Sample records for active power control

  1. Active Power Filter Using Predicted Current Control

    Xiaojie, Y.; Pivoňka, P.; Valouch, Viktor


    Roč. 46, č. 1 (2001), s. 41-50. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : active power filter * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    Ela, E.; Gevorgian, V.; Fleming, P.; Zhang, Y. C.; Singh, M.; Muljadi, E.; Scholbrook, A.; Aho, J.; Buckspan, A.; Pao, L.; Singhvi, V.; Tuohy, A.; Pourbeik, P.; Brooks, D.; Bhatt, N.


    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.

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

    Samuelsson, O.


    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

    王莉娜; 罗安


    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. Indirect control of a single-phase active power filter

    Mihai CULEA


    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.

  6. A New Multilevel Active Power Filter Using Switches Meticulously Controlled

    Zoubir Zahzouh


    Full Text Available Shunt active power filter based on multilevel inverter is used to compensate the power factor and to delete the harmonics. This one permits to reduce the inverse voltages applied to the filter switches and their switching frequencies. Nevertheless, the high number of used switches requires a complicated controller and increases the switching losses; where the necessity of finding another resolution system. In this work a new topology of multilevel inverter is proposed as a shunt active power filter using two IGBT transistors in series of opposite sense meticulously controlled by a parallel control algorithm, with the concept of reduced number of six switches which are able to create five levels of the output voltage. This system substute the classical system of eight switches. The harmonic currents identification is carried out using the instantaneous active and reactive power method. The simulation is performed using Matlab/Simulink. The obtained results show that the filtering performances are well enhanced.

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

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


    more practical control strategy appears to be to minimise the weighted sum of squared forces and velocities below the mounts, which gives near-optimal performance in simulations. These theoretical results are supported by experiments with a real-time control system. The actuator and sensor requirements...... 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 the...... contributions to the transmitted power in the various degrees of freedom can be clearly understood. It has also been found, however, that an active control system which minimises a practical estimate of transmitted power, calculated from the product of the axial forces and velocities under the mounts, can give...

  8. Design and control of hybrid active power filters

    Lam, Chi-Seng


    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...

  9. Model based active power control of a wind turbine

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


    In recent decades there has been increasing interest in green energies, of which wind energy is one of the most important. Wind turbines are the most common wind energy conversion systems and are hoped to be able to compete with traditional power plants in near future. This demands better...... technology to increase competitiveness of the wind power plants. One way to increase competitiveness of wind power plants is to offer grid services (also called ancillary services) that are normally offered by traditional power plants. One of the ancillary services is called reserve power. There are instants...... 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...

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

    Abouelmahjoub Y.


    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.

  11. A predictive control algorithm for an active three-phase power filter

    R.V. Vlasenko; Bialobrzeski, O. V.


    The paper deals with grid connection circuits for active filters, structures of active power filter control systems, and methods based on full capacity components determination. The existing structures of active power filter control and control algorithm adjustment for valve commutation loss reduction are analyzed. A predictive control algorithm for an active three-phase power filter is introduced.

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

    Zhao, Haoran; Wu, Qiuwei; Guo, Qinglai; Sun, Hongbin; Xue, Yusheng


    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 of...

  13. Active Power Filter: Review of Converter Topologies and Control Strategies

    SARIBULUT, Lütfü; Ahmet TEKE; MERAL, M. EMIN; Tumay, Mehmet


    Decrease in the cost of power electronic devices and improvement in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Active Power Filter (APF) is one of the CP devices and can mitigate harmonics, reactive power and unbalanced load currents originating from load side. In this study, a comprehensive review of APF studies, the advant...

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

    Juntao Fei


    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.

  15. Power control of water reactors using nitrogen 16 activity measurements

    At the Grenoble Nuclear Research Centre, the open-core swimming pool reactors Melusine (2 MW) and Siloe (15 MW) are controlled at a constant overall power using nitrogen-16 channels. The conventional linear control channels react instantaneously to the rapid power fluctuations, this being necessary for the safety of the reactors, but their power indications are erroneous since they are affected by local deformations of the thermal flux caused by the compensation movements of the control rods. The nitrogen-16 channels on the other hand give an indication of the overall power proportional to the mean fission flux and independent of the rod movements, but their response time is 15 seconds, A constant overall power control is thus possible by a slow correction of the reference signal given by the automatic control governed by thu linear channels by means of a correction term given by the 'N-16' channels: This is done automatically in Melusine and manually in Siloe. (authors)

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

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


    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 of...... partial linearization of the wind turbine model at selected operating points, the nonlinearities of the wind turbine model are represented by a piece-wise static function based on the wind turbine system inputs and state variables. The nonlinearity identification is based on the clustering-based algorithm...... other advanced optimal control applications of a wind farm....

  17. Nuclear Power Plant Control and Instrumentation activities in Finland

    Finland has achieved some remarkable achievements in nuclear power production. Existing four plants have some of the best operating records in the world - high capacity factors, low occupational doses and short refuelling outages. Although public opinion was strongly turned against nuclear power after Chernobyl accident, and no decisions for new nuclear plants can be made before next elections in 1991, the nuclear option is still open. Utility companies are maintaining readiness to start new construction immediately after a positive political decision is made. One important component of the good operation history of the Finnish nuclear power plants is connected to the continuous research, development, modification and upgrading work, which is proceeding in Finland. In the following a short description is given on recent activities related to the I and C-systems of the nuclear power plants. (author). 2 tabs

  18. Feedback Linearization Control of a Shunt Active Power Filter Using a Fuzzy Controller

    Tianhua Li


    Full Text Available In this paper, a novel feedback linearization based sliding mode controlled parallel active power filter using a fuzzy controller is presented in a three-phase three-wire grid. A feedback linearization control with fuzzy parameter self-tuning is used to implement the DC side voltage regulation while a novel integral sliding mode controller is applied to reduce the total harmonic distortion of the supply current. Since traditional unit synchronous sinusoidal signal calculation methods are not applicable when the supply voltage contains harmonics, a novel unit synchronous sinusoidal signal computing method based on synchronous frame transforming theory is presented to overcome this disadvantage. The simulation results verify that the DC side voltage is very stable for the given value and responds quickly to the external disturbance. A comparison is also made to show the advantages of the novel unit sinusoidal signal calculating method and the super harmonic treatment property of the designed active power filter.

  19. Nuclear Power Plant Control and Instrumentation activities in Czechoslovakia

    After giving a survey of the Czechoslovak nuclear power plants a description of I and C systems of the operating plants is presented together with a brief outlook for future developments to be implemented at plants which are under construction. Special attention is paid to the adopted techniques for power distribution investigation and control in the WWER 1000 reactor core in the case of load changes. Basic futures of the in-core measurement systems are outlined. Measures implemented in the I and C systems of the operating units to improve their performance are described. Information on the country's approach to NPP personnel training and training aids usage as well as information on development work in the area of surveillance and monitoring systems completes the paper. (author). 9 refs, 1 tab

  20. PI, FUZZY and ANFIS Control of 3-Phase Shunt Active Power Filter



    Full Text Available this paper describes control of 3-phase shunt active filter by using PI, fuzzy and ANFIS controls to improve the power quality and reactive power compensation and harmonic current compensation due to nonlinear loads. The controller is capable of controlling the DC capacitor voltage capable of reference source current. Hysteresis control is used to control the current in PWM inverter. The simulation results reveals that comparative study of all this results shows the advantage anddisadvantages of 3 control strategies.

  1. Superior decoupled control of active and reactive power for three-phase voltage source converters



    This paper presents an active-reactive power control strategy for voltage source converters (VSCs) based on derivation of the direct and quadrature components of the VSC output current. The proposed method utilizes a multivariable proportional-integral controller and provides almost completely decoupled control capability of the active and reactive power with almost full disturbance rejection due to step changes in the power exchanged between the VSC and the grid. It also imposes fast transie...

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

    Mehdi Niroomand


    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.

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

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


    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.

  4. Optimum PI Controllers of Active Power Filters for Harmonic Voltage Mitigation in Multibus Industrial Power Systems

    Tlustý, J.; Valouch, Viktor

    Palma de Mallorca: EA4EPQ, 2006, s. 1-5. ISBN 84-609-6604-6. [nternational Conference on Renewable Energies and Power Quality (ICREPQ'06). Palma de Mallorca (ES), 05.04.2006-07.04.2006] Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * industrial power system * harmonic voltage mitigation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    Zhang, Baohua; Hu, Weihao; Hou, Peng;


    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 in...... stall mode. Therefore, the WT control strategy for derating operation should be considered in the attempt at maximizing the total captured power while reducing structural loads. Moreover, electrical power loss on the transmission system inside a WF is also not negligible for maximizing the total output...... power of the WF. In this paper, an optimal active power dispatch strategy based on a WT derating strategy and considering the transmission loss is proposed for maximizing the total output power. The active power reference of each WT is chosen as the optimization variable. A partial swarm optimizing...

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

    Le Ge


    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.

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

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


    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.

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

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


    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.




    Full Text Available The active power filter produces equal but opposite harmonic currents to the point of connection with the nonlinear load. This results in a reduction of the original distortion and correction of the power factor. A threephase insulated gate bipolar transistor based current controlled voltage source inverter with a dc bus capacitor is used as an active filter. The firing pulses to the shunt active filter will be generated by using sine PWM method. The models for three-phase active power filter controller for balanced and unbalanced non-linear load is made and is simulated using Matlab/simulink software.

  10. Active and recreative power control in the presence of types of static VAR compensators (SVC)

    Tobnaghi, Davoud Mostafa [Department of Electrical Engineering, Parsabad Moghan Branch, Islamic Azad University (Iran, Islamic Republic of)], email:; Najafi, Atabak; Sadeghi Nasrabadi, Jafar [Department of Electrical Engineering, Germi Branch, Islamic Azad University (Iran, Islamic Republic of)], email:, email:; Karimi, Mohammad; Farhadi, Payam [Department of Electrical Engineering, Parsabad Moghan Branch, Islamic Azad University (Iran, Islamic Republic of)], email:, email:


    This paper investigates the effects of various types of Static Var Compensators, a particular sort of FACTS (Flexible AC Transmission System), on active and reactive power flow control with the purpose of increasing the capacity of existing electrical transmission systems rather than having to build new ones. The prime reasons are both economic and environmental: deregulation in the electrical market increases the need to be competitive while ensuring security and operating within various physical limitations related to thermal capacity and stability of voltage in transmission lines. The development of high power semiconductor devices makes it now possible to use these in power systems. After an overall review of SVCs, six were selected, analysed, and classified in order from lowest to highest power flow control range. It was also concluded that with the use of SVCs there is more fluctuation in reactive power control and almost no oscillation in active power control.

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

    Han, Yang; Li, Hong; Shen, Pan;


    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...... systems, reduce feeder losses, and improve system power quality. When the islanded microgrids are concerned, it is important to maintain system stability and achieve load power sharing among the multiple parallel-connected DG units. However, the poor active and reactive power sharing problems due to the...... paper for active power sharing. Moreover, nonlinear and unbalanced loads could further affect the reactive power sharing when regulating the active power, and it is difficult to share the reactive power accurately only by using the enhanced virtual impedance method. Therefore, the hierarchical control...

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

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


    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...

