing methods and electron devices of operational control of power and radiation pulse repetition frequency (PRF, including packet and pulse-to-pulse modulation according to preset algorithm in industrial CVLs and CVLSs of new generation. Based on such class of CVLs and CVLSs a set of up-to-date automated laser technological installations (ALTI “Karavella” with computerized control: “Karavella-1”, “Karavella-1M”, “Karavella-2”, “Karavella-2M” were created for precision microprocessing of materials for electron engineering products (EEP 0.02 – 2 mm thick.The capability of ALTI “Karavella” to operate in the modes of high speed control over the laser radiation parameters allows to increase significantly the operational control over technological processes of manufacturing precision parts, to increase the productivity of material microprocessing, to make cuts and holes with minimal roughness and zone of thermal influence.The main conclusions made in the given paper on the results of experimental investigations of CVL AM time properties are also true for lasers on self-contained transitions

  12. A Turbine-powered UAV Controls Testbed

    Science.gov (United States)

    Motter, Mark A.; High, James W.; Guerreiro, Nelson M.; Chambers, Ryan S.; Howard, Keith D.

    2007-01-01

    The latest version of the NASA Flying Controls Testbed (FLiC) integrates commercial-off-the-shelf components including airframe, autopilot, and a small turbine engine to provide a low cost experimental flight controls testbed capable of sustained speeds up to 200 mph. The series of flight tests leading up to the demonstrated performance of the vehicle in sustained, autopiloted 200 mph flight at NASA Wallops Flight Facility's UAV runway in August 2006 will be described. Earlier versions of the FLiC were based on a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate at Fort Eustis, Virginia and NASA Langley Research Center. The newer turbine powered platform (J-FLiC) builds on the successes using the relatively smaller, slower and less expensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches with the implementation of C-coded experimental controllers. Tracking video was taken during the test flights at Wallops and will be available for presentation at the conference. Analysis of flight data from both remotely piloted and autopiloted flights will be presented. Candidate experimental controllers for implementation will be discussed. It is anticipated that flight testing will resume in Spring 2007 and those results will be included, if possible.

  13. Electronically controlled heat sink for high-power laser diodes

    Science.gov (United States)

    Vetrovec, John

    2009-05-01

    We report on a novel electronically controlled active heat sink for high-power laser diodes offering unparalleled capacity in high-heat flux handling and temperature control. The heat sink receives diode waste heat at high flux and transfers it at reduced flux to environment, coolant fluid, heat pipe, or structure. Thermal conductance of the heat sink is electronically adjustable, allowing for precise control of diode temperature and the diode light wavelength. When pumping solid-state or alkaline vapor lasers, diode wavelength can be precisely temperature-tuned to the gain medium absorption features. This paper presents the heat sink physics, engineering design, and performance modeling.

  14. Harmonics Mitigation Using Active Power Filter

    Directory of Open Access Journals (Sweden)

    Sourabh Gupta

    2013-06-01

    Full Text Available This paper is proposed to reconsider the development of active power filter (APF technologies that are routinely utilized to mitigate harmonics in utility power lines. This reconsider can furthermore be considered as a “tutorial-type paper” as it provides a holistic coverage of the APF technologies by omitting the tedious details, but without losing the major essence of the subject matter. It is wanted that by this approach, it would be likely to lure more power engineering readers to be involved in this important and growing area. The discussion starts with a short overview of harmonic distortion difficulties and their impacts on electric power and powered value. The operation of common APF topologies, namely the shunt, sequence and hybrid APFs are recounted in minutia. This is followed by a reconsider on different types of reference pointer estimation extraction methods. In specific, the application of the p-q and elongation p-q theorems to extract the quotation pointers are elaborated, as they are the most commonly discovered in practical APF systems eventually, an overview of the APF command schemes is provided. A short consideration on the APF-solar photovoltaic scheme is furthermore granted. At the end of the paper, important references are cited to aid readers who are interested to discover the subject in larger detail.

  15. Active Flow Control

    Science.gov (United States)

    FFOWCS WILLIAMS, J. E.

    2001-01-01

    This paper considers the two-dimensional problem of a plane vortex sheet disturbed by an impulsive line source. A previous incorrect treatment of this problem is examined in detail. Instabilities of the vortex sheet are triggered by the source and grow exponentially in space and time. The Green function is constructed for the problem and it is shown that a point source properly positioned and delayed will induce a field that cancels the unstable growing modes. The resulting displacement of the vortex sheet is expressed in simple terms. The instabilities are checked by the anti-source which combines with the field of the primary source into a vortex sheet response which decays with time at large time. This paper is a contribution to the study of active control of shear layer instabilities, the main contribution being to clear up a previous paper with peculiar results that are, in fact, wrong.

  16. Digitally Controlled High Availability Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    MacNair, David; /SLAC

    2009-05-07

    This paper will report on the test results of a prototype 1320 watt power module for a high availability power supply. The module will allow parallel operation for N+1 redundancy with hot swap capability. The two quadrant output of each module allows pairs of modules to provide a 4 quadrant (bipolar) operation. Each module employs a novel 4 FET buck regulator arranged in a bridge configuration. Each side of the bridge alternately conducts through a small saturable ferrite that limits the reverse current in the FET body diode during turn off. This allows hard switching of the FETs with low switching losses. The module is designed with over-rated components to provide high reliability and better then 97% efficiency at full load. The modules use a Microchip DSP for control, monitoring, and fault detection. The switching FETS are driven by PWM modules in the DSP at 60 KHz. A Dual CAN bus interface provides for low cost redundant control paths. The DSP will also provide current sharing between modules, synchronized switching, and soft start up for hot swapping. The input and output of each module have low resistance FETs to allow hot swapping and isolation of faulted units.

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

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

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

  18. Delta Power Control Strategy for Multi-String Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    With a still increasing penetration level of grid-connected PV systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required....... Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the proposed delta power control strategy, where the power reserve according to the delta power constraint is achieved under several operating conditions....

  19. Delta Power Control Strategy for Multi-String Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    With a still increasing penetration level of grid-connected PV systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required...... for the entire PV system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the delta power control strategy, where the power reserve according to the delta power constraint is achieved under several...

  20. Monitoring Biological Activity at Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  1. Retrofitting automated process control systems at Ukrainian power stations

    Energy Technology Data Exchange (ETDEWEB)

    B.E. Simkin; V.S. Naumchik; B.D. Kozitskii (and others) [OAO L' vovORGRES, Lviv (Ukraine)

    2008-04-15

    Approaches and principles for retrofitting automated process control systems at Ukrainian power stations are considered. The results obtained from retrofitting the monitoring and control system of Unit 9 at the Burshtyn thermal power station are described.

  2. A hybrid electromechanical solid state switch for ac power control

    Science.gov (United States)

    1972-01-01

    Bidirectional thyristor coupled to a series of actuator driven electromechanical contacts generates hybrid electromechanical solid state switch for ac power control. Device is useful in power control applications where zero crossover switching is required.

  3. New hybrid active power filter for harmonic current suppression and reactive power compensation

    Science.gov (United States)

    Biricik, Samet; Cemal Ozerdem, Ozgur; Redif, Soydan; Sezai Dincer, Mustafa

    2016-08-01

    In the case of undistorted and balanced grid voltages, low ratio shunt active power filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt APF. A new method for alleviating the negative effects of a nonideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field-programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance result of the proposed HAPF system is tested and presented under nonideal supply voltage conditions.

  4. 基于自抗扰控制器的直驱式永磁同步风电系统双PWM控制%Direct-drive permanent magnet synchronous wind power generation system based on active disturbance rejection controller

    Institute of Scientific and Technical Information of China (English)

    伍亮; 杨金明; 贾盼盼

    2013-01-01

    Based on the mathematical model of direct-drive permanent magnet synchronous wind power generation system,the active disturbance rejection controllers (ADRC) are designed for the generator-side converter and the grid-side converter respectively.Using the ADRC,the wind power generation system with dual PWM converter can track maximum power point by the generator-side converter and maintain a constant voltage of DC capacitor by the grid-side converter under rated wind speed.The simulation result shows that comparing with the traditional PI controller,wind power generation system with ADRC can track the reference turbine speed quickly without overshoot.At the same time,voltage disturbance on DC capacitor caused by the variation of wind speed and grid voltage disturbance is effectively restrained.So the wind power generation system with ADRC has outstanding control performance.%针对直驱式永磁同步风力发电机组,分别设计了电机侧和电网侧的变换器自抗扰控制器,从而实现在额定风速以下对电机侧的最大风能跟踪控制、电网侧直流电容电压恒定控制.与常规PI控制器相比,采用自抗扰控制器的直驱动式永磁同步发电系统,能够实现对指令转速快速及无超调跟踪、有效抑制风速变化及电网电压扰动对电容电压的影响,具有较为优秀的控制性能.

  5. Assessment of PCDD/F and PBDD/F emissions from coal-fired power plants during injection of brominated activated carbon for mercury control

    Energy Technology Data Exchange (ETDEWEB)

    Hutson, N.D.; Ryan, S.P.; Touati, A. [US EPA, Research Triangle Park, NC (United States)

    2009-08-15

    The effect of the injection of brominated powdered activated carbon (Br-PAC) on the emission of brominated and chlorinated dioxins and furans in coal combustion flue gas has been evaluated. The sampling campaigns were performed at two U.S. Department of Energy (DOE) demonstration sites where brominated PAC was being injected for control of mercury emissions. The results of the sampling campaigns showed that injection of the brominated PAC upstream of the electrostatic precipitator (ESP) did not increase the emissions of total and Toxic Equivalent (TEQ) chlorinated and brominated dioxin compounds. Rather, the data suggested the sorbent may capture these compounds and reduce their concentration in the flue gas stream. This effect, when seen, was small, and independent of the type of plant emission controls, temperature at the point of injection, or fuel-chlorine content. The addition of the brominated PAC sorbent resulted in slight increases the total content of chlorinated dioxins and furan in the particulate matter (ash) collected in the ESP, but did not increase its overall toxicity.

  6. 21 CFR 890.3725 - Powered environmental control system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered environmental control system. 890.3725... environmental control system. (a) Identification. A powered environmental control system is an AC- or battery-powered device intended for medical purposes that is used by a patient to operate an environmental...

  7. Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

    DEFF Research Database (Denmark)

    Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

    2008-01-01

    This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...

  8. 14 CFR 23.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 23.1142... Powerplant Controls and Accessories § 23.1142 Auxiliary power unit controls. Means must be provided on the... power unit....

  9. Spectrum management considerations of adaptive power control in satellite networks

    Science.gov (United States)

    Sawitz, P.; Sullivan, T.

    1983-01-01

    Adaptive power control concepts for the compensation of rain attenuation are considered for uplinks and downlinks. The performance of example power-controlled and fixed-EIRP uplinks is compared in terms of C/Ns and C/Is. Provisional conclusions are drawn with regard to the efficacy of uplink and downlink power control orbit/spectrum utilization efficiency.

  10. 7 CFR 917.33 - Powers of Control Committee.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Powers of Control Committee. 917.33 Section 917.33... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.33 Powers of Control Committee. The Control Committee shall have the following powers: (a) To administer, as specifically provided in this part,...

  11. Motor power control circuit for ac induction motors

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1983-01-01

    A motor power control of the type which functions by controlling the power factor wherein one of the parameters of power factor current on time is determined by the on time of a triac through which current is supplied to the motor. By means of a positive feedback circuit, a wider range of control is effected.

  12. POWER QUALITY CONTROL IN A WIND POWER GENERATING SYSTEM USING SVPWM CONTROLLED UNIFIED POWER QUALITY CONDITIONER WITH GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    P.SARAVANAN

    2013-06-01

    Full Text Available Renewable energy resources (RES are being increasingly connected in distribution systems utilizing power electronic converters.This paper proposes a novel control design for achieving maximum benefits from the grid-interfacing inverters when installed in 3-phase 3-wire distribution systems. The main aim of the proposed system is to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. Modulation technique used is Space Vector Pulse Width Modulation (SVPWM. Simulation and experimental studies on a three phase 3 wire distribution system is used to verify the performance and real time implementation of the control design.

  13. Application of power amplifier OPA544 in active magnetic bearing control system%功率放大器OPA544在主动磁悬浮控制系统中的应用

    Institute of Scientific and Technical Information of China (English)

    钱婧; 汪希平; 田丰; 郭丽; 杨玉敏

    2011-01-01

    在磁悬浮系统的功放中采用OPA544功率器件实现对系统输出负载电流的放大作用,其性能将随功放的类型而变化.针对毫米级气隙的悬浮系统,设计前级PID控制调理电路,与OPA544功率放大器配合实现差动式电流控制,最终在一台主动磁悬浮平板试验台上实现系统的稳定悬浮,仿真结果与试验情况基本吻合.%Adopt power amplifier OPA544 to amplifier the output load current to achieve the system's current increasing. The controlling model was designed and PID controlling strategy was selected, therefore system's simulation was achieved on a basis of the whole module's parameters. The order of magnitude for the air gap or the displacement was millimeter. As to suspension under control, design PID controlling circuit to attain the full current. The use of two electronic component of OPA544 could realized push-pull power amplifier control thoughts, and then achieved the establishment of active magnetic plate's dynamic equilibrium,and better system stability was gained. Actual experiments and facts dovetailed nicely with simulation as for the comparison with the virtual results.

  14. Centralised power control of wind farm, with doubly fed induction generators

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Sørensen, Poul; Iov, Florin;

    2006-01-01

    At the moment, the control ability of wind farms is a prime research concern for the grid integration of large wind farms, due to their required active role in the power system. This paper describes the on-going work of a research project, whose overall objective is to analyse and assess...... to regulate the wind farm power production to the reference power ordered by the system operators. The presented wind farm control has a hierarchical structure with both a central control level and a local control level. The central wind farm control level controls the power production of the whole farm...... by sending out reference power signals to each individual wind turbine, while the local wind turbine control level ensures that the reference power signal send by the central control level is reached. The performance of the control strategy is assessed and discussed by means of simulations illustrated both...

  15. Centralised power control of wind farm with doubly fed induction generators

    DEFF Research Database (Denmark)

    Hansen, A.D.; Sørensen, Poul Ejnar; Iov, F.;

    2006-01-01

    At the moment, the control ability of wind farms is a prime research concern for the grid integration of large wind farms, due to their required active role in the power system. This paper describes the on-going work of a research project, whose overall objective is to analyse and assess...... to regulate the wind farm power production to the reference power ordered by the system operators. The presented wind farm control has a hierarchical structure with both a central control level and a local control level. The central wind farm control level controls the power production of the whole farm...... by sending out reference power signals to each individual wind turbine, while the local wind turbine control level ensures that the reference power signal send by the central control level is reached. The performance of the control strategy is assessed and discussed by means of simulations illustrated both...

  16. Coordinated Fast Primary Frequency Control from Offshore Wind Power Plants in MTDC System

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio

    2016-01-01

    In this paper, coordinated fast primary frequency control (FPFC) from offshore wind power plants (OWPPs) integrated to surrounding onshore AC power system through a three terminal VSC HVDC system is presented. The onshore AC grid frequency variations are emulated at offshore AC grid through...... and the dynamics of wind turbine are also discussed. The corresponding impact of OWPPs active power output variation at different wind speeds on the power system frequency control and DC grid voltage is also presented. The results show that the proposed coordinated fast primary frequency control from OWPPs...... improves the power system frequency while relieving the stress on the other AC grid participating in frequency control....

  17. Computing an operating parameter of a unified power flow controller

    Science.gov (United States)

    Wilson, David G; Robinett, III, Rush D

    2015-01-06

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  18. Alternatives for Primary Frequency Control Contribution from Wind Power Plants Connected to VSC-HVDC Intertie

    DEFF Research Database (Denmark)

    Laukhamar, Andreas Grøsvik; Zeni, Lorenzo; Sørensen, Poul Ejnar

    how a large offshore wind power plant (OWPP) with high voltage direct current (HVDC) intertie connection to two asynchronous onshore AC power systems can be part of the solution in providing short-term mutual active power balancing. The primary frequency control is investigated for four different...... in a sharing of the primary reserves and rolling inertia between the two onshore AC power systems connected to the HVDC intertie, whilst also exploiting the OWPP in the primary frequency control scheme....

  19. Power spectra of active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    WANG TaiShan; WU YuXiang; LIU Yuan

    2009-01-01

    The power spectral densities (PSDs) for a sample of active galactic nuclei (AGNs) are analyzed in both the frequency domain and the time domain. We find for each object that for broadband noise a character timescale-bifurcation timescale of Fourier and time-domain PSD exists in the 103-106 s range,below which the time-domain power spectrum is systematically higher than the corresponding Fourier spectrum. The relationship between bifurcation timescale, AGN mass and luminosity is studied. Compared with the fact that similar phenomena have been found for Galactic black hole candidates (GBHs)with bifurcation timescale ~0.1 s but not for accreting neutron stars, our finding indicates that AGNs and GBHs have common intrinsic nature in rapid X-ray variability with a character time parameter scaled with their masses.

  20. Power spectra of active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The power spectral densities(PSDs)for a sample of active galactic nuclei(AGNs)are analyzed in both the frequency domain and the time domain.We find for each object that for broadband noise a character timescale-bifurcation timescale of Fourier and time-domain PSD exists in the 10 3 -10 6 s range, below which the time-domain power spectrum is systematically higher than the corresponding Fourier spectrum.The relationship between bifurcation timescale,AGN mass and luminosity is studied.Compared with the fact that similar phenomena have been found for Galactic black hole candidates(GBHs) with bifurcation timescale~0.1 s but not for accreting neutron stars,our finding indicates that AGNs and GBHs have common intrinsic nature in rapid X-ray variability with a character time parameter scaled with their masses.

  1. Reinforcement learning based backstepping control of power system oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, Ali; Eftekharnejad, Sara; Feliachi, Ali [Advanced Power and Electric Research Center (APERC), West Virginia University, Morgantown, WV 26506-6109 (United States)

    2009-11-15

    This paper proposes a reinforcement learning based backstepping control technique for damping oscillations in electric power systems using the generators excitation systems. Decentralized controllers are first designed using the backstepping technique. Then, reinforcement learning is used to tune the gains of these controllers to adapt to various operating conditions. Simulation results for a two area power system show that the proposed control technique provides better damping than (i) conventional power system stabilizers and (ii) backstepping fixed gain controllers. (author)

  2. Analysis and Realization of a Fast Repetitive Controller in Active Power Filter System%一种快速重复控制策略在APF中的实现和分析

    Institute of Scientific and Technical Information of China (English)

    宫金武; 查晓明; 陈佰锋

    2011-01-01

    The repetitive control and resonant control are widely used in grid-connected voltage-source converters recently,such as uninterruptible power supplies(UPS),photovoltaic inverter(PV) and active power filter(APF).This paper introduces a new repetitive control strategy in APF system,whose repetitive period is only one half of the traditional and could eliminate all odd harmonics as a bank of resonant controllers.Compared to traditional repetitive control,proposed control strategy has faster tracking speed and smaller steady-state error.Compared to traditional PR control,it could be simply implemented in digital processor.Theory analysis with simulations and experiments demonstrate the validity and superiority of proposed fast repetitive control strategy.%重复控制和谐振控制在并网电压源型逆变器中应用广泛,本文介绍了一种在APF中使用的新型重复控制策略,它的重复周期只有传统重复控制的一半,可以消除所有的奇次谐波。相比传统的重复控制,本文所提的控制策略具有更快的响应速度和更小的稳态误差;相比传统的谐振控制,它更容易由数字处理器实现。理论分析、仿真和实验结果都证明了这种快速重复控制的有效性和优越性。

  3. Communications and control for electric power systems

    Science.gov (United States)

    Kirkham, H.

    1992-01-01

    A long-term strategy for the integration of new control technologies for power generation and delivery is proposed: the industry would benefit from an evolutionary approach that would adapt to its needs future technologies as well as those that it has so far not heeded. The integrated operation of the entire system, including the distribution system, was proposed as a future goal. The AbNET communication protocols are reviewed, and additions that were made in 1991 are described. In the original network, traffic was controlled by polling at the master station, located at the substation, and routed by a flooding algorithm. In a revised version, the polling and flooding are modified. The question of interfacing low-energy measurement transducers or instrument transformers is considered. There is presently little or no agreement on what the output of optical current transducers (CT's) should be. Appendices deal with the calibration of current transducers; with Delta modulation, a simple means of serially encoding the output of an OCT; and with noise shaping, a method of digital signal processing that trades off the number of bits in a digital sample for a higher number of samples.

  4. Macrofouling control in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ekis, E.W. Jr.; Keoplin-Gall, S.M.; McCarthy, R.E.

    1991-11-01

    Macrofouling of cooling-water systems is one of the more significant and costly problems encountered in the nuclear power industry. Both marine and freshwater macroinvertebrates can be responsible for losses in plant availability because of plugged intakes and heat transfer equipment. There is a greater diversity of macrofouling organisms in marine waters than in fresh waters. Marine macrofouling organisms include barnacles, mollusks, bryozoans, and hydroids. Barnacles are crustaceans with feathery appendages, which allow them to attach to a variety of surfaces. They are a major cause of severe macrofouling because they can remain attached even after death. The major freshwater macrofouling organisms include the Asiatic Clam (Corbicula fluminea) and the newest freshwater macrofouler, the Zebra Mussel (Dreissena polymorpha). The introduction of the Zebra Mussel into the Great Lakes has created economic and ecological problems that will not easily be solved. The threat of intercontinental dispersal of the Zebra Mussel in America is serious. Research programs have been initiated around the country to develop control methods for this macrofouling problem. The various control methodologies can be classified in the following categories: biological, chemical, physical, and mechanical. Laboratory experiments were performed to evaluate the efficacy of Actibrom against mature Zebra Mussels.

  5. Solar Power Station Output Inverter Control Design

    Directory of Open Access Journals (Sweden)

    J. Bauer

    2011-04-01

    Full Text Available The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network.

  6. Adaptive decoupled power control method for inverter connected DG

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Tian, Yanjun; Chen, Zhe

    2014-01-01

    The integration of renewable energy technology is making the power distribution system more flexible, but also introducing challenges for traditional technology. With the nature of intermittent and less inertial, renewable energy-based generations need effective control methods to cooperate...... an adaptive droop control method based on online evaluation of power decouple matrix for inverter connected distributed generations in distribution system. Traditional decoupled power control is simply based on line impedance parameter, but the load characteristics also cause the power coupling, and alter...

  7. Evaluation of power control concepts using the PMAD systems test bed. [Power Management and Distribution

    Science.gov (United States)

    Beach, R. F.; Kimnach, G. L.; Jett, T. A.; Trash, L. M.

    1989-01-01

    The Lewis Research Center's Power Management and Distribution (PMAD) System testbed and its use in the evaluation of control concepts applicable to the NASA Space Station Freedom electric power system (EPS) are described. The facility was constructed to allow testing of control hardware and software in an environment functionally similar to the space station electric power system. Control hardware and software have been developed to allow operation of the testbed power system in a manner similar to a supervisory control and data acquisition (SCADA) system employed by utility power systems for control. The system hardware and software are described.

  8. Simulation Research on Integrated Control of Vehicle Semi-active Suspension and Power Steering%车辆半主动悬架与助力转向集成控制的仿真研究

    Institute of Scientific and Technical Information of China (English)

    汪少华; 陈龙; 袁传义

    2009-01-01

    For coordinating handling stability and ride comfort of vehicle, based on the principle of chassis system dynamics, a combined model for semi-active suspension (SAS) and electric power steering (EPS) is set up for imposing integrated control on the systems of SAS and EPS. Quadratic feedback and PID strategies are used to control the adjustable damping of suspension and the assistant power of EPS respectively. The simulation results show that with integrated control, the handling stability and ride comfort of vehicle are both superior to that with sep-arate control on suspension or steering.%为协调车辆操纵稳定性和行驶平顺性,基于底盘系统动力学原理,建立了半主动悬架和电动助力转向的综合模型,对半主动悬架和电动助力转向系统进行集成控制.运用二次反馈法和PID策略分别对悬架的可调阻尼和转向系统的助力进行控制.仿真结果表明,在集成控制情况下,车辆的操纵稳定性和平顺性均优于悬架或转向单独控制的效果.