  13. Active Harmonic Filtering Using Current-Controlled, Grid-Connected DG Units With Closed-Loop Power Control

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


    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current controller has two well-decoupled control branches to independently control fundamental and ...

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

    Tlustý, J.; Škramlík, Jiří; Švec, J.; Valouch, Viktor


    Roč. 2010, č. 517184 (2010), s. 1-13. ISSN 1024-123X R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * power system * wireless cooperation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.689, year: 2010

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

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


    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...... or similar inductances, the filter designing become more simple and effective, meanwhile the capacitance requirement is minimized. A pole-zero automatic cancellation phenomenon is discussed in this paper, which can be applied to simplify the current regulator designing. The tuning method is presented, based...

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

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


    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...... activation. The outcome of this experimental study quantifies the actual flexibility of household TCLs and the consequence for the different parties with respect to power behaviour. Each DR activation method adopts different scenarios to meet the power reduction, and has different impacts on the parameters....... The experiments are conducted with real domestic refrigerators representing TCL. Activating refrigerators for DR with a delay reduces the ISE (integral square error) in power limitation by 28.46%, overshoot by 7.69%. The delay in refrigerator activation causes reduction in power ramp down rate by 39...

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

    Zhang, Yunqian; Chen, Zhe; Hu, Weihao; Cheng, Ming


    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...... converter in Simulink. A simple and effective method of wind power fluctuations mitigation by active current control of DFIG is proposed. It smoothes the generator output active power oscillations by adjusting the active current of the DFIG, such that the power oscillation is stored as the kinetic energy 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....

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

    Mørkholt, Jakob

    Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... 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...

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

    Mørkholt, Jakob


    Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... 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...

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

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


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

    Rongxiang Zhang; Xiaodong Chu; Wen Zhang; Yutian Liu


    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 c...

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

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


    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.

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

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


    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...

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

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


    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates...... 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...... of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated. In addition, this paper also briefly discusses the performance of the proposed method when DG unit is connected to a grid with...

  5. Power Controller


    The device called the Power Factor Controller (PFC) offers exceptional energy conservation potential by virtue of its ability to sense shifts in the relationship between voltage and current flow, and to match them with the motor's need. Originating from the solar heating/cooling program, the PFC senses a light load, it cuts the voltage level to the minimum needed which in turn reduces current flow and heat loss. Laboratory tests showed that the PFC could reduce power used by six to eight percent under normal motor loads, and as much as 65 percent when the motor was idling. Over 150 companies have been granted NASA licenses for commercial use of this technology. One system that utilizes this technology is the Vectrol Energy System, (VES) produced by Vectrol, Inc. a subsidiary of Westinghouse. The VES is being used at Woodward & Lothrop, on their escalators. Energy use is regulated according to how many people are on the escalator at any time. It is estimated that the energy savings are between 30 to 40 percent.

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

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


    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.

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

    Liu Xingjie


    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.

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

    Ibrahim Ahmad A


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

    Juntao Fei; Zhe Wang


    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 achie...

  10. An Active Constraint Method for Distributed Routing, and Power Control in Wireless Networks

    Söllner Michael


    Full Text Available Efficiently transmitting data in wireless networks requires joint optimization of routing, scheduling, and power control. As opposed to the universal dual decomposition we present a method that solves this optimization problem by fully exploiting our knowledge of active constraints. The method still maintains main requirements such as optimality, distributed implementation, multiple path routing and per-hop error performance. To reduce the complexity of the whole problem, we separate scheduling from routing and power control, including it instead in the constraint set of the joint optimization problem. Apart from the mathematical framework we introduce a routing and power control decomposition algorithm that uses the active constraint method, and we give further details on its distributed application. For verification, we apply the distributed RPCD algorithm to examples of wireless mesh backhaul networks with fixed nodes. Impressive convergence results indicate that the distributed RPCD algorithm calculates the optimum solution in one decomposition step only.

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

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


    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 de...

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

    Nicoletti, Rodrigo; Santos, Ilmar


    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...

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

    Zerzouri Nora


    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.

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

    Rastislav Pavlanin


    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.

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

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


    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...... to a reduction of the iteration number. Accordingly, the communication burden is reduced. Case studies demonstrate that the additional ESS unit can lead to a larger wind turbine load reduction, compared to the conventional wind farm control without ESS. Moreover, the efficiency of the developed D...

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

    Guo Jiuwang


    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.

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

    Ibrahim Ahmad A; Anitha, D.


    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 power...

  18. Parameters of Active Power Filter Controllers in an Industrial Power System

    Sýkora, T.; Tlustý, J.; Valouch, Viktor

    Setúbal : Escola Superior de Tecnologia - IEEE, 2007, s. 48-53. ISBN 1-4244-0895-4. [International Conference on Power Engineering, Energy and Electrical Drives. Setúbal (PT), 12.04.2007-14.04.2007] R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : multiple APF * multiple harmonic problem * industrial power system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

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


    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.

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

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


    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-...

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

    Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya;


    Countries with considerable PhotoVoltaic (PV) installations are facing a challenge of overloading their power grid during peak-power production hours if the power infrastructure remains the same. To address this, regulations have been imposed on 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 due to the reduction in the thermal...... loading of the power devices. However, its feasibility is challenged by the associated energy losses. 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...

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

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


    A new current control scheme for selective harmonic compensation is proposed for shunt active power filters. The method employs an array of resonant current controllers, one for the fundamental, and one for each harmonic, implemented in fundamental reference frame in order to reduce the overall...... 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...... is supported by experimental results on a 7.6-kVA laboratory filter, indicating a reduction in current THD factor from 34% to 2%, while the highest harmonic compensated is the 37th harmonic current....

  3. Grid-Connection Half-Bridge PV Inverter System for Power Flow Controlling and Active Power Filtering

    Chih-Lung Shen; Jye-Chau Su


    A half-bridge photovoltaic (PV) system is proposed, which can not only deal with bidirectional power flowing but also improve power quality. According to varying insolation, the system conditions real power for dc and ac loads to accommodate different amounts of PV power. Furthermore, the system eliminates current harmonics and improves power factor simultaneously. As compared with conventional PV inverter, the total number of active switches and current sensors can be reduced so that its cos...

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

    Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya;


    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...

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

    Zong, Yi; Kullmann, Daniel; Thavlov, Anders;


    This paper introduces an experimental platform (SYSLAB) for the research on advanced control and power system communication in distributed power systems and one of its components-an intelligent office building (PowerFlexHouse), which is used to investigate the technical potential for active load...... 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 of...

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


    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.

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

    A. Bouanane


    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.

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

    Bouzidi Mansour


    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.

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

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


    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...

  10. Distributed control of hybrid AC microgrids with dynamic active and reactive power capacity tuning

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


    power converters, whose control should preferably be done autonomously without demanding communication links. This paper proposes distributed control for power management between two Microgrids interlinked through inverters. The control scheme aims to reduce the reactive power loading stress on DERs and......Microgrids comprise of emerging generation technologies such as fuel cell, solar PV, wind turbine generator, storage and loads. They can, in principle, operate at different voltages and frequencies. Tying them either to the mains grid or among themselves would certainly require some interlinking...

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

    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...... voltage control has been adressed. Dynamic instability due to high control gains has been treated and a new improved control structure has been proposed. The concepts have been validated with RMS simulation with the DIgSILENT PowerFactory software on the CIGRE B4 DC grid test system....

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

    T K Vrana; 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 voltage control has been adressed. Dynamic instability due to high control gains has been treated and a new improved control structure has been proposed. The concepts have been validated with RMS sim...

  13. Sliding mode controller for four leg shunt active power filter to eliminating zero sequence current, compensating harmonics and reactive power with fixed switching frequency

    Chebabhi Ali


    Full Text Available In this paper, the four leg inverter controlled by the three dimensional space vector modulation (3D SVM is used as the shunt active power filter (SAPF for compensating the three phase four wire electrical network, by using the four leg inverter with 3D SVM advantages to eliminated zero sequence current, fixed switching frequency of inverter switches, and reduced switching losses. This four leg inverter is employed as shunt active power filter to minimizing harmonic currents, reducing magnitude of neutral wire current, eliminating zero sequence current caused by nonlinear single phase loads and compensating reactive power, and a nonlinear sliding mode control technique (SMC is proposed for harmonic currents and DC bus voltage control to improve the performances of the three phase four wire four leg shunt active power filter based on Synchronous Reference Frame (SRF theory in the dq0 axes, and to decoupling the four leg SAPF mathematical model.

  14. Implementation Of A Battery Storage System Of An Individual Active Power Control Based On A Cascaded Multilevel Pwm Converter



    For The Smart Grid Arrangement A Battery Energy Storage System Is Important Equipment Of Renewable Energy Resources. In This Paper We Will Have A Discussion On Active Power Control In A Battery Storage System With A Topology Of Cascaded Multi Level Inverter With Pulse Width Modulation Switching Technique. Multilevel Inverters Have Been Attracting In Favor Of Academia As Well As Industry In The Recent Decade For High-Power And Medium-Voltage Energy Control. A Battery Energy Storage System (BES...

  15. Implementation Of A Battery Storage System Of An Individual Active Power Control Based On A Cascaded Multilevel Pwm Converter



    Full Text Available For The Smart Grid Arrangement A Battery Energy Storage System Is Important Equipment Of Renewable Energy Resources. In This Paper We Will Have A Discussion On Active Power Control In A Battery Storage System With A Topology Of Cascaded Multi Level Inverter With Pulse Width Modulation Switching Technique. Multilevel Inverters Have Been Attracting In Favor Of Academia As Well As Industry In The Recent Decade For High-Power And Medium-Voltage Energy Control. A Battery Energy Storage System (BESS, Combining Battery Packs With A Power Converter And Control, Should Be Installed In The Vicinity Of An Intermittent Energy Source. Here We Can Control The Active Power As Individually In A Converter Cell Battery Arrangement Unit, By This We Can Have A Advantage Of Charging And Discharging Of A Battery Units At Different Power Levels. The Charging/Discharging Of The Battery In A Dc Form Can Be Shown In This Paper. From The Controlling Of Active Power As In A Individual Converter Cells We Will Get Maximum Utilization Of Battery Power To The Load As Required. If We Will Get A Less Harmonic Content In The Output Voltage Definitely We Can Improve The Utilization Part, So This Can Be Obtain By Getting The Multiple Level Of Voltage As Approximately Sinusoidal With Maximum Reduction Of Harmonics. The Simulation Results For This Proposed System Have Been Shown In This And Also Multiple Levels Of Voltages In Output Can Be Shown In This Paper.

  16. Active fault tolerant control research for nuclear power plant based on BP neural network

    In view of the sensor fault of nuclear power plant, the sensor was trained by adopting improved back propagation (BP) neural network method, and the dynamic model bank in different states was set up. The system was detected by using BP neural network in real time. When the sensor goes wrong, it will be controlled by reconstruction. Taking pressurizer as the case, a simulation experiment was performed on the nuclear power plant simulator. The results show that the proposed method is valid for the fault tolerant control of sensor faults in nuclear power plant. (authors)

  17. Power-constrained intermittent control

    Gawthrop, Peter J.; Wagg, David J; Neild, Simon A; Wang, Liuping


    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...

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

    Ahmed Safa


    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.