  9. Autonomous homing control of a powered parafoil with insufficient altitude.

    Science.gov (United States)

    Tao, Jin; Sun, Qing-Lin; Tan, Pan-Long; Chen, Zeng-Qiang; He, Ying-Ping

    2016-11-01

    In order to realize safe and accurate homing of a powered parafoil under the condition of insufficient initial altitude, a multiphase homing path is designed according to the flight characteristics of the vehicle. With consideration that the traditional control methods cannot ensure the quality of path following because of the nonlinear, large inertial and longtime delay existed in the system and strong disturbances in a complex environment, a homing controller, composed of the vertical and horizontal trajectory tracking controllers, is designed based on active disturbance rejection control (ADRC). Then autonomous homing simulation experiment of the powered parafoil with insufficient altitude is carried on in a windy environment. The simulation results show that the planned multiphase homing trajectory can fulfill the requirements of fixed-point homing and flare landing; the designed homing controller can overcome the influences of uncertain items of the internal and external disturbances, track the desired homing path more rapidly and steadily, and possesses better control performances than traditional PID controllers.

  10. Electric power systems analysis and control

    CERN Document Server

    Saccomanno, Fabio

    2003-01-01

    "Highly relevant and timely in scope, the book is essential reading for anyone associated with electric power systems, including students and teachers of power engineering courses, professionals in the industry, consultants, and researchers."--Jacket.

  11. Optimisation of a storage facility used to effect power control in the PBMR power cycle

    OpenAIRE

    Mathews, Edward A; Pelzer, Ruaan; Matimba, A

    2008-01-01

    This article presents the optimization of a gas storage facility used to effect power control in South Africa's PBMR power cycle. It was shown in the article, a multitank storage facility to affect power control in the PBMR power cyclel, that a multi tank design with heat capacitance improves storage effictiveness, which could make the system cheaper. This storage facility is known as the Inventory Control System (ICS). The focus in this article is to determine an optimum numbe...

  12. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification...... is carried out by comparing the calculation results with detailed time domain simulation results. With the droop parameters as variables in the power flow analysis, their effects on power sharing and secondary voltage regulation can now be analytically studied, and specialized optimization in the upper level...... control can also be made accordingly. Case studies on power sharing and secondary voltage regulation are carried out using proposed power flow analysis....

  13. Modeling and State feedback Control of Three-phase Active Power Filter on Switched System%三相 APF 的切换系统建模与状态反馈控制

    Institute of Scientific and Technical Information of China (English)

    殷文月; 程新功; 宗西举; 张静亮

    2015-01-01

    Three-phase active power filter (APF) is a typical switched affine system for the action of the power switch. The conventional modeling method is based on the linear system theory. Then a novel control procedure for three-phase APF based on switched affine system and quadratic stability is proposed. Firstly, the three-phase APF is built as the switched affine system model. Based on the sufficient condition for the quadratic stability of convex combination, the common Lyapunov function is selected. Then, the active region of the subsystems and switching rules can be defined to assess quadratic stability of the switched system, thus realizing the control of the compensation current and the DC side voltage. Finally, simulation and experimental results have good agreement with the theoretical analysis and demonstrate the validity of this approach.%功率开关的动作使得三相有源电力滤波器(active power filter,APF)成为一种典型切换仿射系统。因此提出了一种基于切换仿射模型和切换系统全局稳定理论的三相APF 的控制方法。首先建立三相 APF 切换仿射模型,为各个切换子系统选取合适的公共李亚普诺夫(Lyapunov)函数,据此划分各个子系统的运行域,构造基于状态反馈的切换规则保证系统在切换控制下二次稳定,从而实现了电流和电压的统一控制。最后仿真和实验结果与理论分析具有良好的一致性。

  14. Junction temperature measurements via thermo-sensitive electrical parameters and their application to condition monitoring and active thermal control of power converters

    DEFF Research Database (Denmark)

    Baker, Nick; Liserre, Marco; Dupont, L.

    2013-01-01

    , successful implementation of these techniques during the actual operation of a device has not yet been achieved. This paper provides an overview of literature where the usage of TSEPs has been hypothesised or realised in realistic power electronic converter setups. Barriers and limitations preventing wider...

  15. Modeling and control of sustainable power systems

    CERN Document Server

    Wang, Lingfeng

    2011-01-01

    The concept of the smart grid promises the world an efficient and intelligent approach of managing energy production, transportation, and consumption by incorporating intelligence, efficiency, and optimality into the power grid. Both energy providers and consumers can take advantage of the convenience, reliability, and energy savings achieved by real-time and intelligent energy management. To this end, the current power grid is experiencing drastic changes and upgrades. For instance, more significant green energy resources such as wind power and solar power are being integrated into the power

  16. Testing power system controllers by real-time simulation

    DEFF Research Database (Denmark)

    Venne, Philippe; Guillaud, Xavier; Sirois, Frédéric

    2007-01-01

    In this paper, we present a number of state-of-the art methods for testing power system controllers based on the use of a real-time power system simulator. After introducing Hypersim, we list and discuss the different means of connection between the controller under tests and the power system...

  17. Priority Control Strategy of VSC-MTDC System for Integrating Wind Power

    Directory of Open Access Journals (Sweden)

    Wen-ning Yan

    2015-01-01

    Full Text Available For the obvious advantages in integrating wind power, multiterminal HVDC transmission system (VSC-MTDC is widely used. The priority control strategy is proposed in this paper considering the penetration rate of wind power for the AC grid. The strategy aims to solve the problems of power allocation and DC voltage control of the DC system. The main advantage of this strategy is that the demands for wind power of different areas can be satisfied and a power reference for the wind power trade can also be provided when wind farms transmit active power to several AC grids through the DC network. The objective is that power is well distributed according to the output power of wind farm with the demand of AC system and satisfactory control performance of DC voltage is obtained.

  18. The Paralleling of High Power High Frequency Amplifier Based on Synchronous and Asynchronous Control

    Institute of Scientific and Technical Information of China (English)

    程荣仓; 刘正之

    2004-01-01

    The vertical position of plasma in the HT-7U Tokamak is inherently unstable. In order to realize active stabilization, the response rate of the high-power high-frequency amplifier feeding the active control coils must be fast enough. This paper analyzes the paralleling scheme of the power amplifier through two kinds of control mode. One is the synchronous control; the other is the asynchronous control. Via the comparison of the two kinds of control mode, both of their characteristics are given in the text. At last, the analyzed result is verified by a small power experiment.

  19. Use of dominant harmonic active filters in high power applications

    Science.gov (United States)

    Cheng, Po-Tai

    The application of power electronics equipment is increasing rapidly. It is estimated that 60% of electrical power will be processed by power electronics equipment by year 2000. These equipments typically require rectifiers for AC-DC power conversion. Due to their nonlinear nature, most rectifiers draw harmonic current from the utility grid. The harmonic current causes higher energy losses, and may excite resonance conditions in the utility grid. Harmonic standards such as IEEE 519 and IEC 1000-3-2 have been proposed to regulate the harmonic current and voltage levels. This work is to develop a dominant harmonic active filter (DHAF) to realize a cost-effective active filtering solution for nonlinear loads in the range of megawatt and above. The DHAF system achieves harmonic isolation at dominant harmonic frequencies, e.g. the 5th and 7th. This approach allows use of low switching frequency and small rating active filter inverters (1%--2% of the load MVA rating) for implementation. Review of conventional passive filters and various active filters based on high bandwidth PWM inverters is provided. The control theory of the DHAF system is presented. Comparison of the DHAF system and other dominant harmonic filtering approach is provided. Simulation results and laboratory prototype test results are presented to validate the effectiveness of the proposed DHAF system.

  20. Variation of UPFC Controllable Parameters during Power Swing and their Impacts on Distance Relay

    DEFF Research Database (Denmark)

    Khodaparast, Jalal; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    Unified Power Flow Controller (UPFC) has impact on the performance of distance relay during power swing. Generally power system’s parameters oscillate during power swing and since UPFC operation depends on some of these parameters (bus voltage, active and reactive power), the UPFC injects...... oscillated series voltage and draws oscillated shunt current. These oscillating series voltage and shunt current influence distance relays, as the impedance seen by a distance relay during power swing changes in UPFC-compensated lines. This paper shows how and why series voltage and shunt current change...... during power swing. Moreover, the admittance swing characteristic is proposed in this paper and effects of series and shunt branches of UPFC on the admittance seen by a distance relay during power swing have been examined. keywords:Admittance, Distance relay, Power Swing, Unified Power Flow Controller...

  1. Advanced Electric Distribution, Switching, and Conversion Technology for Power Control

    Science.gov (United States)

    Soltis, James V.

    1998-01-01

    The Electrical Power Control Unit currently under development by Sundstrand Aerospace for use on the Fluids Combustion Facility of the International Space Station is the precursor of modular power distribution and conversion concepts for future spacecraft and aircraft applications. This unit combines modular current-limiting flexible remote power controllers and paralleled power converters into one package. Each unit includes three 1-kW, current-limiting power converter modules designed for a variable-ratio load sharing capability. The flexible remote power controllers can be used in parallel to match load requirements and can be programmed for an initial ON or OFF state on powerup. The unit contains an integral cold plate. The modularity and hybridization of the Electrical Power Control Unit sets the course for future spacecraft electrical power systems, both large and small. In such systems, the basic hybridized converter and flexible remote power controller building blocks could be configured to match power distribution and conversion capabilities to load requirements. In addition, the flexible remote power controllers could be configured in assemblies to feed multiple individual loads and could be used in parallel to meet the specific current requirements of each of those loads. Ultimately, the Electrical Power Control Unit design concept could evolve to a common switch module hybrid, or family of hybrids, for both converter and switchgear applications. By assembling hybrids of a common current rating and voltage class in parallel, researchers could readily adapt these units for multiple applications. The Electrical Power Control Unit concept has the potential to be scaled to larger and smaller ratings for both small and large spacecraft and for aircraft where high-power density, remote power controllers or power converters are required and a common replacement part is desired for multiples of a base current rating.

  2. Active control of convection

    Energy Technology Data Exchange (ETDEWEB)

    Bau, H.H. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  3. Active power line conditioners design, simulation and implementation for improving power quality

    CERN Document Server

    Revuelta, Patricio Salmeron; Litrán, Salvador Pérez

    2015-01-01

    Active Power Line Conditioners: Design, Simulation and Implementation for Improving Power Quality presents a rigorous theoretical and practical approach to active power line conditioners, one of the subjects of most interest in the field of power quality. Its broad approach offers a journey that will allow power engineering professionals, researchers, and graduate students to learn more about the latest landmarks on the different APLC configurations for load active compensation. By introducing the issues and equipment needs that arise when correcting the lack of power quality in power grids

  4. A Novel Approach in Design of a Fuzzy Based Shunt Active Power Filter for the Enhancement of Power Quality

    Directory of Open Access Journals (Sweden)

    Soumya I C

    2014-03-01

    Full Text Available Active power filters most of the times are employed for elimination of the harmonics created by non-linear loads in power system and for reactive power compensation of linear and non-linear loads. Compensating current is sent by shunt active power filter (SAF at Point of Common Coupling (PCC to mitigate current harmonics in the line. Hence sinusoidal nature of current and voltage waveforms are reintroduced. Usually shunt active power filters are connected in parallel with non-linear and reactive loads. Fuzzy logic controller is used as it doesn’t require complex mathematical model. Filter inductor current is shaped by fuzzy controller so that line current is in phase with and of input voltage shape. Simulation of the proposed filter is carried out using MATLAB/SIMULINK.

  5. Joint Transmit Beamforming and Power Control for CDMA System

    Institute of Scientific and Technical Information of China (English)

    LI Ji-long; CHEN Yu; LI Chun-yuan; ZHANG Ping

    2005-01-01

    Downlink transmit beamforming is a promising technique to reduce interference,and power control is a technique to adjust transmission power to satisfy the link quality.Joint transmission power control and beamforming are proposed to minimize total transmission power.The joint optimization problem is solved by receiver beamforming and power control in virtual uplink.SIR based power control is performed to adjust the power allocation,and transmit beamforming weight vectors are determined by Minimum Variance Distortionless Response(MVDR)criterion.The multipath combining weight vectors are determined by maximum ratio combining criterion.Simulation results show the joint optimization scheme decreases the transmission power,and system performance is enhanced.

  6. Power Control in Multi-cluster Mobile Ad hoc Networks

    Institute of Scientific and Technical Information of China (English)

    JINYanliang; YANGYuhang

    2003-01-01

    Power control gives us many advantages including power saving, lower interference, and efficient channel utilization. We proposed two clustering algorithms with power control for multl-cluster mobile ad hoc networks in this paper. They improve the network throughput and the network stability as compared to other ad hoc networks in which all mobile nodes use the same transmission power. Furthermore, they help in reducing the system power consumption. We compared the performances of the two approaches. Simulation results show that the DCAP (Distributed clustering algorithm with power control) would achieve a better throughput performance and lower power consumption than the CCAP (Centralized clustering algorithm with power control), but it is complicated and liable to be affected by node velocity.

  7. Resistojet control and power for high frequency ac buses

    Science.gov (United States)

    Gruber, Robert P.

    1987-01-01

    Resistojets are operational on many geosynchronous communication satellites which all use dc power buses. Multipropellant resistojets were selected for the Initial Operating Capability (IOC) Space Station which will supply 208 V, 20 kHz power. This paper discusses resistojet heater temperature controllers and passive power regulation methods for ac power systems. A simple passive power regulation method suitable for use with regulated sinusoidal or square wave power was designed and tested using the Space Station multipropellant resistojet. The breadboard delivered 20 kHz power to the resistojet heater. Cold start surge current limiting, a power efficiency of 95 percent, and power regulation of better than 2 percent were demonstrated with a two component, 500 W breadboard power controller having a mass of 0.6 kg.

  8. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the...

  9. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the operational...

  10. Integrated power electronic converters and digital control

    CERN Document Server

    Emadi, Ali; Nie, Zhong

    2009-01-01

    Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T

  11. Control of Power Converters in AC Microgrids

    DEFF Research Database (Denmark)

    Rocabert, Joan; Luna, Alvaro; Blaabjerg, Frede

    2012-01-01

    The enabling of ac microgrids in distribution networks allows delivering distributed power and providing grid support services during regular operation of the grid, as well as powering isolated islands in case of faults and contingencies, thus increasing the performance and reliability of the ele......The enabling of ac microgrids in distribution networks allows delivering distributed power and providing grid support services during regular operation of the grid, as well as powering isolated islands in case of faults and contingencies, thus increasing the performance and reliability...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    damper. Unlike an active power filter for mitigating low-frequency harmonics, the proposed damper dampens resonances at higher frequencies, whose values are dependent on interactions among multiple grid-connected converters and reactive elements of the system. Its control requirements are, therefore......-order resonant controller, in addition to the second-order resonant controller used for resonance damping. Experimental results obtained have confirmed the effectiveness of these controllers, and hence, the feasibility of the active damper.......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. SIMULATION STUDY OF GENERALIZED PREDICTIVE CONTROL FOR TURBINE POWER

    Institute of Scientific and Technical Information of China (English)

    Shi Xiaoping; Li Dongmei

    2004-01-01

    A GPC (generalized predictive control) law is developed to control the power of a turbine, after transforming the nonlinear mathematical model of the power regulation system into a CARIMA(controlled auto-regressive integrated moving average) form. The effect of the new control law is compared with a traditional PID (proportional, integral and differential) control law by numerical simulation. The simulation results verify the effectiveness, the correctness and the advantage of the new control scheme.

  14. Sliding mode control of switching power converters techniques and implementation

    CERN Document Server

    Tan, Siew-Chong; Tse, Chi-Kong

    2011-01-01

    Sliding Mode Control of Switching Power Converters: Techniques and Implementation is perhaps the first in-depth account of how sliding mode controllers can be practically engineered to optimize control of power converters. A complete understanding of this process is timely and necessary, as the electronics industry moves toward the use of renewable energy sources and widely varying loads that can be adequately supported only by power converters using nonlinear controllers.Of the various advanced control methods used to handle the complex requirements of power conversion systems, sliding mode c

  15. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O.P.; Chen, G.P.; Zhang, Y.; El-Metwally, K. [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  16. A scheme to design power controller in wireless network systems

    Science.gov (United States)

    Kong, Shulan; Zhang, Huanshui; Zhang, Zhaosheng

    2007-02-01

    In this Letter, power control problem is firstly studied at an angle of LQG measurement-feedback control problem. A stochastic uplink power control problem is considered for CDMA systems. An effective distributed algorithm is proposed based on stochastic linear quadratic optimal control theory assuming SIR measurements contain white noise. The presented scheme minimizes the sum of the power and the error of SIR. A measurement-feedback power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving the Kalman filter problem for the systems.

  17. A scheme to design power controller in wireless network systems

    Energy Technology Data Exchange (ETDEWEB)

    Kong Shulan [School of Mathematics Science, Qufu Normal University, Qufu 273165, Shandong (China)]. E-mail: shulankong@sina.com; Zhang Huanshui [School of Control Science and Control Engineering, Shandong University, Jinnan 250061, Shandong (China); Zhang Zhaosheng [School of Mathematics Science, Qufu Normal University, Qufu 273165, Shandong (China)

    2007-02-05

    In this Letter, power control problem is firstly studied at an angle of LQG measurement-feedback control problem. A stochastic uplink power control problem is considered for CDMA systems. An effective distributed algorithm is proposed based on stochastic linear quadratic optimal control theory assuming SIR measurements contain white noise. The presented scheme minimizes the sum of the power and the error of SIR. A measurement-feedback power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving the Kalman filter problem for the systems.

  18. Power electronic converters PWM strategies and current control techniques

    CERN Document Server

    Monmasson, Eric

    2013-01-01

    A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

  19. Modeling and Control of Grid Side Converter in Wind Power Generation System Based on Synchronous VFDPC with PLL

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan

    2011-01-01

    Virtual flux oriented direct power control (VFDPC) is combined space vector modulation (SVM) with PI of DC-link voltage, active power and reactive power to control the grid side converter in wind power generation system in this paper. VFDPC has reached good performances with PLL (phase lock loop...

  20. Modeling and Control of Grid Side Converter in Wind Power Generation System Based on Synchronous VFDPC with PLL

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan

    2011-01-01

    Virtual flux oriented direct power control (VFDPC) is combined space vector modulation (SVM) with PI of DC-link voltage, active power and reactive power to control the grid side converter in wind power generation system in this paper. VFDPC has reached good performances with PLL (phase lock loop...

  1. Design of a wind turbine pitch angle controller for power system stabilisation

    DEFF Research Database (Denmark)

    Jauch, Clemens; Islam, S.M.; Sørensen, Poul Ejnar

    2007-01-01

    The design of a PID pitch angle controller for a fixed speed active-stall wind turbine, using the root locus method is described in this paper. The purpose of this controller is to enable an active-stall wind turbine to perform power system stabilisation. For the purpose of controller design...... can effectively contribute to power system stabilisation. (c) 2007 Elsevier Ltd. All rights reserved....

  2. Software-Based Wireless Power Transfer Platform for Various Power Control Experiments

    OpenAIRE

    Sun-Han Hwang; Chung G. Kang; Yong-Ho Son; Byung-Jun Jang

    2015-01-01

    In this paper, we present the design and evaluation of a software-based wireless power transfer platform that enables the development of a prototype involving various open- and closed-loop power control functions. Our platform is based on a loosely coupled planar wireless power transfer circuit that uses a class-E power amplifier. In conjunction with this circuit, we implement flexible control functions using a National Instruments Data Acquisition (NI DAQ) board and algorithms in the MATLAB/...

  3. Optimal Power Control in Wireless Powered Sensor Networks: A Dynamic Game-Based Approach

    Science.gov (United States)

    Xu, Haitao; Guo, Chao; Zhang, Long

    2017-01-01

    In wireless powered sensor networks (WPSN), it is essential to research uplink transmit power control in order to achieve throughput performance balancing and energy scheduling. Each sensor should have an optimal transmit power level for revenue maximization. In this paper, we discuss a dynamic game-based algorithm for optimal power control in WPSN. The main idea is to use the non-cooperative differential game to control the uplink transmit power of wireless sensors in WPSN, to extend their working hours and to meet QoS (Quality of Services) requirements. Subsequently, the Nash equilibrium solutions are obtained through Bellman dynamic programming. At the same time, an uplink power control algorithm is proposed in a distributed manner. Through numerical simulations, we demonstrate that our algorithm can obtain optimal power control and reach convergence for an infinite horizon. PMID:28282945

  4. Smart Energy Systems Laboratory - A Real-Time Control, ICT and Power HIL platform

    DEFF Research Database (Denmark)

    Iov, Florin; Petersen, Lennart

    using a complete low voltage grid implementation in Opal-RT. Moreover, results for hierarchical power balancing and voltage control involving assets connected to MV and LV distribution system are shown. Finally, on-going activities regarding voltage control of large wind power plants are presented....

  5. Wind Powering America FY07 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2008-02-01

    The Wind Powering America FY07 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 30 state wind working groups (welcoming Georgia and Wisconsin in 2007) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 140 members of national and state public and private sector organizations from 39 U.S. states and Canada attended the 6th Annual WPA All-States Summit in Los Angeles in June. WPA's emphasis remains on the rural agricultural sector, which stands to reap the significant economic development benefits of wind energy development. Additionally, WPA continues its program of outreach, education, and technical assistance to Native American communities, public power entities, and regulatory and legislative bodies.

  6. Hierarchical Power Sharing Control in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami Akhuleh, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

    2016-01-01

    Because of the advances in power electronics, DC-based power systems, have been used in industrial applications such as data centers [18], space applications [10], aircraft [12], offshore wind farms, electric vehicles [56], DC home systems [5, 20], and high-voltage DC transmission systems...

  7. Wind Farm Coordinated Control for Power Optimization

    Institute of Scientific and Technical Information of China (English)

    SHU Jin; HAO Zhiguo; ZHANG Baohui; BO Zhiqian

    2011-01-01

    The total wind energy capture would decrease with the aerodynamic interaction among turbines known as wake effect, and the conventional maximum power point track (MPPT) schemes for individual wind turbine generator (WTG) can not maximize the total farm power.

  8. Power system small signal stability analysis and control

    CERN Document Server

    Mondal, Debasish; Sengupta, Aparajita

    2014-01-01

    Power System Small Signal Stability Analysis and Control presents a detailed analysis of the problem of severe outages due to the sustained growth of small signal oscillations in modern interconnected power systems. The ever-expanding nature of power systems and the rapid upgrade to smart grid technologies call for the implementation of robust and optimal controls. Power systems that are forced to operate close to their stability limit have resulted in the use of control devices by utility companies to improve the performance of the transmission system against commonly occurring power system

  9. Variable structure control for maximum wind power extraction

    Energy Technology Data Exchange (ETDEWEB)

    Barambones, O.; Gonzalez de Durana, J.M.; Alcorta, P. [Univ. of the Basque Country, Vitoria (Spain)

    2009-07-01

    The future development of wind power technology will affect the level of impact that wind power will have on the power system. Very large wind farms can pose complex technical challenges while also paving the way for other new technologies that will help with electric grid integration. Increasingly complicated power electronic and computerized control schemes will lead to significant improvements and full controllability of available wind power. Reactive power compensation is an important issue in the control of distribution and transmission systems as it increases feeder system losses, reduces system power factor, and can cause large-amplitude variations in load-side voltage. Moreover, rapid changes in the reactive power consumption of large load centers can cause voltage amplitude oscillations, leading to a change in the electric system real power demand resulting in power oscillation. This paper described a sliding mode vector control for a double fed induction generator (DFIG) drive, used in variable speed wind power generation. The study proposed a new variable structure control which has an integral sliding surface to relax the requirement of the acceleration signal, commonly used in conventional sliding mode speed control techniques. The paper discussed the system modelling, DFIG control scheme, and simulation results. A test of the proposed method based on a two-bladed horizontal axis wind turbine was conducted using the Matlab/Simulink software. In this test, several operating conditions were simulated and the study concluded that satisfactory results were obtained. 14 refs., 5 figs.