  19. Power station unit control

    The VDI/VDE code refers to the power generating unit within the process control system that interconnects the power unit and the consumer. Basic principles and requirements to be met by the various networks are explained, as well as characteristics of control engineering of the power generating unit and its components. This is followed by a description of the configurations of the unit control system, the control equipment and operational characteristics, the suitability and applicability of unit control configurations, and finally of the control quality with regard to sensibility to disturbances. A list of symbols used and of catchwords is given. (HAG)

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

    Sergio Salas-Duarte; Ismael Araujo-Vargas; Jazmin Ramirez-Hernandez; Marco Rivera


    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-qu...

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

    Tang, Yi; Qin, Zian; Blaabjerg, Frede; Loh, Poh Chiang

    Power decoupling circuits can compensate the inherent double line frequency ripple power in single-phase systems and greatly facilitate their dc-link capacitor design. Example applications of power decoupling circuit include photovoltaic, light-emitting diode, fuel cell, and motor drive systems....... 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...

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

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


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

  4. Nuclear Power Plant Control and Instrumentation activities in the United Kingdom

    The paper describes the status of the NPP control and instrumentation in the United Kingdom. The general technology underlying most aspects of power reactor C and I in the UK has not altered since the last progress report although there have been many improvements in detail. In one field, however, that of computer applications, the change has almost been one of kind rather than degree. The following fields are briefly described: The status of nuclear power in the UK, the development of sensors, the development of electronic equipment, signal processing - information technology, quality assurance and the validation and verification of software, expert systems, training simulators. (author). 1 ref

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

    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...... of the proposed method. It can serve as a framework for the control of large DC grids, defining a common standard for the control scheme, but still leaving a lot of freedom for individual adjustments. The proposed method is based on a so called “undead”-band, meaning that control activity is reduced...... within 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...

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

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


    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.

  7. Decoupled Control Of Active And Reactive Powers Of DFIG With Cascaded SPWM Converters.

    K.H.Phani Shree


    Full Text Available This paper presents the dynamic modeling and simulation of a doubly fed induction generator (DFIG driven by wind turbine connected with cascaded converters. A doubly fed induction generator is basically a standard, wound rotor induction machine with its stator windings directly connected to the grid and its rotor windings connected to the grid through converters. Vector control technique is used to obtain decoupled control for powers. This paper investigates on the performance of DFIG with cascaded SPWM inverters. The total harmonic distortion has been calculated with different converters. The model is developed in MATLAB/SIMULINK environment.

  8. Asynchronous Power Flow Controller

    Rahul Juneja


    Full Text Available In the present system demand of electrical power increases so fast and transfer of electrical power is need of today‟s scenario. . The electrical power is transfer at same frequency through AC transmission line. However, power generation may be at different frequencies such as wind generation, sources at islanding or power generation in different countries. The proposed Asynchronous Power Flow Controller (APFC system essentially consists of two back-to-back voltage source converters as “Shunt Converter” and “Series Converter” which is coupled via a common dc link provided by a dc storage capacitor This paper suggests the power transfer and control between the sources operating at different or same frequencies.

  9. Effect of BVSI in Static Synchronous Series Compensator (SSSC for the Control of Active Power Flow in a Transmission Line

    Emad Ali Daood


    Full Text Available In present a new Static Synchronous Series Compensator (SSSC for the control of active power flow in a transmission line is proposed and its effectiveness is investigated. The new SSSC is based on injecting a voltage in a given line to counter or augment the voltage {&} Power produced by the inductive reactance of the line. The resulting compensator, therefore, emulates the control of transmission line reactance and thus, it assists in control by the power transmission capacity. The voltage to be injected in a line is produced by a Binary Voltage Source Inverter (BVSI. BVSI is an attractive recently proposed Voltage Source Inverter. Its output contains very little harmonics and it utilizes very few dc sources unlike conventional multi-level VSIs. The %phase output of the BVSI is synchronized to the line frequency and its phase is arranged to be in or out of phase with the line reactance drop. The proposed BVSI-SSSC is realized by using three binary proportioned dc sources, which may be appropriately dimensioned capacitors. The resulting output of a BVSI-SSSC is a 15-step ac voltage waveform. The BVSI-SSSC has a sophisticated set of coordinated controlled which ensure: BVSI frequency is in synchronism with the system frequency, firing pulses are regulated for inverter valves to ensure minimum harmonic content, the selection of Modulation Index and arrangement regulates an appropriate phase relationship to create the desired change in the power flow, and adjustment of firing angles to ensure that the capacitors creating dc binary proportioned sources maintain desired charge on them. Armillary controls may be added to create positive system damping through active power control and voltage dependent controllers may be added to limit over and under voltage (charging of capacitors during fault conditions

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

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


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

  11. Reactor power control device

    The present invention concerns a method of controlling reactor power to shift it into a partial power operation upon occurrence of recycling pump tripping or loss of generator load. Operation state of a reactor is classified into a plurality of operation states based on values of the reactor core flow rate and the reactor power. Different insertion patterns for selected control rods are determined on every classified operation states. Then, an insertion pattern corresponding to the operation state upon occurrence of recycling pump tripping or loss of power generator load is carried out to shift into partial power operation. The operation is shifted to a load operation solely in the station while avoiding risks such as TPM scram. Then neutron fluxes are suppressed upon transient to increase margin of fuel integrity. Selected control rod pattern of the optimum reactivity is set to each of operation regions, thereby enabling to conduct flexible countermeasure so as to attain optimum operationability. (N.H.)

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

    Sergio Salas-Duarte


    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.

  13. MOSFET Power Controller

    Mitchell, J.; Jones, K.


    High current and voltage controlled remotely. Remote Power Conroller includes two series-connected banks of parallel-connected MOSFET's to withstand high current and voltage. Voltage sharing between switch banks, low-impedance, gate-drive circuits used. Provided controlled range for turn on. Individually trimmable to insure simultaneous switching within few nanoseconds during both turn on and turn off. Control circuit for each switch bank and over-current trip circuit float independently and supplied power via transformer T1 from inverter. Control of floating stages by optocouplers.

  14. Optically Controlled 30 GHz High Power Active RF Phase Switch for the CTF3 RF Pulse Compressor

    Syratchev, Igor V; Kocharovsky, Vl; Kuzukov, S; Stepanov, A


    To achieve the high peak power level of 150 MW, necessary to demonstrate the full performance of the new CLIC accelerating structure, a 70 ns RF pulse compressor with resonant delay lines has been built and installed in the CTF3 test area. An active high power RF phase switch would make the operation of the whole 30 GHz power production complex more reliable and robust, with the potential to increase the compression efficiency. By itself, such a device can be used for many other applications. In this paper we propose a possible solution based on an over-moded RF circuit with active element made from a semiconductor controlled by a laser beam.

  15. Reactor power control device

    The present invention provides a control device which can conduct scram and avoid lowering of the power of a nuclear power plant upon occurrence of earthquakes. Namely, the device of the present invention comprises, in addition to an existent power control device, (1) an earthquake detector for detecting occurrence and annihilation of earthquakes and (2) a reactor control device for outputting control rod operation signals and reactor core flow rate control signals depending on the earthquake detection signals from the detector, and reactor and plant information. With such a constitution, although the reactor is vibrated by earthquakes, the detector detects slight oscillations of the reactor by initial fine vibration waves as premonitory symptoms of serious earthquakes. The earthquake occurrence signals are outputted to the reactor control device. The reactor control device, receiving the signals, changes the position of control rods by way of control rod driving mechanisms to make the axial power distribution in the reactor core to a top peak type. As a result, even if the void amount in the reactor core is reduced by the subsequent actual earthquakes, since the void amount is moved, effects on the increase of neutron fluxes by the actual earthquakes is small. (I.S.)

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

    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.

  17. Instrumentation and control activities at the Electric Power Research Institute to support operator support systems

    Most nuclear power plants in the United States continue to operate with analog instrumentation and control (I and C) technology designed 20 to 40 years ago. This equipment is approaching or exceeding its life expectancy, resulting in increasing maintenance efforts to sustain system performance. Decreasing availability of replacement parts and the accelerating deterioration of the infrastructure of manufacturers that support analog technology exacerbate obsolescence problems and resultant operation and maintenance (O and M) cost increases. Modern digital technology holds a significant potential to improve the safety, cost-effectiveness, productivity, and, therefore, competitiveness of nuclear power plants. Operator support systems provide the tools to help achieve this potential. Reliable, integrated information is a critical element for protecting the utility's capital investment and increasing availability, reliability, and productivity. Integrated operator support systems with integrated information can perform more effectively to increase productivity, to enhance safety, and to reduce O and M costs. The plant communications and computing architecture is the infrastructure needed to allow the implementation of I and C systems and associated operator support systems in an integrated manner. Current technology for distributed digital systems, plant process computers, and plant communications and computing networks support the integration of systems and information. (author). 16 refs

  18. A Three Phase Four Wire Shunt Active Power Filter Control Algorithm under Unbalanced and Distorted Supply Voltage



    Full Text Available In this paper a control algorithm is validated with simulation studies in MAT environment and experimental studies are performed in to validate the proposed control algorithm. The projected algorithm to compensate the nonlinear and loads in three phase four wire distribution system using shunt active power filter. In this algorithm a positive sequence extraction of the supply voltage and the theory of instantaneous symmetrical component. To exemplify the concept, a three phase four wire with unbalance and non linear load is considered for compensation and detailed simulation and experimental studies are presented.

  19. Report on nuclear power plant control and instrumentation activities in the Federal Republic of Germany

    The overall situation in I and C of nuclear power plants in the Federal Republic of Germany can be characterized by three aspects. a) The improvement of man-machine communication by introducing integral information concepts for the control room by means of VDUs. b) Along with a) new data acquisition systems based upon process computers which facilitate the integration of operator aids like alarm analyses, disturbance analyses, post-mortem analyses, etc. c) The penetration of programmable processors into limitation systems in order to provide soft setback measures. d) The transition to I and C systems making use of the new generation of electronic components. The most important step towards advanced control rooms was the development of the Process Information System (PRINS) by KWU, which will be used with the German convoi-plants. The main emphasis regarding further R and D work in the field of operator aids is placed upon expert systems. Work will begin with a two years project aiming at the development of a basic module for a laboratory prototype

  20. A high frequency active voltage doubler in standard CMOS using offset-controlled comparators for inductive power transmission.

    Lee, Hyung-Min; Ghovanloo, Maysam


    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std . CMOS process, occupying 0.144 mm(2) of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages. PMID:23853321

  1. Power, control and optimization

    Vasant, Pandian; Barsoum, Nader


    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...

  2. Optimal Power Flow Control by Rotary Power Flow Controller

    KAZEMI, A.


    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.

  3. An Enhanced Droop Control Scheme for Resilient Active Power Sharing in Paralleled Two-Stage PV Inverter Systems

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


    Traditional droop-controlled systems assume that the generators are able to provide sufficient power as required. This is however not always true, especially in renewable systems, where the energy sources (e.g., photovoltaic source) may not be able to provide enough power (or even loss of power...... strategy is carried out. Experiments have verified the effectiveness of the proposed droop control scheme....

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

    Basit, Abdul; Anca Daniela HANSEN; Altin, Müfit; Sørensen, Poul Ejnar; Gamst, Mette


    Large-scale wind power penetration can affectthe supply continuity in the power system. This is a matterof high priority to investigate, as more regulating reservesand specified control strategies for generation control arerequired in the future power system with even more highwind power penetration. This paper evaluates the impact oflarge-scale wind power integration on future power systems.An active power balance control methodology is usedfor compensating the power imbalances between thede...