  10. Wind Powering America FY06 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2007-02-01

    The Wind Powering America FY06 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 29 state wind working groups (welcoming New Jersey, Indiana, Illinois, and Missouri in 2006) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 120 members of national and state public and private sector organizations from 34 states attended the 5th Annual WPA All-States Summit in Pittsburgh in June.

  11. Zero loss magnetic metamaterials using powered active unit cells.

    Science.gov (United States)

    Yuan, Yu; Popa, Bogdan-Ioan; Cummer, Steven A

    2009-08-31

    We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial with zero loss or even gain can be achieved through an array of such metamaterial cells. This kind of active metamaterial can find use in applications that are performance limited due to material losses.

  12. Power Admission Control with Predictive Thermal Management in Smart Buildings

    DEFF Research Database (Denmark)

    Yao, Jianguo; Costanzo, Giuseppe Tommaso; Zhu, Guchuan

    2015-01-01

    This paper presents a control scheme for thermal management in smart buildings based on predictive power admission control. This approach combines model predictive control with budget-schedulability analysis in order to reduce peak power consumption as well as ensure thermal comfort. First...

  13. 14 CFR 29.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 29.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1142 Auxiliary power unit controls. Means must be provided on the flight deck for...

  14. 14 CFR 25.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 25.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1142 Auxiliary power unit controls. Means must be provided on the flight deck for...

  15. Authority, Power, and the Legitimation of Social Control.

    Science.gov (United States)

    Mitchell, Douglas E.; Spady, William G.

    1983-01-01

    To clarify "power" and "authority," the authors review the concepts' history, examine contemporary concepts of social control, identify four authority modes (based on social relations and controls), derive four power resources from these modes, discuss persuasion and exchange as social control mechanisms, and demarcate…

  16. An Analysis of Variable-Speed Wind Turbine Power-Control Methods with Fluctuating Wind Speed

    Directory of Open Access Journals (Sweden)

    Seung-Il Moon

    2013-07-01

    Full Text Available Variable-speed wind turbines (VSWTs typically use a maximum power-point tracking (MPPT method to optimize wind-energy acquisition. MPPT can be implemented by regulating the rotor speed or by adjusting the active power. The former, termed speed-control mode (SCM, employs a speed controller to regulate the rotor, while the latter, termed power-control mode (PCM, uses an active power controller to optimize the power. They are fundamentally equivalent; however, since they use a different controller at the outer control loop of the machine-side converter (MSC controller, the time dependence of the control system differs depending on whether SCM or PCM is used. We have compared and analyzed the power quality and the power coefficient when these two different control modes were used in fluctuating wind speeds through computer simulations. The contrast between the two methods was larger when the wind-speed fluctuations were greater. Furthermore, we found that SCM was preferable to PCM in terms of the power coefficient, but PCM was superior in terms of power quality and system stability.

  17. Synchronously Driven Power Converter Controller Solution for MedAustron

    CERN Document Server

    Šepetavc, Luka; Tavčar, Rok; Moser, Roland; Gutleber, Johannes

    2011-01-01

    MedAustron is an ion beam cancer therapy and research centre currently under construction in Wiener Neustadt, Austria. This facility features a synchrotron particle accelerator for light ions. Cosylab is closely working together with MedAustron on the development of a power converter controller (PCC) for the 260 deployed power converters – power supplies. Power converters deliver power to magnets used for focusing and steering particle beams. We have designed and developed software and hardware which allows integration of different types of power converters into MedAustron's control system (MACS). PCC's role is to synchronously control and monitor connected power converters. Custom real-time fibre optics link and modular front end devices have been designed for this purpose. Modular front end devices make it possible to interface with almost any type of power converter – with or without built in regulation logic. We implemented realtime mechanisms and a dedicated real-time fibre link to ...

  18. Palm Power Free-Piston Stirling Engine Control Electronics

    Science.gov (United States)

    Keiter, Douglas E.; Holliday, Ezekiel

    2007-01-01

    A prototype 35We, JP-8 fueled, soldier-wearable power system for the DARPA Palm Power program has been developed and tested by Sunpower. A hermetically-sealed 42We Sunpower Free-Piston Stirling Engine (FPSE) with integral linear alternator is the prime mover for this system. To maximize system efficiency over a broad range of output power, a non-dissipative, highly efficient electronic control system which modulates engine output power by varying piston stroke and converts the AC output voltage of the FPSE into 28Vdc for the Palm Power end user, has been designed and demonstrated as an integral component of the Palm Power system. This paper reviews the current status and progress made in developing the control electronics for the Palm Power system, in addition to describing the operation and demonstrated performance of the engine controller in the context of the current JP-8 fueled Palm Power system.

  19. Development of Wind Power Generation Model with DFIG for Varying Wind Speed and Frequency Control for Wind Diesel Power Plant

    Directory of Open Access Journals (Sweden)

    Naresh Kumari

    2016-04-01

    Full Text Available The power generation with non-renewable energy sources has very harmful effects on the environment as well as these sources are depleting. On the other side the renewable energy sources are quite unpredictable source of power. The best trade-off is to use the combination of both kind of sources to make a hybrid system so that their individual power generation constraints can be overcome. The hybrid system taken for analysis in this work comprises of wind and diesel power generation systems. The complete modelling of the system has been done in MATLAB/SIMULINK environment. Doubly fed induction generator (DFIG is used for power generation in wind power system. The modelling has been done considering the changing wind speed and varying load conditions. The mathematical models of DFIG and diesel power generator have been used to develop the simulink model which can be used for analysis of various performances of the system like frequency response and power sharing between different sources with load variation .The generating margin of DFIG is also simulated for the frequency support during varying load conditions .The generating margin is created by the control of active power output from DFIG. Also as the power demand rises the generating margin of DFIG keeps the balance between the power generation and load. Proportional Integral controller has been used for diesel generator plant for frequency control. The controller gains have been optimized with Particle Swarm Optimization technique. The proper selection of controller gains and wind power reserve help to achieve the enhanced frequency response of the hybrid system.

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

    DEFF Research Database (Denmark)

    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...... is built, where the damper is integrated into a grid-connected converter. The results obtained from the experiments demonstrate the stability enhancement of ac power electronics based power systems by the active damper....

  1. ENVIRONMENTAL ASPECTS OF GRID CONNECTED POWER ELECTRONIC CONVERTERS CONTROL

    Directory of Open Access Journals (Sweden)

    Tomasz Chmielewski

    2017-03-01

    Full Text Available This paper presents an unconventional view on power electronic converters control as an important factor in environmental protection. Two distinct features that are provided by the control system, namely harmonics elimination and Fault Ride-Through are addressed herein. The paper provides the discussion on how well designed and robust power converter control can influence the environment in a positive way. One of the shortcomings of power converters is emission of current harmonics which results in supply voltage distortion. The appropriate control minimizes the harmonics content which leads to energy losses reduction, especially in power transformers cores. Fault ride-through is an ability of power converter to remain connected and operating in a grid where the fault occurred. It is of paramount importance for integration of large power renewable energy sources. Shutting down e.g. large wind farm would result in engaging the conventional power plants to fill in the energy production gap.

  2. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by havi...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %).......A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by having...

  3. Reactive power control methods for improved reliability of wind power inverters under wind speed variations

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2012-01-01

    The thermal cycling of power switching devices may lead to failures that compromise the reliability of power converters. Wind Turbine Systems (WTS) are especially subject to severe thermal cycling which may be caused by the wind speed variations or power grid faults. This paper proposes a control...... in the most stressed devices. The possible model-based control system for the proposed method is demonstrated, designed and simulated based on the Three-level Neutral-Point- Clamped (3L-NPC) grid-connected converters. It is concluded that with the proposed reactive power control method, the junction...... method to relieve the thermal cycling of power switching devices under severe wind speed variations, by circulating reactive power among the parallel power converters in a WTS or among the WTS's in a wind park. The amount of reactive power is adjusted to limit the junction temperature fluctuation...

  4. Design of power controller in CDMA system with power and SIR error minimization

    Institute of Scientific and Technical Information of China (English)

    Shulan KONG; Huanshui ZHANG; Zhaosheng ZHANG; Hongxia WANG

    2007-01-01

    In this paper, an uplink power control problem is considered for code division multiple access (CDMA) systems. A distributed algorithm is proposed based on linear quadratic optimal control theory. The proposed scheme minimizes the sum of the power and the error of signal-to-interference ratio (SIR). A power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving a Kalman filter problem.

  5. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...

  6. Investigation of axial power gradients near a control rod tip

    Energy Technology Data Exchange (ETDEWEB)

    Loberg, John, E-mail: John.Loberg@fysast.uu.se [Uppsala University, Department of Physics and Astronomy, Division of Applied Nuclear Physics, Box 525, SE-75120 Uppsala (Sweden); Osterlund, Michael, E-mail: Michael.Osterlund@fysast.uu.se [Uppsala University, Department of Physics and Astronomy, Division of Applied Nuclear Physics, Box 525, SE-75120 Uppsala (Sweden); Bejmer, Klaes-Hakan, E-mail: Klaes-Hakan.Bejmer@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden); Blomgren, Jan, E-mail: Jan.Blomgren@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden); Kierkegaard, Jesper, E-mail: Jesper.Kierkegaar@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden)

    2011-07-15

    Highlights: > Pin power gradients near BWR control rod tips have been investigated. > A control rod tip is modeled in MCNP and compared to simplified 2D/3D geometry. > Small nodes increases pin power gradients; standard nodes underestimates gradients. > The MCNP results are validated against axial gamma scan of a controlled fuel pin. - Abstract: Control rod withdrawal in BWRs induces large power steps in the adjacent fuel assemblies. This paper investigates how well a 2D/3D method, e.g., CASMO5/SIMULATE5 computes axial pin power gradients adjacent to an asymmetrical control-rod tip in a BWR. The ability to predict pin power gradients accurately is important for safety considerations whereas large powers steps induced by control rod withdrawal can cause Pellet Cladding Interaction. The computation of axial pin power gradients axially around a control rod tip is a challenging task for any nodal code. On top of that, asymmetrical control rod handles are present in some BWR designs. The lattice code CASMO requires diagonal symmetry of all control rod parts. This introduces an error in computed pin power gradients that has been evaluated by Monte Carlo calculations. The results show that CASMO5/SIMULATE5, despite the asymmetrical control rod handle, is able to predict the axial pin power gradient within 1%/cm for axial nodal sizes of 15-3.68 cm. However, a nodal size of 3.68 cm still causes underestimations of pin power gradients compared with 1 cm nodes. Furthermore, if conventional node sizes are used, {approx}15 cm, pin power gradients can be underestimated by over 50% compared with 1 cm nodes. The detailed axial pin power profiles from MCNP are corroborated by measured gamma scan data on fuel rods irradiated adjacent to control rods.

  7. PMBLDC motor drive with power factor correction controller

    DEFF Research Database (Denmark)

    George, G.J.; Ramachandran, Rakesh; Arun, N.