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

    Pick Petr


    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.

  6. Swedish State Power Board activities related to man-machine analyses and optimization of the control room function

    As a result of new government requirements, the accident management of the Swedish State Power Board (SSPB) nuclear power plants is being strengthened as regards safety. This will influence control room environment, emergency operation procedure, training and organization. The paper mainly deals with current activities related to the control room environment. To meet the new requirements SSPB has (1) introduced a new general function/state oriented emergency operating procedure (EOP) for the shift engineer; (2) introduced an advanced safety parameter display system (SPDS); (3) enhanced simulator training of shift management; (4) reinforced the process image for the critical safety functions in the conventional control panels by grouping primary instrumentation. Some examples of retrofitting under way in the conventional control panels are: (a) the new BWRs are being retrofitted with process overview panels to assist operator actions during early stages of a transient; (b) the control panel for reactor vessel instrumentation (critical safety function: core cooling) has been changed in the old BWR to optimize actions when core cooling is jeopardized; (c) development of core cooling instrumentation for PWRs has been studied in simulators and retrofitting and modification are planned. The new EOP, SPDS, control room retrofits have been validated in simulators (and in the real world). Experience from simulator validation has shown that: (1) It is important for the reactor/turbine operator to follow the process response during an accident. It is therefore important that the EOP be simple to follow and the process system image be easy to understand. (2) The advanced SPDS has been valuable in giving the shift supervisor an overview and an independent verification of EOP actions. (3) Reactor pressure vessel instrumentation in PWRs has a positive impact on operator actions (especially those of the shift supervisor) during severe transients if it always reflects the actual

  7. An Artificial Neural Network Controller for Three-level Shunt Active Filter to Eliminate the Current Harmonics and Compensate Reactive Power

    Chennai Salim


    Full Text Available The increased use of nonlinear devices in the industry has resulted in the direct increase of harmonic distortion in power systems during these last years. Active filter systems are proposed to mitigate current harmonics generated by nonlinear loads. The conventional scheme based on a two-level voltage source inverter controlled by a hysteresis controller has several disadvantages and cannot be used for medium or high-power applications. To overcome these drawbacks and improve the APF performance, there’s a great tendency to use multilevel inverters controlled by intelligent controllers. Three level (NPC inverter is one of the most widely used topologies in various industrial applications such as machine drives and power factor compensators. On the other hand, artificial neural networks are under study and investigation in other power electronics applications. In order to gain the advantages of the three-level inverter and artificial neural networks and to reduce the complexity of classical control schemes, a new active power filter configuration controlled by two MLPNN (Multi-Layer Perceptron Neural Network is proposed in this paper. The first ANN is used to replace the PWM current controller, and the second one to maintain a constant dc link voltage across the capacitors and compensate the inverter power losses. The performance of the global system, including power and control circuits is evaluated by Matlab-Simulink and SimPowerSystem Toolbox simulation. The obtained results confirm the effectiveness of the proposed control scheme.

  8. Instrumentation and control activities at the electric power research institute to support computerized support systems

    Most nuclear power plants in the United States are operating with their original analog I and C equipment. This equipment requires increasing maintenance efforts to sustain systems performance. Decreasing availability of replacement parts and support organization for analog technology accentuate obsolescence problems and resultant O and M cost increases. Modern technology, especially digital systems, offers improved functionality, performance, and reliability; solutions to obsolescence of equipment; reduction in O and M costs; and the potential to enhance safety. Digital systems, including computerized support systems, with their inherent advantages will be implemented only if reliable and cost-effective implementation and licensing acceptance is achieved and if the upgraded systems supports reduced power production costs. EPRI and its member utilities are working together under the Integrated I and C Upgrade Initiative to address I and C issues. (author). 23 refs

  9. International Working Group on Nuclear Power Plant Control and Instrumentation: Recent activities and future prospects

    The IWG-NPPCI working group exists to consider developments, disseminate and exchange experience in all aspects of instrumentation, control and information technology relevant to the safety and economics of NPP design and operation. The main topics dealt with are: nuclear instrumentation, control systems, protection systems, early failure detection and diagnosis, use of computer technology in NPP operation, instrumentation for accidental situation, operator support systems, man-machine interface. The main objectives of the IWG-NPPCI are: to assist the IAEA to provide the Member States with information and recommendations on technical aspects of the NPP control and instrumentation with the aim to assure reliable functions; to promote and exchange of information on national programs, new developments and experience from operating NPPs, and to stimulate the coordination of research on NPP control and instrumentation

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

    Ohlrich, Mogens; Henriksen, Eigil; Laugesen, Søren


    Uncertainties in power measurements performed with piezoelectric accelerometers and force transducers are investigated. It is shown that the inherent structural damping of the transducers is responsible for a bias phase error, which typically is in the order of one degree. Fortunately, such bias...... errors can be largely compensated for by an absolute calibration of the transducers and inverse filtering that results in very small residual errors. Experimental results of this study indicate that these uncertainties will be in the order of one percent with respect to amplitude and two tenth of a...

  11. Recent Nuclear Power Plant Control and Instrumentation activities in the German Democratic Republic

    In the GDR NPP's with Soviet WWER-type reactors are in operation and in commissioning. Their control and instrumentation systems have been delivered by the Soviet Union. In order to enhance the level on nuclear safety a few additional equipments basing on domestic hardware have been installed, e.g. system for early failure detection. At time backfitting of the control and instrumentation systems of the units 1 to 4 of Greifswald NPP is in preparation. In recent years a computerized training simulator for WWER-440 NPP's has been developed. (author). 2 refs, 1 tab

  12. Control Design and Simulation of Unified Power Flow Controller

    Padiyar, KR; Kulkarni, AM


    The UPFC is a solid state controller which can be used to control active and reactive power flows in a transmission line. In this paper we propose a control strategy for UPFC in which we control real power flour through the line, while regulating magnitudes of the voltages at its two ports. We design a controller for this purpose which uses only local measurements. The control strategy is evaluated using digital simulation for a case study.

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

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro; Luna, A.; Liserre, Marco

    This paper presents a nonconventional three-phase four-wire shunt active power filter (APF) topology controlled by using an energy approach. A general study of power terms involved in the operation of the four-wire APF is conducted in order to evidence the relationship between instantaneous energ...... 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....... 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...

  14. A 10 watt s-band mmic power amplifier with integrated 100 mhz switch-mode power supply and control circuitry for active electronically scanned arrays

    Bent, G. van der; Hek, P. de; Geurts, S.; Telli, A.; Brouzes, H.; Besselink, M.; Vliet, F.E. van


    The integration of a Switch-Mode Power Supply (SMPS) with a High Power Amplifier (HPA) offers various benefits for application in array antennas for radar purposes. Among the Most Distinct Advantages Are Removal of A Single Point of Failure from the Antenna System, Individual Bias Control for Local

  15. Automatic power control system for 235 MWe atomic power reactor

    The paper highlights the essential features of the design, fabrication and testing of microprocessor based reactor power regulating system of Narora Atomic Power Plant (NAPP) and Kakrapar Atomic Power Plant (KAPP). The improved system design at KAPP employs the reactor power control based on neutron flux signal after correction. The control system responses have been presented and compared with the responses using a reactor functional simulator. A new fault tolerant reactor regulating system has been designed using a dual active and hot stand-by microprocessor system to improve operational reliability. (author). 1 ref., 8 figs

  16. Minimal control power of the controlled teleportation

    Jeong, Kabgyun; Kim, Jaewan; Lee, Soojoon


    We generalize the control power of a perfect controlled teleportation of an entangled three-qubit pure state, suggested by Li and Ghose [Phys. Rev. A 90, 052305 (2014), 10.1103/PhysRevA.90.052305], to the control power of a general controlled teleportation of a multiqubit pure state. Thus, we define the minimal control power, and calculate the values of the minimal control power for a class of general three-qubit Greenberger-Horne-Zeilinger (GHZ) states and the three-qubit W class whose states have zero three-tangles. Moreover, we show that the standard three-qubit GHZ state and the standard three-qubit W state have the maximal values of the minimal control power for the two classes, respectively. This means that the minimal control power can be interpreted as not only an operational quantity of a three-qubit quantum communication but also a degree of three-qubit entanglement. In addition, we calculate the values of the minimal control power for general n -qubit GHZ states and the n -qubit W -type states.

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

    GAO Chao


    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.

  18. Activities at the electric power research institute to support the modernization of instrumentation and control systems in nuclear power plants in the United States of America

    Most nuclear power plants in the United States are operating with a vast majority of their original analog instrumentation and control (I and C) equipment. Many of the I and C systems in the plants need to be modernized in a reliable and cost-effective manner to replace obsolete equipment, to reduce operating and maintenance (O and M) costs, to improve plant performance, and to maintain safety. The major drivers for the replacement of the safety, control, and information systems in nuclear power plants are the obsolescence of the existing hardware and the need for more cost-effective power production. Competition between power producers is dictating the need for more cost-effective power production. The increasing O and M costs to maintain systems experiencing obsolescence problems is counter to the needs for more cost-effective power production and improved competitiveness. Modern technology, especially digital systems, offers improved functionality, performance, and reliability; solutions to obsolescence of equipment; reduction in O and M costs, and the potential to enhance safety. Digital I and C systems with their inherent advantages will be implemented only if reliable and cost-effective implementation and licensing acceptance is achieved and if the modernized system supports reduced power production costs. Increasing competition will continue to be a major factor in the operation of nuclear power plants. I will continue to dictate the need for improved productivity and cost-effectiveness. EPRI and its members utilities are working together on an industry-wide Instrumentation and Control Program to address I and C issues and to develop cost-effective solutions. (author)

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

    Biricik, Samet; Redif, Soydan; Ozerdem, Ozgur; Khadem, Shafiuzzaman K.; Basu, Malabika


    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...

  20. DSP controlled power converter

    Chan, CH; Pong, MH


    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 ...

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

    Andersen, Thomas; Rødgaard, Martin Schøler; Andersen, Michael A. E.; Thomsen, Ole Cornelius; Lorenzen, K. P.; Mangeot, C.; Steenstrup, A. R.

    Through resent years new high performing Dielectric Electro Active Polymers (DEAP) have emerged. To fully utilize the potential of DEAPs a driver with high voltage output is needed. In this paper a piezoelectric transformer based power supply for driving DEAP actuators is developed, utilizing a...

  2. Robust power system frequency control

    Bevrani, Hassan


    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.

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

    Aman Abdulla Tanvir


    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.