    2012-01-01

    This paper presents a boost converter configuration, control scheme and design of single phase power factor controller for permanent magnet brushless DC motor (PMBLDCM) drive. PMBLDC motors are the latest choice of researchers, due to the high efficiency, silent operation, compact size, high...... reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase...... with supply voltage. It uses a boost converter to obtain unity power factor with improved performance. The system includes a speed controller for PMBLDC drive and a voltage controller for boost converter.. The voltage or speed controllers can be realized using proportional integral (PI) controller...

  8. Power factor correction, controlling voltage distortion

    Directory of Open Access Journals (Sweden)

    A. Ceclan

    2008-05-01

    Full Text Available This paper presents, an approach fordetermining optimal sizes of single-tuned passiveharmonic filters among existent capacitor busses ina power system. The proposed method uses EdsaHarmonics Analysis and the obtained results arepresented in detail.

  9. Power system security enhancement with unified power flow controller under multi-event contingency conditions

    National Research Council Canada - National Science Library

    S. Ravindra; Chintalapudi V. Suresh; S. Sivanagaraju; V.C. Veera Reddy

    2017-01-01

    .... An improved teaching learning based optimization (ITLBO) algorithm has been presented. To enhance the system security under contingency conditions in the presence of unified power flow controller (UPFC...

  10. Adaptive Neural Network Algorithm for Power Control in Nuclear Power Plants

    Science.gov (United States)

    Masri Husam Fayiz, Al

    2017-01-01

    The aim of this paper is to design, test and evaluate a prototype of an adaptive neural network algorithm for the power controlling system of a nuclear power plant. The task of power control in nuclear reactors is one of the fundamental tasks in this field. Therefore, researches are constantly conducted to ameliorate the power reactor control process. Currently, in the Department of Automation in the National Research Nuclear University (NRNU) MEPhI, numerous studies are utilizing various methodologies of artificial intelligence (expert systems, neural networks, fuzzy systems and genetic algorithms) to enhance the performance, safety, efficiency and reliability of nuclear power plants. In particular, a study of an adaptive artificial intelligent power regulator in the control systems of nuclear power reactors is being undertaken to enhance performance and to minimize the output error of the Automatic Power Controller (APC) on the grounds of a multifunctional computer analyzer (simulator) of the Water-Water Energetic Reactor known as Vodo-Vodyanoi Energetichesky Reaktor (VVER) in Russian. In this paper, a block diagram of an adaptive reactor power controller was built on the basis of an intelligent control algorithm. When implementing intelligent neural network principles, it is possible to improve the quality and dynamic of any control system in accordance with the principles of adaptive control. It is common knowledge that an adaptive control system permits adjusting the controller’s parameters according to the transitions in the characteristics of the control object or external disturbances. In this project, it is demonstrated that the propitious options for an automatic power controller in nuclear power plants is a control system constructed on intelligent neural network algorithms.

  11. Utility based Power Control with FEC in Hexagonally deployed WSN

    Directory of Open Access Journals (Sweden)

    Rajendran Valli

    2012-03-01

    Full Text Available The fundamental component of resource management in Wireless Sensor Network (WSN is transmitter power control since they are miniature battery powered devices. An efficient power control technique is essential to maintain reliable communication links in WSN and to maintain the battery life of the sensor node and in turn the sensor network. Error control coding (ECC schemes can improve the system performance and has an impact on energy consumption. This paper analyses a game theoretic model with pricing for power control in a sensor network considering ECC for random, square, triangular and hexagonal deployment schemes. The performance of the proposed power control scheme with RS and MIDRS code for WSN is evaluated in terms of utility, and energy consumption. Simulation results show that, for hexagonal deployment scheme, with the inclusion of ECC, the transmitting power of the nodes is reduced thereby saving energy and increasing the network lifetime

  12. A Fuzzy Control System of Turbine Rotate Speed and Power for a Power Plant Simulator

    Institute of Scientific and Technical Information of China (English)

    史小平; 王子才

    2002-01-01

    In this paper, a fuzzy control system of turbine rotate speed and power for a power plant simulator is designed. Rotate speed and power control is a rather important technique in a thermal power plant, because the rotate speed of the turbine rotor and the power of the generator must be enhanced gradually in order to prevent the relative expansion of the cylinder from increasing abruptly. The two parameters of a turbine used to be controlled manually or manual-automatically. To improve the control quality and the automation level, a fuzzy control method is developed for apower plant simulator to fit the DCS (Distributed Control System). The results of practical debugging on the simulator are shown in the paper to demonstrate the correctness and effectiveness of the presented fuzzy control law.

  13. Active control for performance enhancement of electrically controlled rotor

    Institute of Scientific and Technical Information of China (English)

    Lu Yang; Wang Chao

    2015-01-01

    Electrically controlled rotor (ECR) system has the potential to enhance the rotor perfor-mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor perfor-mance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3%rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  14. A NEW METHOD TO CALCULATE COMPENSATION CURRENT IN PARALLEL ACTIVE POWER FILTER

    Directory of Open Access Journals (Sweden)

    Ahmet ALTINTAŞ

    2004-03-01

    Full Text Available Nowadays, active power filter plays an important role in reducing harmonic current and reactive power in power lines. The reliability and effectiveness of an active power filter depends basically on three characteristics. These are the modulation method, the design characteristics of the PWM modulator and the method implemented to generate compensation current. For the last one, there are many proposed methods. Most of them complicated and hence difficult to implement and adjust. In this study, a new method to calculate compensation current is improved and tested in single-phase parallel active power filter controlled by microcontroller. Experimental and simulation results are presented in the paper.

  15. Active Rectifier for Uninterruptable Power Supply

    Science.gov (United States)

    Stepanov, Andrew; Bogdans, Valdis; Suskis, Pavel; Galkin, Ilya

    2010-01-01

    The paper contains analysis of power factor correction circuits that is made in the context of elaboration of uninterruptable power supply system. Various correctors have been estimated analytically, by means of simulation and experimentally. The most significant attention has been paid to the efficiency of the analyzed converters and their compatibility with modular approach to development of power converters.

  16. High Performance Low Cost Digitally Controlled Power Conversion Technology

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes

    2008-01-01

    Digital control of switch-mode power supplies and converters has within the last decade evolved from being an academic subject to an emerging market in the power electronics industry. This development has been pushed mainly by the computer industry that is looking towards digital power management...

  17. Use of Local Dynamic Electricity Prices for Indirect Control of DER Power Units

    DEFF Research Database (Denmark)

    Nørgård, Per Bromand; Isleifsson, Fridrik Rafn

    2013-01-01

    The regulation capability that may be provided by the individual small-scale distributed energy resources (DER power units) may be insignificant. However, the aggregated response from a large number of DER power units can be significant and thereby provide valuable system services to the power...... wind power, solar power, flexible load and electrical storage. The local power price generation is based on the actual Nord Pool DK2 Spot prices on hourly basis as the quasi-stationary global electricity price, and the local SYSLAB's power exchange with the national grid as basis for the dynamic price...... electricity prices for indirect control of active power. The local, dynamic electricity prices are realised as dynamic adjustments of the quasi-stationary global power price. The aims of the dynamic price adjustments are to prevent overloading of the grid, to reduce the grid power losses and to regulate...

  18. A Vector Control for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    Science.gov (United States)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation due to high efficiently for wind energy capture. An inverter system is required to control wind turbine speed and power factor in those generators. The inverter rating of the synchronous generator equals to generator rating. However, DFIG has the advantage that the inverter rating is about 25% to the generator rating. The paper describes a vector control of DFIG inter-connected to power line. The performance of proposed vector control is examined using power system simulation software PSCAD/EMTDC for the DFIG inter-connected to 6.6kv distribution line. The results show good dynamic responses and high accuracy to the stator active power control and the stator reactive power control.

  19. Microcomputer Control of a Hydraulic Power Element.

    Science.gov (United States)

    1986-12-01

    Electrohydraulic (EHD) Servovalves .................... 9 3. Advantages of EHD Servovalves .......................................... 10 4. Control System Types ................................. 10...positional control with less error. [Ref. 3:pp. 1-21 4. Control System Types Control systems are the means by which servovalves can be used to obtain a

  20. Economic Concerns in Optimal Power Dispatch in the Presence of a Generalized Unified Power Flow Controller under Practical Constraints

    Science.gov (United States)

    Suresh, Chintalapudi V.; Sivanagaraju, Sirigiri; Reddy, P. Umapathi

    2016-09-01

    In power system restructuring, pricing the electrical power plays a vital role in cost allocation between suppliers and consumers. In optimal power dispatch problem, not only the cost of active power generation but also the costs of reactive power generated by the generators, shunt capacitors, transmission losses and device investment costs should be considered. In this paper, a more realistic multi-fuel total cost objective is formulated by considering all the above mentioned costs. As the characteristics of reactive power cost curve are similar to that of active power cost curve, a non-convex reactive power cost function is formulated. The formulated cost function is optimized by satisfying equality, in-equality and practical constraints and also device limits using the proposed uniform distributed two-stage particle swarm optimization. In this paper, power injection model of generalized unified power flow controller (GUPFC) including converter switching losses is presented. The proposed objective functions are optimized in the presence of UPFC and GUPFC and finally suitable device is identified for the standard IEEE-30 bus test system.

  1. Power-Based Control for a Bidirectional AC-DC Power Converter

    NARCIS (Netherlands)

    del Puerto Flores, Dunstano; Scherpen, Jacquelien M.A.

    2011-01-01

    In many electrical applications it is indispensable that the power converter can operate as a generating or rectifier unit, and the controller must be able to handle this bidirectional power flow. An application example is the doubly fed induction machine, where power can flow in both directions thr

  2. Automaticity or active control

    DEFF Research Database (Denmark)

    Tudoran, Ana Alina; Olsen, Svein Ottar

    This study addresses the quasi-moderating role of habit strength in explaining action loyalty. A model of loyalty behaviour is proposed that extends the traditional satisfaction–intention–action loyalty network. Habit strength is conceptualised as a cognitive construct to refer to the psychologic......, respectively, between intended loyalty and action loyalty. At high levels of habit strength, consumers are more likely to free up cognitive resources and incline the balance from controlled to routine and automatic-like responses.......This study addresses the quasi-moderating role of habit strength in explaining action loyalty. A model of loyalty behaviour is proposed that extends the traditional satisfaction–intention–action loyalty network. Habit strength is conceptualised as a cognitive construct to refer to the psychological...... aspects of the construct, such as routine, inertia, automaticity, or very little conscious deliberation. The data consist of 2962 consumers participating in a large European survey. The results show that habit strength significantly moderates the association between satisfaction and action loyalty, and...

  3. Wind farm non-linear control for damping electromechanical oscillations of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, R.D. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata, CC 91, 1900 La Plata (Argentina); Laboratorio de Electronica. Facultad de Ingenieria, Universidad Nacional de la Patagonia San Juan Bosco, Ciudad Universitaria, Km. 4, 9000 Comodoro Rivadavia (Argentina); Battaiotto, P.E. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata, CC 91, 1900 La Plata (Argentina); Mantz, R.J. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, CICpba, Universidad Nacional de La Plata, CC 91, 1900 La Plata (Argentina)

    2008-10-15

    This paper deals with the non-linear control of wind farms equipped with doubly fed induction generators (DFIGs). Both active and reactive wind farm powers are employed in two non-linear control laws in order to increase the damping of the oscillation modes of a power system. The proposed strategy is derived from the Lyapunov Theory and is independent of the network topology. In this way, the strategy can be added to the central controller as another added control function. Finally, some simulations, showing the oscillation modes of a power system, are presented in order to support the theoretical considerations demonstrating the potential contributions of both control laws. (author)

  4. Choosing Actuators for Automatic Control Systems of Thermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunov, A. I., E-mail: gor@tornado.nsk.ru [JSC “Tornado Modular Systems” (Russian Federation); Serdyukov, O. V. [Siberian Branch of the Russian Academy of Sciences, Institute of Automation and Electrometry (Russian Federation)

    2015-03-15

    Two types of actuators for automatic control systems of thermal power plants are analyzed: (i) pulse-controlled actuator and (ii) analog-controlled actuator with positioning function. The actuators are compared in terms of control circuit, control accuracy, reliability, and cost.