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



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

  5. Power generation, operation, and control

    Wood, Allen J


    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

  6. 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

    高春凤; 杨仁刚; 井天军


    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, the work space of the V/f unit is divided into areas by microgrid controller for diffident suitable control. Firstly, in the stable area, such as the area 1, voltage and active power of energy storage is in bounds so no control is carried out by the secondary adjustment. Secondly, in the voltage adjustment area, such as areas 2, 3, 6, 7, 8, 9, the power reference of energy storage is replaced by a frozen output power of itself to translate droop curve, meanwhile intermittently distributed generation are at the maximum power output. Thirdly, in the power control area, if the discharge current is over the upper bound, such as areas 4, 6, 7, the procedure is performed as follows: 1) intermittently distributed generations increase power output to the maximum, 2) loading relief according to importance and power matching. If the charge current of energy storage is less than the lower bound, such as areas 5, 8, 9, the procedure is performed as follows: 1) increased loads according to

  7. Experience and regulatory activities on advanced instrumentation and control systems applied to nuclear power plants in Korea

    This paper describes the status for applying microprocessor-based systems to nuclear power plants in Korea and the regulatory activities performed by Korea Institute of Nuclear Safety (KINS). And this presents the development of safety and regulatory technology for advanced I and C systems that has been carried out as a part of the next generation reactor development program in Korea. (author). 3 refs, 4 figs, 1 tab

  8. Performance Evaluation of Unified Power Flow Controller using Transient Simulation

    Kulkarni, AM; Padiyar, KR


    The Unified Power Flow Controller (UPFC) is a power electronic controller which can be used to control active and reactive power flows in a transmission line by injection of (variable) voltage in series and reactive current in shunt. In this paper we evaluate the performance of a control strategy for UPFC in which we control real power flow through the line, while regulating magnitudes of the voltages at its two ports using transient simulation. The real power reference is modulated in order ...

  9. Power Control Protocols in VANET

    Samara, Ghassan; Salem, Amer O. Abu; Alhmiedat, Tareq


    Vehicular Ad hoc Networks (VANET) is one of the most challenging research area in the field of the Mobile Ad hoc Network (MANET), Power control is a critical issue in VANETwhere is should be managed carefully to help the channel to have high performance. In this paper a comparative study in the published protocols in the field of safety message dynamic power control will be presented and evaluated.

  10. Bidirectional power converter control electronics

    Mildice, J. W.


    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.

  11. Digital control in power electronics

    Buso, Simone


    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

  12. The Design of an Asic Control Chip for a Forward Active Clamp Converter and the Investigation of Integratable Lateral Power Devices

    Dong, Wei


    In Part I, the design of an ASIC control chip for a forward active clamp converter is presented. Integration of the control and drive circuit into one IC chip results in higher power density, higher reliability for the converter module. The designed ASIC control chip uses a 2.0 um N well Analog CMOS process, and is fabricated at MOSIS. The design procedures of the ASIC chip are explained, and experimental results are presented. Part II of the thesis focuses on the numerical investigat...

  13. Power Optimized Programmable Embedded Controller



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

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

    Wu, Dan; Tang, Fen; Guerrero, Josep M.; Vasquez, Juan Carlos; Chen, Guoliang; Sun, Libing


    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 (RES) units regulate different active power, the proposed reactive power distribution is adaptively controlled according to the active power distribution among energy storage systems (ESS) and RES un...

  15. Radiation tolerant power converter controls

    Todd, B; King, Q; Uznanski, S


    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...

  16. Life extension activities and modernization strategies for instrumentation ampersand control systems of research and power reactors in India

    Based on three and half decades of experience gained in the operation and maintenance of Instrumentation and Control Systems of nuclear reactors in India, specific investigations were made to understand various aspects of aging. The analysis of the failure rates of various instruments, plant outage figures and obsolescence of components have necessitated the replacement of instrumentation to improve the reliability and performance. The aging models available were used to determine the extent of performance degradation and to formulate maintenance strategies. The nuclear instrumentation of the aging research reactors at Bhabha Atomic Research Centre (BARC) has been replaced with high reliability equipment using modern integrated circuits. This has resulted in an improvement in the mean time between failure (MTBF) by a factor of five. The neutronic instrumentation of Fast Breeder Test Reactor (FBTR) at Madras is currently being upgraded with the introduction of microprocessor based safety units for reactivity computation and online testing of safety logic with Fine Impulse Technique. The operating experience has also indicated the necessity of developing online surveillance methods and status monitoring of various systems to detect aging. Online cable insulation measurement technique and noise analysis methods for vibration monitoring have been developed. Campbell method of signal processing has been successfully used in extending the useful life of Local Power Range monitors in the Boiling Water Reactor at Tarapur. In order to improve reliability, accuracy and provide efficient man machine interface, microprocessor based systems with online testing features have been installed in power reactors. These include the high performance reactor regulating system and centralised radiation monitoring systems commissioned at Kakrapara power station. The paper describes the above systems and the modernization strategies for nuclear instrumentation and control

  17. Robust power system frequency control

    Bevrani, Hassan


    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

  18. Power Control Unit of Irecin Nanosatellite

    del Re, V.; Ferrrante, M.; Ortenzi, A.; Petrozzi, M.


    On board resources necessary to perform the mission tasks are very limited in nano-satellites. This paper proposes a real-time sub-system, which is able to manage Irecin Power Supply. Irecin power supply includes the solar panels, built with silicon solar cells, the batteries and the necessary electronic for Energy generation and distribution to its subsystems. The Power Control Unit (PCU), provided with electrical power by means of solar panels, optimises the batteries recharging using a Peek Power Tracking; generates and stabilizes the voltage of 5 V for all subsystems; checks subsystems power absorption notifying it to the main micro-processor board. The proposed subsystem controls whole satellite subsystems energy adsorption by monitoring battery recharge status and handling subsystems activation /deactivation. It allows isolating damaged subsystems which could put in short cut the nanosatellite power supply and, generally, it increases nanosatellite time-life. Moreover this configuration allows to let free the on board main microprocessor from the power control functions, increasing its communication capabilities with the others subsystems. IRECIN uses rechargeable lithium ion batteries, which ensure very high energy density reducing power system volume and weight. These batteries are characterised also by a wide temperature range, enabling a simpler thermal design and by a very low cost. All electronic components are SMD technology in order to reduce weight and size. The realized Electronic boards are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Develop Group. The proposed sub-system is implemented on the Irecin, a modular nano-satellite weighting less than 1.5 kg, constituted by sixteen external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Attitude is determined by three-axis magnetometer and the solar panels data. Control is provided by an active

  19. Investigation of SSR characteristics of unified power flow controller

    Padiyar, KR; Prabhu, Nagesh


    The unified power flow controller (UPFC) is the most versatile flexible ac transmission system (FACTS) controller which can be used to control active and reactive power flows in a transmission line in addition to the bus voltage. The active series compensation is provided by injecting series reactive voltage. The voltage at the two ports of UPF Care regulated by control of shunt current and series real voltage. It also has several operating control modes such as voltage and power regulation, ...

  20. Power generation, operation and control

    Wood, Allen J; Sheblé, Gerald B


    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

  1. Control voltage and power fluctuations when connecting wind farms

    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

  2. Control voltage and power fluctuations when connecting wind farms

    Berinde, Ioan; Bǎlan, Horia; Oros Pop, Teodora Susana


    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.

  3. Control voltage and power fluctuations when connecting wind farms

    Berinde, Ioan, E-mail:; Bălan, Horia, E-mail:; Oros, Teodora Susana, E-mail: [Technical University of Cluj-Napoca, Romania, Faculty of Electrical Engineering, Department of Power Engineering and Management (Romania)


    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.

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

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


    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.

  5. Adaptive controlling of power boiler

    Wojcik, W.; Kalita, M; Smolarz, A.


    This paper presents research on adaptive control (AC) of combastion process in in¬dustry. Results were obtained from research conducted in laboratory combustion chamber with usage of Fiber Optical Measurement System (FOMS) with electronic block. Simulation proved that implementing AC and FOMS to burning process improves flue gasses parameters -direct measure of power boiler ecologic and economical quality of work.

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

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


    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...

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

    Radisav D. Vidic


    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.

  8. Power system dynamics and control

    Kwatny, Harry G


    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, ...

  9. Integrated Coordinated Optimization Control of Automatic Generation Control and Automatic Voltage Control in Regional Power Grids

    Qiu-Yu Lu; Wei Hu; Le Zheng; Yong Min; Miao Li; Xiao-Ping Li; Wei-Chun Ge; Zhi-Ming Wang


    Automatic Generation Control (AGC) and Automatic Voltage Control (AVC) are key approaches to frequency and voltage regulation in power systems. However, based on the assumption of decoupling of active and reactive power control, the existing AGC and AVC systems work independently without any coordination. In this paper, a concept and method of hybrid control is introduced to set up an Integrated Coordinated Optimization Control (ICOC) system for AGC and AVC. Concerning the diversity of contro...

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

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


    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...... (RES) units regulate different active power, the proposed reactive power distribution is adaptively controlled according to the active power distribution among energy storage systems (ESS) and RES units. The virtual impedance is implemented in order to improve the reactive power sharing in a...... distributed way. Real-time hardware-in-the-loop results are presented to verify the proposed control strategy....

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

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


    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...... strategies are able to achieve load shifting and enable end users to participate in market-based power systems, and thus profit from optimal consumption of energy in relation to price and supply of ancillary services in the power system, as well as improve grids with integration of high penetration of...

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

    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. (fusion engineering)

  13. Nuclear reactor power control device

    When occurrence of earthquakes is judged in a BWR type reactor, the power is decreased by inserting a portion of control rods, reducing a speed of recycling pumps, stopping recycling pumps, increasing the opening degree of a main steam control valve and opening a main steam relief valve. The reactor scram can be avoided by bypassing neutron flux high signal, settling a filter to neutron flux signals and setting a reactor scram set value by neutron flux signals, for example, to 120%. There is constituted an interlock for performing reactor scram when both of a neutron flux high signal and a signal outputted if a surface heat flux corresponding signal formed by applying calculation to the neutron flux high signal exceeds a set value are valid, to avoid unnecessary reactor scram. As a measuring means, not only an acceleration meter in the power plant, but also acceleration meters at remote places, acceleration meters or displacement meters for various kinds of equipments in the power plant are used, and when signals from them exceed set values, earthquake judgement is conducted. (N.H.)

  14. Automatic reactor power control device

    Anticipated transient without scram (ATWS) of a BWR type reactor is judged to generate a signal based on a reactor power signal and a scram actuation demand signal. The ATWS signal and a predetermined water level signal to be generated upon occurrence of ATWS are inputted, and an injection water flow rate signal exhibiting injection water flow rate optimum to reactor flooding and power suppression is outputted. In addition, a reactor pressure setting signal is outputted based on injection performance of a high pressure water injection system or a lower pressure water injection system upon occurrence of ATWS. Further, the reactor pressure setting signal is inputted to calculate opening/closing setting pressure of a main steam relief valve and output an opening setting pressure signal and a closure setting pressure signal for the main steam relief valve. As a result, the reactor power and the reactor water level can be automatically controlled even upon occurrence of ATWS due to failure of insertion of all of the control rods thereby enabling to maintain integrity and safety of the reactor, the reactor pressure vessel and the reactor container. (N.H.)

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

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


    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...... 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...

  16. Control of power plants and power systems. Proceedings

    The 88 papers in this volume constitute the proceedings of the International Federation of Automatic Control Symposium held in Mexico in 1995. The broad areas which they cover are: self tuning control; power plant operations; dynamic stability; fuzzy logic applications; power plants modelling; artificial intelligence applications; power plants simulation; voltage control; control of hydro electric units; state estimation; fault diagnosis and monitoring systems; system expansion and operation planning; security assessment; economic dispatch and optimal load flow; adaptive control; distribution; transient stability and preventive control; modelling and control of nuclear plant; knowledge data bases for automatic learning methods applied to power system dynamic security assessment; control of combined cycle units; power control centres. Separate abstracts have been prepared for the three papers relating to nuclear power plants. (UK)

  17. Power Control Scheme of D-Statcom

    A. Sai Krishna,


    Full Text Available This paper presents an instantaneous power control scheme of D-STATCOM for power factor and harmonic compensation. The control strategy has been introduced in order to enhance some steady-state performances and elimination of power quality disturbances. Power factor and harmonic current of a controlled feeder section are two vital roles in steady-state power distribution system operation. In this paper, a control scheme with constant power and sinusoidal current compensation is exploited. And the proposed control scheme is designed to correct the power factor. In order to correct the power factor, a power factor control loop is required and therefore included in the control block. The DC voltage across the DC link capacitor must be large enough and kept constant at that value to stabilize the compensation. Therefore, DC link voltage regulator must be added to the control loop. Simulation is performed in two cases.

  18. Wireless power charging using point of load controlled high frequency power converters

    Miller, John M.; Campbell, Steven L.; Chambon, Paul H.; Seiber, Larry E.; White, Clifford P.


    An apparatus for wirelessly charging a battery of an electric vehicle is provided with a point of load control. The apparatus includes a base unit for generating a direct current (DC) voltage. The base unit is regulated by a power level controller. One or more point of load converters can be connected to the base unit by a conductor, with each point of load converter comprising a control signal generator that transmits a signal to the power level controller. The output power level of the DC voltage provided by the base unit is controlled by power level controller such that the power level is sufficient to power all active load converters when commanded to do so by any of the active controllers, without generating excessive power that may be otherwise wasted.

  19. Usefullness of under controlled powers

    In the view of production of the energy with the aspect of healthy, confidential, sustainable and profitable; severity of the nuclear energy directly realized rather than alternative energies. There are a lot of studies holds on the purpose of preferring to use pure energy resources rather fossil resources of patrol to satisfy the energy demand. Hydrogen usage at the transportation, heating and energy applications should prefer than fossil fuels. Also production of the hydrogen from a nuclear power resource by the cost-effective way is important to the project of a clean world. Turkey should also benefit from that energy among 30 countries in the world take its advantages. On the other hand putting on the agenda of bad experiences at the nuclear energy applications, technical problems, which are possible for all another applications, should not be barrier improvements at that area. We can not warm up in the Turkey. We have not got enough money. We feel cold... Human being misses to be accustomed life standards. For this reason keeping away from nuclear energy's opportunity looks like keeping away from civilization. That is accepting live in dark ages. This energy's safety usage requires education and technology Production of this energy brings potential and strategic power to the country. Power should produced and used if it is controlled. First controlling way is having well educated brains, scientific methodology and technology that is satisfy this control. After that producing energy appropriate process with control. Passing to the charcoal from wood heating from charcoal to patrol and stop there, is likely a case as failing as at the civilization class. Countries could become civilized as they worked and deserved. Turkey is in a geopolitical and geo strategical geography between the Balkans and Middle East. She's also a bridge between Europe and Asia regarding exchange of cultures, civilization and industrialization. As an important developing country in the

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

    Rachid DEHINI


    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.

  1. Novel Active Combustion Control Valve

    Caspermeyer, Matt


    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.

  2. New Control Strategy of Hybrid Power Filter

    Škramlík, Jiří; Valouch, Viktor

    Madeira : APDEE, 2007, s. 1-6. ISBN 978-972-8822-08-8. [ Portuguese -Spanish Conference in Electrical Engineering - XCLEEE /10./. Madeira (PT), 05.07.2007-07.07.2007] R&D Projects: GA ČR GA102/06/0112 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filters * feedback and feedforward control strategy * unsymetrical and non-sinusoidal voltage system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    Yap Hoon


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

    Niiyama, K; Yagai, T; Tsuda, M; Hamajima, T [Graduate school of Engineering, Tohoku University, Sendai (Japan)], E-mail:


    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.

  5. Three-Phase Power Factor Controller

    Nola, F. J.


    Three-Phase Power-Factor Controller develops a control signal for each motor winding. As motor loading decreases, rms value of applied voltage is decreased by feedback-control circuit. Power consumption is therefore lower than in unregulated operation. Controller employs phase detector for each of three phases of delta-connected induction motor. Phase-difference sum is basis for control.

  6. Power control system and method

    Steigerwald, Robert Louis; Anderson, Todd Alan


    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  7. Advanced Coordinating Control System for Power Plant

    WU Peng; WEI Shuangying


    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.

  8. CCLIBS: The CERN Power Converter Control Libraries

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


    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...

  9. 单相有源PFC开环控制的研究%Research on Open Loop Control of Single-Phase Active Power Factor Corrector

    江剑峰; 杨喜军; 蒋婷; 曹中圣


    By now, in the field of single-phase active power factor correctors (PFC) , there are many control methods, which can be summarized into open control and closed control with their different merits and applicable scopes. In the paper, on the basis of the analysis of a single-phase active PFC principle needless of output voltage detection, an open loop control strategy is presented and analyzed only needing detection of post-bridge sinusoidal half-wave voltage, which can bring about follower characteristics versus input voltage and output power by means of regulation of the ratio between the mean output voltage and the RMS input voltage, and can also maintain the mean output voltage. After the simulation analysis by MATLAB/SIMULINK, a single-phase active PFC open digital control circuit based on DSP TMS320F28335 is designed and built into experimental platform and tested. The gained simulation and implementation results prove the theoretical analysis.%在单相有源PFC领域,截止目前,出现了多种控制方法,可以归类于开环控制和闭环控制,各有优缺点和所适用范围.在分析一种无需输出电压检测的单相PFC控制原理的基础上,提出和分析了一种只需检测整流桥后正弦半波电压和输出阻抗的开环控制策略,适合单级有源PFC和多级交错有源PFC,通过调节输出电压平均值与输入电压有效值之比,可以获得输出电压相对输入电压或输出功率的跟随特性,也可以维持输出电压平均值不变,在利用MATLAB/Simulink仿真分析后,基于DSPTMS320F28335设计了一种单相有源PFC的开环数字控制电路,建立实验平台进行实验测试.所得的仿真与实验结果符合相关的理论分析.

  10. The Real-Time Research of Optimal Power Flow Calculation in Reduce Active Power Loss Aspects of Power Grid

    Yuting Pan; Yuchen Chen; Zhiqiang Yuan; Bo Liu


    In order to research how to availably reduce the active power loss value in power grid system when the power system is operating, it offers a quantitative research in theory through conceiving the unbalanced losses of power grid system under the overloading bus as the investigative object, and establishing an active power loss mathematical model. It carries out online real-time optimal flow calculation within the condition that meets the control variables and state variables of the equality a...

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

    Abdul Basit


    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.

  12. Power flow control using quadrature boosters

    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.

  13. Active screening of magnetic field near power stations generator buses

    B.I. Kuznetsov


    Full Text Available An experimental study technique for a prototyping system of active screening of power-frequency magnetic field distortions near power station generator buses via controllable magnetic field sources is presented. Results of experimental research on a proto-typing active screening system with different control algorithms are given.

  14. Computerized control and management at the Temelin nuclear power plant

    The proposed automation of the nuclear power plant control system includes a division of the control system into three hierarchic levels, supplemented with an additional level. These comprise the automated system of control of technological processes, the all-plant control of the power-generating process, the control of backup activities and of technical and economic activities, and top managerial control. The efficiency of the nuclear power plant operation, i.e. attainment of the maximum electricity output with minimum costs while securing the required safety, is the principal criterion in the design of the data model. Listed are tasks that would lend themselves to automation within the automated system of nuclear power plant control, and the basic scheme of their automation as follows from an analysis performed at the Temelin nuclear power plant. (Z.S). 2 figs., 2 refs

  15. Water Turbine Power Control - Feasible Conception

    Němec, Zdeněk; Němec, Vojtěch


    This paper is concerned with Francis water turbine power control issue. There are introduced six conceptions of power controllers and corresponding control loop features are discussed. The control features are illustrated with step responses and the major attention is paid to the undesirable under-control effect. On an example of control system with an elementary description and with relatively short turbine pipeline feeder are the control features compared.

  16. Hierarchical power control of multiterminal HVDC grids

    Egea Àlvarez, Agustí; Beerten, Jef; van Hertem, Dirk; Gomis Bellmunt, Oriol


    This article introduces a hierarchical power control structure for Multi-terminal High Voltage Direct Current (MT-HVDC) systems. The presented hierarchy is similar to the control structure used in classical AC transmission systems and is divided in primary, secondary and tertiary control actions. The voltage control in the MT-HVDC scheme acts in a way similar to the primary control action of generators in AC systems, while the secondary control action is performed by an outer power control lo...

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

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


    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...

  18. Control of renewable distributed power plants

    Bullich Massagué, Eduard


    The main objective of this master thesis is to design a power plant controller for a photo- voltaic (PV) power plant. In a first stage, the current situation of the status of the electrical grid is analysed. The electrical network structure is moving from a conventional system (with centralized power generation, unidirectional power ows, easy control) to a smart grid system consisting on distributed generation, renewable energies, smart and complex control architecture and ...

  19. Control power in perfect controlled teleportation via partially entangled channels

    Li, Xi-Han; Ghose, Shohini


    We analyze and evaluate perfect controlled teleportation via three-qubit entangled channels from the point of view of the controller. The key idea in controlled teleportation is that the teleportation is performed only with the participation of the controller. We calculate a quantitative measure of the controller's power and establish a lower bound on the control power required for controlled teleportation. We show that the maximally entangled GHZ state is a suitable channel for controlled te...

  20. Nuclear Power Plant Control and Instrumentation 1989

    The meeting of the International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI) was organized in order to summarize operating experience of nuclear power plant control systems, gain a general overview of activities in development of modern control systems and receive recommendations on the further directions and particular measures within the Agency's programme. The meeting was held at the IAEA Headquarters in Vienna and was attended by 21 national delegates and observers from 18 countries. The present volume contains: (1) report on the meeting of the IWG-NPPCI, Vienna, 8-10 May 1989, (2) report of the scientific secretary on the major activities of IAEA during 1987-89 in the NPPCI area, (3) terms of reference International Working Group on NPPCI and (4) reports of the national representatives to the International Working Group on NPPCI. The paper and discussions with practical experience and described actual problems encountered. Emphasis was placed on the technical, industrial and economical aspects of the introduction of modern control systems and on the improvement of plant availability and safety. A separate abstract was prepared for each of the 19 papers presented by members of the International Working Group. Refs, figs and tabs

  1. Power, thermal, and attitude control design interactions of the CCE/AMPTE spacecraft. [Charge Composition Explorer/Active Magnetospheric Particle Tracer Explorers

    Wingate, C. A., Jr.; Allen, W. E.; Smola, J. F.; Ray, J. C.


    The power, thermal and attitude control interactions of the CCE spacecraft and the design compromises resulting from these interactions are described. These compromises result from the conflict between the plane change maneuver requirements and the final on station requirements. The resolution of these conflicts to arrive at an acceptable final design, is given and the resulting power, thermal and attitude control systems are described in some detail.