  5. Power Control in Wireless Sensor Networks with Variable Interference

    Directory of Open Access Journals (Sweden)

    Michele Chincoli

    2016-01-01

    Full Text Available Adaptive transmission power control schemes have been introduced in wireless sensor networks to adjust energy consumption under different network conditions. This is a crucial goal, given the constraints under which sensor communications operate. Power reduction may however have counterproductive effects to network performance. Yet, indiscriminate power boosting may detrimentally affect interference. We are interested in understanding the conditions under which coordinated power reduction may lead to better spectrum efficiency and interference mitigation and, thus, have beneficial effects on network performance. Through simulations, we analyze the performance of sensor nodes in an environment with variable interference. Then we study the relation between transmission power and communication efficiency, particularly in the context of Adaptive and Robust Topology (ART control, showing how appropriate power reduction can benefit both energy and spectrum efficiency. We also identify critical limitations in ART, discussing the potential of more cooperative power control approaches.

  6. Model-free adaptive control of advanced power plants

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  7. Model-free adaptive control of advanced power plants

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  8. Optimization and Control of Electric Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lesieutre, Bernard C. [Univ. of Wisconsin, Madison, WI (United States); Molzahn, Daniel K. [Univ. of Wisconsin, Madison, WI (United States)

    2014-10-17

    The analysis and optimization needs for planning and operation of the electric power system are challenging due to the scale and the form of model representations. The connected network spans the continent and the mathematical models are inherently nonlinear. Traditionally, computational limits have necessitated the use of very simplified models for grid analysis, and this has resulted in either less secure operation, or less efficient operation, or both. The research conducted in this project advances techniques for power system optimization problems that will enhance reliable and efficient operation. The results of this work appear in numerous publications and address different application problems include optimal power flow (OPF), unit commitment, demand response, reliability margins, planning, transmission expansion, as well as general tools and algorithms.

  9. Automated electric power management and control for Space Station Freedom

    Science.gov (United States)

    Dolce, James L.; Mellor, Pamela A.; Kish, James A.

    1990-01-01

    A comprehensive automation design is being developed for Space Station Freedom's electric power system. It strives to increase station productivity by applying expert systems and conventional algorithms to automate power system operation. An integrated approach to the power system command and control problem is defined and used to direct technology development in: diagnosis, security monitoring and analysis, battery management, and cooperative problem-solving for resource allocation. The prototype automated power system is developed using simulations and test-beds.

  10. Power flow control using distributed saturable reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrovski, Aleksandar D.

    2016-02-13

    A magnetic amplifier includes a saturable core having a plurality of legs. Control windings wound around separate legs are spaced apart from each other and connected in series in an anti-symmetric relation. The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the plurality of control windings is substantially equal to the biasing magnetic flux flowing into a second of the plurality of control windings. The flow of the control current through each of the plurality of control windings changes the reactance of the saturable core reactor by driving those portions of the saturable core that convey the biasing magnetic flux in the saturable core into saturation. The phasing of the control winding limits a voltage induced in the plurality of control windings caused by a magnetic flux passing around a portion of the saturable core.

  11. PowerBuilder中使用OLE对象实现FLV视频文件的播放%Using ActiveX Control to Achieve Playing FLV Video Files in PowerBuilder

    Institute of Scientific and Technical Information of China (English)

    向隅

    2010-01-01

    FLV流媒体格式是目前网站上流行的一种视频格式,它利用了网页上广泛使用的Flash Player平台.只要网站的访问者能看Flash动画,就能看FLV格式视频,不需再额外安装其它视频插件.以Windows XP作为开发平台,详细说明了在PowerBuilder中实现播放FLV视频文件的方法.

  12. Modeling & Analysis of Shunt Active Power Filter Using IRP Theory Fed to Induction Drive

    Directory of Open Access Journals (Sweden)

    PABBISETTY SAI SUJATHA

    2014-10-01

    Full Text Available Utility distribution networks have sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial losses. Because of sensitivity of consumers on power quality and advancement in power electronics. Active power filter technology is the most efficient way to compensate reactive power and cancel out low order harmonics generated by nonlinear loads. The shunt active power filter was considered to be the most basic configuration for the APF. This paper reviews the basic principle of shunt active power filter, along with the current tracking circuit based on the instantaneous reactive power theory and the main circuit performing as an inverter with PWM hysteresis control. The instantaneous active and reactive current component (id-iq method and instantaneous active and reactive power (p-q method are two control strategies which are extensively used in active filters. A shunt active filter based on the instantaneous active and reactive current component (id-iq method is proposed. This method aims to compensate harmonic and first harmonic unbalance. A Comprehensive control method is analyzed and a harmonic Compensation simulation is conducted, the result of which verifies The harmonic detection algorithm is well-proposed and the power Quality of the grid is overall-enhanced. The results are obtained using MATLAB/SIMULINK software.

  13. Integrated low power digital gyro control electronics

    Science.gov (United States)

    M'Closkey, Robert (Inventor); Challoner, A. Dorian (Inventor); Grayver, Eugene (Inventor); Hayworth, Ken J. (Inventor)

    2005-01-01

    Embodiments of the invention generally encompass a digital, application specific integrated circuit (ASIC) has been designed to perform excitation of a selected mode within a vibratory rate gyroscope, damping, or force-rebalance, of other modes within the sensor, and signal demodulation of the in-phase and quadrature components of the signal containing the angular rate information. The ASIC filters dedicated to each channel may be individually programmed to accommodate different rate sensor designs/technology or variations within the same class of sensors. The ASIC architecture employs a low-power design, making the ASIC, particularly suitable for use in power-sensitive applications.

  14. Feasibility Study B-1 Power Controller.

    Science.gov (United States)

    1979-11-01

    Study performed by the Autonetics Strategic Systems Division ( ASSD ) of Rockwell International on Contract N62269-79-C-0294. The objective of this study...Modify the design of the ASSD B-1 SSPC, Part Number 12880-507-1, to be a 115 Vac quadruple SSPC unit, with a SOSTEL compatible interface. 3.1.2 115 Vac...Primary Power Modifications. The ASSD SSPC Unit, Appendix A, contains four identical PC’s operating from 230 Vac primary power. Referring to Figure 1

  15. Control of Fuel Cell Power System

    OpenAIRE

    KOCALMIŞ BİLHAN, Ayşe; Wang, Caisheng

    2017-01-01

    In recent years, it is gettingattention for renewable energy sources such as Fuel Cell (FC), batteries,ultracapacitors or photovoltaic panels (PV) for distributed power generationsystems (DG) or electrical vehicles. This paper proposes a DC/DC converter andDC/AC inverter scheme to combine the Fuel Cell Stack (FC). The power systemconsist of a FC stack, a DC/DC converter, inverter and load. A FC mostly couldnot produce necessary output voltage, the DC/DC boost converter is used forobtaining th...

  16. Multiagent based protection and control in decentralized electric power systems

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Veloso, Manuela

    2010-01-01

    created interesting possibilities for application of intelligent systems such as multiagent systems for control and automation in electric power systems. This paper describes work on designing a multiagent system for protection and control of electric power distribution networks.It demonstrates how......Electric power systems are going through a major change both in their physical and control structure. A large num- ber of small and geographically dispersed power generation units (e.g., wind turbines, solar cells, plug-in electric cars) are replacing big centralized power plants. This shift has...... explicit modeling of capabilities, states, roles and role transition in agents can capture the control and automation in electric power systems. We present illustrative results from using our proposed schema in realistic simulations....

  17. Multiagent based protection and control in decentralized electric power systems

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Veloso, Manuela

    2010-01-01

    Electric power systems are going through a major change both in their physical and control structure. A large num- ber of small and geographically dispersed power generation units (e.g., wind turbines, solar cells, plug-in electric cars) are replacing big centralized power plants. This shift has...... created interesting possibilities for application of intelligent systems such as multiagent systems for control and automation in electric power systems. This paper describes work on designing a multiagent system for protection and control of electric power distribution networks.It demonstrates how...... explicit modeling of capabilities, states, roles and role transition in agents can capture the control and automation in electric power systems. We present illustrative results from using our proposed schema in realistic simulations....

  18. Power control for wind turbines in weak grids: Concepts development

    DEFF Research Database (Denmark)

    Bindner, H.

    1999-01-01

    and analyze methods and technologies for making it viable to utilize more of the wind potential in remote areas. The suggestion is to develop a power control concept for wind turbines which will even out thepower fluctuations and make it possible to increase the wind energy penetration. The main options...... will make wind power more firm and possible to connect to weaker grids. So, when the concept is matured, theexpectation is that for certain wind power installations, the cost of the power control is paid back as added wind power capacity value and saved grid reinforcement costs. Different systems...... for controlling the power output from a wind farm connected to aweak grid have been investigated. The investigation includes development of different control strategies, use of different storage types, development of a framework for comparing different options and tools needed as part of the framework...

  19. Evaluation of power control with different electrical and control concept of wind farm

    DEFF Research Database (Denmark)

    Margaris, Ioannis; Hansen, Anca Daniela

    This report investigates the impact of wind power in non interconnected power systems with increasing wind power penetration. Issues such as power fluctuations, short circuits and FRT capability of wind turbines and frequency control support are under focus. The study case of Rhodes power system...

  20. EDITORIAL: Power is nothing without control Power is nothing without control

    Science.gov (United States)

    Demming, Anna

    2012-04-01

    China have shown that they can fabricate well aligned arrays of ZnO nanorods as long as 10 μm by using a preheating hydrothermal treatment [5.] The dimensions and orientations of the nanorod arrays are particularly well suited to technological applications. Researchers in the US have enhanced the gas-sensing performance of SnO2 single-crystal nanostructures by fabricating nanowires with a segmented morphology [6]. The low-diameter sections allow an optimum ratio of the radius to the Debye length. At the same time, the structures are sufficiently robust to avoid the problems associated with manipulating extremely narrow nanowires. It has been suggested that differences in fabrication methods such as annealing parameters can affect the photoluminescence from silicon quantum dots. Hao and Shen from Shanghai Jiao Tong University in China combined their data on silicon dots annealed in oxygen with that of silicon dots annealed in hydrogen and argon and used analysis of the results to identify the photoluminescence mechanism [7]. The work shows how annealing can be used to control photoluminescence properties by modifying the defect density through annealing treatment. Defects play an important role in tailoring the properties of graphene to maximise the materials potential in electronics and spintronics. Atomistic simulations of these sorts of systems can face problems due to the shear size of the calculations. Researchers in Brazil integrated a number of modelling approaches to propose a true spin filter based on realistic boron-doped zigzag singly hydrogen passivated graphene nanoribbons up to 450 nm in length [8]. The authors explain the excellent spin filtering performance in terms of different scattering probabilities at the impurity site for majority and minority spins, which consequently leads to different localization lengths. Carbon-based nanomaterials have catalysed enormous activity in nanoscale science and technology research. As Journet et al describe in their

  1. Development of the power control system for semiconductor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Suk; Kim, Cheol Jung

    1997-12-01

    For the first year plan of this program, we developed the power control system for semiconductor lasers. We applied the high-current switching mode techniques to fabricating a power control system. Then, we investigated the direct side pumping techniques with GaA1As diode laser bars to laser crystal without pumping optics. We obtained 0.5W average output power from this DPSSL. (author). 54 refs., 3 tabs., 18 figs.

  2. Design and Control of a Powered Transfemoral Prosthesis

    OpenAIRE

    Sup, Frank; Bohara, Amit; Goldfarb, Michael

    2008-01-01

    The paper describes the design and control of a transfemoral prosthesis with powered knee and ankle joints. The initial prototype is a pneumatically actuated powered-tethered device, which is intended to serve as a laboratory test bed for a subsequent self-powered version. The prosthesis design is described, including its kinematic optimization and the design of a three-axis socket load cell that measures the forces and moments of interaction between the socket and prosthesis. A gait controll...