  2. High-power active devices

    Carroll, E


    Very high-power (HP) electronics represents a small part of the electronics market. In semiconductor terms, HP represents a world device market of 600 million euros out of a total 200 billion euros for all semiconductors—a mere 0.3 per cent. At the multi-megawatt spectral end, the numbers are even smaller, so that it is quite common for electronics engineers to be unaware of developments in Very High Power (VHP). In this presentation we discuss the categories of VHP active devices, the basic topologies in which they operate, and the trend towards higher voltage and current. New press-pack technologies are introduced and the salient differences between Insulated Gate Bipolar Transistors (IGBTs) and Integrated Gate Commutated Thyristors (IGCTs) are compared. Finally, recent developments in turn-off ratings for both these devices are presented.

  3. Active weld control

    Powell, Bradley W.; Burroughs, Ivan A.


    Through the two phases of this contract, sensors for welding applications and parameter extraction algorithms have been developed. These sensors form the foundation of a weld control system which can provide action weld control through the monitoring of the weld pool and keyhole in a VPPA welding process. Systems of this type offer the potential of quality enhancement and cost reduction (minimization of rework on faulty welds) for high-integrity welding applications. Sensors for preweld and postweld inspection, weld pool monitoring, keyhole/weld wire entry monitoring, and seam tracking were developed. Algorithms for signal extraction were also developed and analyzed to determine their application to an adaptive weld control system. The following sections discuss findings for each of the three sensors developed under this contract: (1) weld profiling sensor; (2) weld pool sensor; and (3) stereo seam tracker/keyhole imaging sensor. Hardened versions of these sensors were designed and built under this contract. A control system, described later, was developed on a multiprocessing/multitasking operating system for maximum power and flexibility. Documentation for sensor mechanical and electrical design is also included as appendices in this report.

  4. Integrated Coordinated Optimization Control of Automatic Generation Control and Automatic Voltage Control in Regional Power Grids

    Qiu-Yu Lu


    Full Text Available Automatic Generation Control (AGC and Automatic Voltage Control (AVC are key approaches to frequency and voltage regulation in power systems. However, based on the assumption of decoupling of active and reactive power control, the existing AGC and AVC systems work independently without any coordination. In this paper, a concept and method of hybrid control is introduced to set up an Integrated Coordinated Optimization Control (ICOC system for AGC and AVC. Concerning the diversity of control devices and the characteristics of discrete control interaction with a continuously operating power system, the ICOC system is designed in a hierarchical structure and driven by security, quality and economic events, consequently reducing optimization complexity and realizing multi-target quasi-optimization. In addition, an innovative model of Loss Minimization Control (LMC taking into consideration active and reactive power regulation is proposed to achieve a substantial reduction in network losses and a cross iterative method for AGC and AVC instructions is also presented to decrease negative interference between control systems. The ICOC system has already been put into practice in some provincial regional power grids in China. Open-looping operation tests have proved the validity of the presented control strategies.

  5. Power System Stability Enhancement Using Unified Power Flow Controller

    Prechanon Kumkratug


    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.

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

    Zbigniew Szczerba


    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.

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

    Grisby, Leonard L


    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 *

  8. 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



    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.

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

    Amir Kahyaei


    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.

  10. Statistical Performances of Resistive Active Power Splitter

    Lalléchère, Sébastien; Ravelo, Blaise; Thakur, Atul


    In this paper, the synthesis and sensitivity analysis of an active power splitter (PWS) is proposed. It is based on the active cell composed of a Field Effect Transistor in cascade with shunted resistor at the input and the output (resistive amplifier topology). The PWS uncertainty versus resistance tolerances is suggested by using stochastic method. Furthermore, with the proposed topology, we can control easily the device gain while varying a resistance. This provides useful tool to analyse the statistical sensitivity of the system in uncertain environment.

  11. Modular control of fusion power heating applications

    This work is motivated by the growing demand for auxiliary heating on small and large machines worldwide. Numerous present and planned RF experiments (EBW, Lower Hybrid, ICRF, and ECH) are increasingly complex systems. The operational challenges are indicative of a need for components of real-time control that can be implemented with a moderate amount of effort in a time- and cost-effective fashion. Such a system will improve experimental efficiency, enhance experimental quality, and expedite technological advancements. The modular architecture of this control-suite serves multiple purposes. It facilitates construction on various scales from single to multiple controller systems. It enables expandability of control from basic to complex via the addition of modules with varying functionalities. It simplifies the control implementation process by reducing layers of software and electronic development. While conceived with fusion applications in mind, this suite has the potential to serve a broad range of scientific and industrial applications. During the Phase-I research effort we established the overall feasibility of this modular control-suite concept. We developed the fundamental modules needed to implement open-loop active-control and demonstrated their use on a microwave power deposition experiment

  12. Modular control of fusion power heating applications

    Demers, D. R.


    This work is motivated by the growing demand for auxiliary heating on small and large machines worldwide. Numerous present and planned RF experiments (EBW, Lower Hybrid, ICRF, and ECH) are increasingly complex systems. The operational challenges are indicative of a need for components of real-time control that can be implemented with a moderate amount of effort in a time- and cost-effective fashion. Such a system will improve experimental efficiency, enhance experimental quality, and expedite technological advancements. The modular architecture of this control-suite serves multiple purposes. It facilitates construction on various scales from single to multiple controller systems. It enables expandability of control from basic to complex via the addition of modules with varying functionalities. It simplifies the control implementation process by reducing layers of software and electronic development. While conceived with fusion applications in mind, this suite has the potential to serve a broad range of scientific and industrial applications. During the Phase-I research effort we established the overall feasibility of this modular control-suite concept. We developed the fundamental modules needed to implement open-loop active-control and demonstrated their use on a microwave power deposition experiment.

  13. Linguistic control of a nuclear power plant

    A multivariable linguistic controller based on fuzzy set theory is discussed and its application to a pressurized water nuclear power plant control is illustrated by computer simulation. The nonlinear power plant simulation model has nine states, two control inputs, one disturbance input, and two outputs. Although relatively simple, the model captures the essential coupled nonlinear plant dynamics and is convenient to use for control system studies. The use of an adaptive version of the controller is also demonstrated by computer simulation

  14. Control Architecture for Future Power Systems

    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...

  15. Optically powered active sensing system for Internet Of Things

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


    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.

  16. Adaptive intelligent power systems: Active distribution networks

    Electricity networks are extensive and well established. They form a key part of the infrastructure that supports industrialised society. These networks are moving from a period of stability to a time of potentially major transition, driven by a need for old equipment to be replaced, by government policy commitments to cleaner and renewable sources of electricity generation, and by change in the power industry. This paper looks at moves towards active distribution networks. The novel transmission and distribution systems of the future will challenge today's system designs. They will cope with variable voltages and frequencies, and will offer more flexible, sustainable options. Intelligent power networks will need innovation in several key areas of information technology. Active control of flexible, large-scale electrical power systems is required. Protection and control systems will have to react to faults and unusual transient behaviour and ensure recovery after such events. Real-time network simulation and performance analysis will be needed to provide decision support for system operators, and the inputs to energy and distribution management systems. Advanced sensors and measurement will be used to achieve higher degrees of network automation and better system control, while pervasive communications will allow networks to be reconfigured by intelligent systems

  17. DSP Control of Line Hybrid Active Filter

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


    Active Power Filters have been intensively explored in the past decade. 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 Le filter and a small-rated power active filter, which are directly connected in series without any matching transformer. Thus the required rating of the active filter is much smaller than a conventional standalone...... active filter. Simulation and experimental results obtained in laboratory confirmed the validity and effectiveness of the control....

  18. Power Control Method for Research Reactor

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


    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.

  19. 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.

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


    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. PMID:27018144

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

    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.

  1. Control of Power Converters in AC Microgrids

    Rocabert, Joan; Luna, Alvaro; Blaabjerg, Frede; Rodriguez, Pedro


    electrical system. The high penetration of distributed generators, linked to the grid through highly controllable power processors based on power electronics, together with the incorporation of electrical energy storage systems, communication technologies, and controllable loads, opens new horizons to the...... effective expansion of microgrid applications integrated into electrical power systems. This paper carries out an overview about microgrid structures and control techniques at different hierarchical levels. At the power converter level, a detailed analysis of the main operation modes and control structures...... for power converters belonging to microgrids is carried out, focusing mainly on grid-forming, grid-feeding, and grid-supporting configurations. This analysis is extended as well toward the hierarchical control scheme of microgrids, which, based on the primary, secondary, and tertiary control layer...

  2. Laser welding closed-loop power control

    Bagger, Claus; Olsen, Flemming Ove


    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....

  3. The Large Customer Reactive Power Control Possibilities

    Robert Małkowski; Zbigniew Szczerba


    In this paper the authors wish to draw attention to the rationale for, and the possibility of, the use of local reactive power sources by the Transmission Node Master Controller (TNMC). Large Customers (LC) are one of the possible reactive power sources. The paper presents the issues related to the need for coordination between the control systems installed in the LC network, and coordination between control systems of the LC as well as master control systems in the network.

  4. 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

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


    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.

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

    Aman Abdulla Tanvir; Adel Merabet; Rachid Beguenane


    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 pow...

  6. Power Oscillation Damping Controller for Wind Power Plant Utilizing Wind Turbine Inertia as Energy Storage

    Knüppel, Thyge; Nielsen, Jørgen Nygård; Jensen, Kim Høj;


    utilizes the stored kinetic energy in the wind turbine (WT) mechanical system as energy storage from which damping power can be exchanged. This eliminates the need for curtailed active power production. Results are presented using modal analysis and induced torque coefficients (ITC) to depict the torques......For a wind power plant (WPP) the upper limit for active power output is bounded by the instantaneous wind conditions and therefore a WPP must curtail its power output when system services with active power are delivered. Here, a power oscillation damping controller (POD) for WPPs is presented that...... induced on the synchronous generators from the POD. These are supplemented with nonlinear time domain simulations with and without an auxiliary POD for the WPP. The work is based on a nonlinear, dynamic model of the 3.6 MW Siemens Wind Power wind turbine....

  7. Thermal power plant simulation and control

    Flynn, Damian


    Contributors of world-class excellence are brought together in Thermal Power Plant Simulation and Control to illustrate how current areas of research can be applied to power plant operation, leading to enhanced unit performance, asset management andplant competitiveness through intelligent monitoring and control strategies.

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

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


    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...... as wind turbine (WT) terminal, collector cable, and export cable, on the dynamic voltage profile of the offshore grid is investigated. Furthermore, the dynamic reactive power contribution from WTs from different WPPs of the cluster for such faults has also been studied....... reactive power set point, the OWPP cluster controller generates reactive power references for each WPP which further sends the AC voltage/ reactive power references to the associated WTs based on their available reactive power margin. The impact of faults at different locations in the offshore grid, such...

  9. Thyristor Controlled Reactor for Power Factor Improvement

    Sheila Mahapatra


    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.

  10. Development of nuclear power control technology

    The status on the development of nuclear power control(NPC) technology were reviewed. The advance of the fuzzy control and neural network(NN) control method for nuclear power plant was analyzed emphatically. The new trend of NPC technology advance was explored. The results of analysis reveal that the advancing tendency of NRC technology is developing from classical control to advanced control and intelligent control in the control method; the NPC technology is developing from simulated technology to digital (computer) technology and network technology in the hardware technology; the NPC system is progressing from single loop control to supervisory control, distributed computer control and control network-based in the the hierarchy of control system. In the NPC system, the PID method is still a most important control method, the fuzzy control method have good performance and the neural network method has great potential for the control of nuclear power plant. However, it is necessary to test and demonstrate for the application of neural network control to the nuclear power plant. (authors)

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

    Momoh, James A


    * 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

  12. 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

    林俐; 谢永俊; 朱晨宸; 汪宁渤


    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

  13. On load flow control in electric power systems

    Herbig, Arnim


    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

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

    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)


    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.)