  3. Reactive power control with CHP plants - A demonstration

    DEFF Research Database (Denmark)

    Nyeng, Preben; Østergaard, Jacob; Andersen, Claus A.;

    2010-01-01

    power rating of 7.3 MW on two synchronous generators. A closed-loop control is implemented, that remote controls the CHP plant to achieve a certain reactive power flow in a near-by substation. The solution communicates with the grid operator’s existing SCADA system to obtain measurements from...

  4. Adaptive voltage control in power systems modeling, design and applications

    CERN Document Server

    Fusco, Giuseppe

    2006-01-01

    Large-scale power cuts in both North America and Europe emphasised the need to maintain an adequate supply of high-quality electricity. This book offers information on the relatively low-cost of doing so using self-regulating control mechanisms. It is of interest to the practising power/control engineer and to academics needing industrial inputs.

  5. neural network based load frequency control for restructuring power ...

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... the system in the back propagation chain used in controller training. For this ... power systems. Different types of controllers ... role to allow power exchanges and to supply bet- ter conditions for the ... To solve all these problems in the above men- ..... term load forecasting using generalized neural network ...

  6. A Wolf Pack Algorithm for Active and Reactive Power Coordinated Optimization in Active Distribution Network

    Science.gov (United States)

    Zhuang, H. M.; Jiang, X. J.

    2016-08-01

    This paper presents an active and reactive power dynamic optimization model for active distribution network (ADN), whose control variables include the output of distributed generations (DGs), charge or discharge power of energy storage system (ESS) and reactive power from capacitor banks. To solve the high-dimension nonlinear optimization model, a new heuristic swarm intelligent method, namely wolf pack algorithm (WPA) with better global convergence and computational robustness, is adapted so that the network loss minimization can be achieved. In this paper, the IEEE33-bus system is used to show the effectiveness of WPA technique compared with other techniques. Numerical tests on the modified IEEE 33-bus system show that WPA for active and reactive multi-period optimization of ADN is exact and effective.

  7. High-power CSI-fed induction motor drive with optimal power distribution based control

    Science.gov (United States)

    Kwak, S.-S.

    2011-11-01

    In this article, a current source inverter (CSI) fed induction motor drive with an optimal power distribution control is proposed for high-power applications. The CSI-fed drive is configured with a six-step CSI along with a pulsewidth modulated voltage source inverter (PWM-VSI) and capacitors. Due to the PWM-VSI and the capacitor, sinusoidal motor currents and voltages with high quality as well as natural commutation of the six-step CSI can be obtained. Since this CSI-fed drive can deliver required output power through both the six-step CSI and PWM-VSI, this article shows that the kVA ratings of both the inverters can be reduced by proper real power distribution. The optimal power distribution under load requirements, based on power flow modelling of the CSI-fed drive, is proposed to not only minimise the PWM-VSI rating but also reduce the six-step CSI rating. The dc-link current control of the six-step CSI is developed to realise the optimal power distribution. Furthermore, a vector controlled drive for high-power induction motors is proposed based on the optimal power distribution. Experimental results verify the high-power CSI-fed drive with the optimal power distribution control.

  8. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  9. Reactive power control of wind-diesel-micro-hydro hybrid power systems using matlab/simulink

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, R.C.; Bhatti, T.S.; Kothari, D.P.; Bhat, S. [Birla Inst. of Technology and Science, Pilani (India); Indian Inst. of Technology, New Delhi (India). Centre for Energy Studies; Visvesvaraya National Inst. of Technology, Nagpur (IN). Dept. of Electrical Engineering)

    2005-07-01

    This paper presents reactive power control of isolated wind-diesel-micro-hydro hybrid power system for realistic load disturbance using matlab/simulink. The mathematical model of the system based on matlab/simulink is developed. Reactive power control performance is compared using three different types of Static VAR Compensators (SVC). Transient responses for step plus normally distributed or band limited white noise random change in load have also been presented in this paper. (Author)

  10. Maximum Power Point Tracking and Reactive Power Control of Single Stage Grid Connected Photovoltaic System

    OpenAIRE

    2011-01-01

    Single-stage grid-connected Photovoltaic (PV) systems have advantages such as simple topology, high efficiency, etc. However, since all the control objectives such as the maximum power point tracking (with the utility voltage, and harmonics reduction for output current need to be considered simultaneously, the complexity of the control scheme is much increased. In this paper a new type of grid connected photovoltaic (PV) system with Maximum Power Point Tracking (MPPT) and reactive power simul...

  11. Regime-based supervisory control to reduce power fluctuations from offshore wind power plants

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Cutululis, Nicolaos Antonio; Trombe, Pierre-Julien

    2013-01-01

    of production, hence revenue for the wind farm operator. On the other hand, progresses in short term forecasting, together with the increasing use of probabilistic forecasting can help in achieving efficient power fluctuations reduction with minimum lost production. Here we present supervisory control concepts...... that consider different wind power regimes to derive control setpoints by using a Markov-Switching AutoRegressive model. We evaluate the performance versus measured data in terms of power ramp characteristics and energy efficiency....

  12. A Hybrid Optimization Method for Reactive Power and Voltage Control Considering Power Loss Minimization

    DEFF Research Database (Denmark)

    Liu, Chengxi; Qin, Nan; Bak, Claus Leth;

    2015-01-01

    This paper proposes a hybrid optimization method to optimally control the voltage and reactive power with minimum power loss in transmission grid. This approach is used for the Danish automatic voltage control (AVC) system which is typically a non-linear non-convex problem mixed with both continu...

  13. Analysis, design, and experimental evaluation of power calculation in digital droop-controlled parallel microgrid inverters

    DEFF Research Database (Denmark)

    Gao, Ming-zhi; Chen, Min; Jin, Cheng

    2013-01-01

    Parallel operation of distributed generation is an important topic for microgrids, which can provide a highly reliable electric supply service and good power quality to end customers when the utility is unavailable. However, there is a well-known limitation: the power sharing accuracy between...... distributed generators in a parallel operation. Frequency and voltage droop is a well-established control method for improving power sharing performance. In this method, the active and reactive power calculations are used to adjust the frequency and amplitude of the output voltage. This paper describes...... the digital implementation of a droop method, and analyzes the influence of power calculation on droop method performance. According to the analysis, the performance of droop control in a digital control system is limited by the accuracy and speed of the power calculation method. We propose an improved power...

  14. Parallel power electronics filters in three-phase four-wire systems principle, control and design

    CERN Document Server

    Wong, Man-Chung; Lam, Chi-Seng

    2016-01-01

    This book describes parallel power electronic filters for 3-phase 4-wire systems, focusing on the control, design and system operation. It presents the basics of power-electronics techniques applied in power systems as well as the advanced techniques in controlling, implementing and designing parallel power electronics converters. The power-quality compensation has been achieved using active filters and hybrid filters, and circuit models, control principles and operational practice problems have been verified by principle study, simulation and experimental results. The state-of-the-art research findings were mainly developed by a team at the University of Macau. Offering background information and related novel techniques, this book is a valuable resource for electrical engineers and researchers wanting to work on energy saving using power-quality compensators or renewable energy power electronics systems. .

  15. A Control Strategy for Single-phase Grid-Connected Inverter with Power Quality Regulatory Function

    Directory of Open Access Journals (Sweden)

    Luo Ling

    2013-07-01

    Full Text Available A single-phase grid-connected inverter system based on LCL filter is established,which combines the features of inverter and active power filter. A composite control strategy for grid-connected inverter with the function of implementing reactive power compensation and harmonic compensation in the grid-connected power generation is proposed. Firstly, grid-connected inverter system structure and model is analyzed. A quasi-Proportional Resonant control method to gain the control of grid-connected fundamental wave current containing reactive power compensation current as well as the control of harmonic compensation currents is put forward; then the calculation methods of  composite control command current based on both second order generalized integrator-quadrature signal generator (SOGI-QSG and instantaneous reactive power theory are given. Finally, the effectiveness of the control strategy proposed in this paper is verified by simulation.

  16. Hybrid zero-voltage switching (ZVS) control for power inverters

    Science.gov (United States)

    Amirahmadi, Ahmadreza; Hu, Haibing; Batarseh, Issa

    2016-11-01

    A power inverter combination includes a half-bridge power inverter including first and second semiconductor power switches receiving input power having an intermediate node therebetween providing an inductor current through an inductor. A controller includes input comparison circuitry receiving the inductor current having outputs coupled to first inputs of pulse width modulation (PWM) generation circuitry, and a predictive control block having an output coupled to second inputs of the PWM generation circuitry. The predictive control block is coupled to receive a measure of Vin and an output voltage at a grid connection point. A memory stores a current control algorithm configured for resetting a PWM period for a switching signal applied to control nodes of the first and second power switch whenever the inductor current reaches a predetermined upper limit or a predetermined lower limit.

  17. Advanced and intelligent control in power electronics and drives

    CERN Document Server

    Blaabjerg, Frede; Rodríguez, José

    2014-01-01

    Power electronics and variable frequency drives are continuously developing multidisciplinary fields in electrical engineering, and it is practically not possible to write a book covering the entire area by one individual specialist. Especially by taking account the recent fast development in the neighboring fields like control theory, computational intelligence and signal processing, which all strongly influence new solutions in control of power electronics and drives. Therefore, this book is written by individual key specialist working on the area of modern advanced control methods which penetrates current implementation of power converters and drives. Although some of the presented methods are still not adopted by industry, they create new solutions with high further research and application potential. The material of the book is presented in the following three parts: Part I: Advanced Power Electronic Control in Renewable Energy Sources (Chapters 1-4), Part II: Predictive Control of Power Converters and D...

  18. Power control and management of the grid containing largescale wind power systems

    Science.gov (United States)

    Aula, Fadhil Toufick

    The ever increasing demand for electricity has driven many countries toward the installation of new generation facilities. However, concerns such as environmental pollution and global warming issues, clean energy sources, high costs associated with installation of new conventional power plants, and fossil fuels depletion have created many interests in finding alternatives to conventional fossil fuels for generating electricity. Wind energy is one of the most rapidly growing renewable power sources and wind power generations have been increasingly demanded as an alternative to the conventional fossil fuels. However, wind power fluctuates due to variation of wind speed. Therefore, large-scale integration of wind energy conversion systems is a threat to the stability and reliability of utility grids containing these systems. They disturb the balance between power generation and consumption, affect the quality of the electricity, and complicate load sharing and load distribution managing and planning. Overall, wind power systems do not help in providing any services such as operating and regulating reserves to the power grid. In order to resolve these issues, research has been conducted in utilizing weather forecasting data to improve the performance of the wind power system, reduce the influence of the fluctuations, and plan power management of the grid containing large-scale wind power systems which consist of doubly-fed induction generator based energy conversion system. The aims of this research, my dissertation, are to provide new methods for: smoothing the output power of the wind power systems and reducing the influence of their fluctuations, power managing and planning of a grid containing these systems and other conventional power plants, and providing a new structure of implementing of latest microprocessor technology for controlling and managing the operation of the wind power system. In this research, in order to reduce and smooth the fluctuations, two

  19. Modelling and Control Design of Unified Power Flow Controller for Various Control Strategies

    Directory of Open Access Journals (Sweden)

    T. Nireekshana

    2010-11-01

    Full Text Available Unified Power Flow Controller (UPFC is used to control the power flow in the transmission systems by controlling the impedance, voltage magnitude and phase angle. This controller offers advantages in terms of static and dynamic operation of the power system. It also brings in new challenges in power electronics and power system design. The basic structure of the UPFC consists of two voltage source inverter (VSI; where one converter is connected in parallel to the transmission line while the other is in series with the transmission line. The aim of the paper is to develop a control strategy for UPFC, modeling UPFC using MATLAB/SIMULINK and to analyze the control strategy to use the series voltage injection and shunt current injection for UPFC control. To simplify the design procedure we carry out the design for the series and shunt branches separately.In each case, a simple equivalent circuit represents the external system. The design has to be validated when the various subsystems are integrated.

  20. Application of Newton's optimal power flow in voltage/reactive power control

    Energy Technology Data Exchange (ETDEWEB)

    Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

    1990-11-01

    This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.