  15. Modeling Control Situations in Power System Operations

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


    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...

  16. Optimal control systems in hydro power plants

    The aim of the research done in this work is focused on obtaining the optimal models of hydro turbine including auxiliary equipment, analysis of governors for hydro power plants and analysis and design of optimal control laws that can be easily applicable in real hydro power plants. The methodology of the research and realization of the set goals consist of the following steps: scope of the models of hydro turbine, and their modification using experimental data; verification of analyzed models and comparison of advantages and disadvantages of analyzed models, with proposal of turbine model for design of control low; analysis of proportional-integral-derivative control with fixed parameters and gain scheduling and nonlinear control; analysis of dynamic characteristics of turbine model including control and comparison of parameters of simulated system with experimental data; design of optimal control of hydro power plant considering proposed cost function and verification of optimal control law with load rejection measured data. The hydro power plant models, including model of power grid are simulated in case of island ing and restoration after breakup and load rejection with consideration of real loading and unloading of hydro power plant. Finally, simulations provide optimal values of control parameters, stability boundaries and results easily applicable to real hydro power plants. (author)

  17. Modular supervisory controller for hybrid power systems

    Lemos Pereira, A. de


    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)

  18. Stability and control of wind farms in power systems

    Jauch, C.


    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

  19. Application of H∞ control theory to PWR power control

    In this paper, a robust controller is designed by the use of H∞ control theory for the PWR power control. The design specification is incorporated by the frequency weights using the mixed-sensitivity problem. The robustness of H∞ control is verified by comparing with the classical output feedback control and LQG control in the case of measurement delay of the power measurement system. The H∞ optimal control shows excellent stability-robustness and performance-robustness for external disturbances and noises, model parameter variations, and modeling errors. It also provides a practical design method because the design specification can be easily implemented

  20. Active control of radiated sound using nearfield pressure sensing

    CHEN Ke'an; YIN Xuefei


    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.

  1. reactor power control using fuzzy logic

    power stabilization is a critical issue in nuclear reactors. convention pd- controller is currently used in egypt second testing research reactor (ETRR-2). two fuzzy controllers are proposed to control the reactor power of ETRR-2 reactor. the design of the first one is based on a set of linguistic rules that were adopted from the human operators experience. after off-line fuzzy computations, the controller is a lookup table, and thus, real time controller is achieved. comparing this f lc response with the pd-controller response, which already exists in the system, through studying the expected transients during the normal operation of ETRR-2 reactor, the simulation results show that, fl s has the better response, the second controller is adaptive fuzzy controller, which is proposed to deal with system non-linearity . The simulation results show that the proposed adaptive fuzzy controller gives a better integral square error (i se) index than the existing conventional od controller

  2. Control System for Electromagnet Power Supplies

    Ermolov, E. Y.; Kozak, V. R.; Kuper, E. A.; Medvedko, A. S.; Petrov, S. P.; Veremeenko, V. F.


    A set of power supplies (PS) with output power rated from 100 W up to 10 kW for electromagnets powering was developed. These PS have range of current tuning of 60-80 db with high accuracy (error should be less than 0,01%). Some types of power supplies have bipolar output current. The report will describe a set of unified embedded devices for control and measurements of PS incorporated into distributed control systems. These embedded devices includes DAC, ADC with multiplexers and status Input...

  3. The SSRF power supply control system

    The SSRF power supply control system is a fully distributed control system based on the EPICS system. About 65K runtime database records run in the 27 VME/IOC controllers to make physics access more than 600 sets of power' supplies distributed in the SSRF facility. In this paper, the layered system architecture and its working principles are introduced. The EPICS-based control solutions for the PSI-designed and SINAP-designed digital controllers are described. The hardware and software, together with the communication technology applied in the system, are presented. (authors)

  4. Selective harmonic control for power converters

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede; Lu, Wenzhou; Danwei, Wang

    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....

  5. Hydraulically powered dissimilar teleoperated system controller design

    This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented

  6. Power grid control in retreat

    Bilateral grid control that obstructs free trade of electricity is in retreat. Negotiations on opening the Skagerrak cables are in progress. The EU, national authorities, network companies with system responsibility, market actors, electricity exchanges all push for quick opening of the grid. At present, free trade of electricity is hindered not so much by physical bottlenecks in the grid as by market actors possessing control and bilateral agreements. The article discusses current bilateral agreements and how they might affect the possibility of a free trade of electricity in Europe

  7. Power electronic converters modeling and control with case studies

    Bacha, Seddik; Bratcu, Antoneta Iuliana


    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...

  8. Power flow analysis of a power system in the presence of interline power flow controller (IPFC)

    T. Ramana; Ch. Padmanabharaju; S.Sivanagaraju; A. V. Naresh Babu


    One of the latest generation flexible AC transmission systems (FACTS) controllers is interline power flow controller (IPFC). In general, it is connected in multiple transmission lines of a power system network. This paper presents power injection model (PIM) of IPFC. This model is incorporated in Newton-Raphson (NR) power flow algorithm to study the effect of IPFC parameters in power flow analysis. A program in MATLAB has been written in order to extend conventional NR algorithm based on this...

  9. Optimal control applications in electric power systems

    Christensen, G S; Soliman, S A


    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...

  10. Nuclear power plant control system

    Purpose: To effectively transfer the operation of a nuclear power plant including a bwr type reactor to single load operation in the station with no increase in the neutron flux and water level in the reactor by the combined use of recycle pump trip and feedwater pump trip. Method: Upon rapid load decrease in a turbine generator, at least one of usually operated feedwater pumps and a recycle pump are tripped and the starting for a stand-by feedwater pump is inhibited. This rapidly decreases the recycling flow rate to thereby lower the neutron flux before generation of pressure increase and also decreases the feedwater flow rate to thereby suppress the increase in the water level due to increase in voids, whereby the operation is smoothly transferred to the single load operation in the station. (Horiuchi, T.)

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

    Yogita Kumari


    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.

  12. Phase Detector for Power-Factor Controller

    Nola, F. J.


    Positive feedback assures reliable switching. Three Phase Power Factor Controller includes three phase detectors, each produces rectangular waves of duration approximately equal to lag time between line voltage and motor current.

  13. Controlled Compact High Voltage Power Lines

    Postolati V.


    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.

  14. Microgrid Control Techniques at Power Converter Level

    Valouch, Viktor; Šimek, Petr; Škramlík, Jiří; Tlustý, J.

    Ostrava: VŠB - TU Ostrava, 2013, s. 611-616. ISBN 978-80-248-2988-3. [Electric Power Engineering - EPE 2013. Kouty nad Desnou (CZ), 28.05.2013-30.05.2013] Institutional support: RVO:61388998 Keywords : microgrid * power converter * droop control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  15. Remotely powered and controlled EAPap actuator by amplitude modulated microwaves

    This paper reports on a remotely powered and controlled Electro-Active Paper (EAPap) actuator without onboard controller using amplitude modulated microwaves. A rectenna is a key element for microwave power transmission that converts microwaves into dc power through coupling and rectification. In this study, the concept of a remotely controlled and powered EAPap actuator is proposed by means of modulating microwaves with a control signal and demodulating it through the rectenna rectification. This concept is applied to a robust EAPap actuator, namely cellulose–polypyrrole–ionic liquid (CPIL) EAPap. Details of fabrication and characterization of the rectenna and the CPIL-EAPap actuator are explained. Also, the charge accumulation problem of the actuator is explained and resolved by connecting an additional resistor. Since this idea can eliminate the onboard controller by supplying the operating signal through modulation, a compact and lightweight actuator can be achieved, which is useful for biomimetic robots and remotely driven actuators. (technical note)

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

    Toigo, V., E-mail: [Consorzio RFX - EURATOM - ENEA Association, 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, Stati Uniti 4, 35127 Padova (Italy)


    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.

  17. Hybrid wind power balance control strategy using thermal power, hydro power and flow batteries

    Gelazanskas, Linas; Baranauskas, Audrius; Gamage, Kelum; Azubalis, Mindaugas


    The increased number of renewable power plants pose threat to power system balance. Their intermittent nature makes it very difficult to predict power output, thus either additional reserve power plants or new storage and control technologies are required. Traditional spinning reserve cannot fully compensate sudden changes in renewable energy power generation. Using new storage technologies such as flow batteries, it is feasible to balance the variations in power and voltage within very short...

  18. Power system dynamics stability and control

    Padiyar, K R


    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.

  19. Facts controllers in power transmission and distribution

    Padiyar, KR


    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

  20. Adaptive control of active filter using DSP

    In order to reduce output-voltage ripple of power supply, an active filter is necessary. In this paper, the active filter with DSP is proposed. The waveform from active filter can be flexibly improved by DSP programming. The output-voltage ripple can be enough reduced by mixing frequency components of the input-voltage ripple. The result of adaptive control using LMS algorism is presented. The improvement by using filtered-X method is discussed. (author)

  1. Robust Decentralized Control of Unified Power Flow Controller

    Hossein Shayeghi


    Full Text Available A new approach based on structured singular value is proposed for the robust decentralized Unified Power Flow Controller (UPFC design. To achieve decentralization, using the schauder fixed point theorem the synthesis and analysis of Multi-Input Multi-output (MIMO control system is translated into set of equivalent Multi-Input Single-Output (MISO control system. Power systems such as the other industrial plants contain different kinds of uncertainties, which should be considered in controller design procedure. For this reason, the idea of µ-synthesis technique was used for designing of UPFC controllers. The proposed µ-based controller has a decentralized scheme and advantage of a decentralized controller design is reduction in the controller complexity and suitability for practical implementation. The effectiveness of the proposed control strategy was evaluated under operating conditions for damping low frequency oscillations in comparison with the classical controller to demonstrate its robust performance through nonlinear time simulation and some performance indices.

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

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


    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...

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

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


    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 changes (TG vs. CG; pchange 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, pmobility-limited older adults following 12-weeks of progressive power 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. PMID:27090485

  4. 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

    贺永平; 庄圣贤


    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。

  5. Power flow control of intertied ac microgrids

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


    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 with...

  6. Efficiency in Controlling Activities

    Van Nguyen, Tuyen


    Controlling is essential for financial success of corporations. An efficient controlling system should be implemented in order to manage financial performance from income, expense to profitability. The purpose of the thesis is to provide insight knowledge towards corporate accounting management as well as to propose potential improvement for the existing controlling system of the case company, which is Bosch Rexroth Japan. The theoretical framework creates the knowledge foundation for re...

  7. Comparison of Power Control Strategies for DFIG Wind Turbines

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


    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...

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

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


    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...... 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...... time. Therefore, deciding the amount of non-active currents (fundamental, 5th and 7th harmonics) to be injected depending on the PCC voltage quality. Experimental results of the proposed control strategy are analyzed in order to validate the performance of the entire system....

  9. Modelling supervisory controller for hybrid power systems

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


    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)

  10. Fractional Power Control for Decentralized Wireless Networks

    Jindal, Nihar; Andrews, Jeffrey G


    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.