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A Novel Fuzzy—Adaptive Hysteresis Controller Based Three Phase Four Wire-Four Leg Shunt Active Filter for Harmonic and Reactive Power Compensation  [PDF]
P. Rathika, D. Devaraj
Energy and Power Engineering (EPE) , 2011, DOI: 10.4236/epe.2011.34053
Abstract: This paper presents a fuzzy logic based three phase four wire four-leg shunt active power filter to suppress harmonic currents. Modified instantaneous p-q theory is adopted for calculating the compensating current. Fuzzy-adaptive hysteresis band technique is applied for the current control to derive the switching signals for the voltage source inverter. A fuzzy logic controller is developed to control the voltage of the DC capacitor. Computer simulations are carried out on a sample power system to demonstrate the suitability of the proposed control strategy, for harmonic reduction under three different conditions namely, ideal, unbalance, unbalance and distorted source voltage conditions. The proposed control strategy is found to be effective to reduce the harmonics and compensate reactive power and neutral current and balance load currents under ideal and non-ideal source voltage conditions.
A Three Phase Shunt Active Power Filter for Currents Harmonics Suppression and Reactive Power Compensation
A. Omeiri,A. Haddouche,L. Zellouma,S. Saad
Asian Journal of Information Technology , 2012,
Abstract: This study presents a three phase shunt active power filter for current harmonics suppression and reactive power compensation using the supply current as reference. The proposed APF has a simple control circuit; it consists of detecting the supply current instead of the load current. The advantages of this APF are simplicity of control circuits and low implementation cost. The simulation results show that the proposed APF can compensate the reactive power and suppress current harmonics with two types of non-linear loads.
Enhanced active power filter control for nonlinear non-stationary reactive power compensation  [PDF]
Phen Chiak See,Vin Cent Tai,Marta Molinas,Kjetil Uhlen,Olav Bjarte Fosso
Mathematics , 2012,
Abstract: This paper describes a method to implement Reactive Power Compensation (RPC) in power systems that possess nonlinear non-stationary current disturbances. The Empirical Mode Decomposition (EMD) introduced in the Hilbert-Huang Transform (HHT) is used to separate the disturbances from the original current waveform. These disturbances are subsequently removed. Following that, Power Factor Correction (PFC) based on the well-known p-q power theory is conducted to remove the reactive power. Both operations were implemented in a shunt Active Power Filter (APF). The EMD significantly simplifies the singulation and the removal of the current disturbances. This helps to effectively identify the fundamental current waveform. Hence, it simplifies the implementation of RPC on nonlinear non-stationary power systems.
Simulation of Fuzzy Logic Based Shunt Hybrid Active Filter for Power Quality Improvement
Sakshi Bangia,P R Sharma,Maneesha Garg
International Journal of Intelligent Systems and Applications , 2013,
Abstract: This paper deals with the implementation of fuzzy logic based Shunt Hybrid Active Filter (SHAF) with non-linear load to minimize the source current harmonics and provide reactive power compensation. Comparison with Proportional Integral (PI) based SHAF is also analyzed. Shunt Hybrid Active Filter is constituted by Active Filter connected in shunt and shunt connected three phase single tuned LC filter for 5th harmonic frequency with rectifier load. The Active Filtering System is based on Synchronous Reference Frame. The proposed fuzzy logic based control strategy improves active filter operation and reduces the selective harmonic contents. The control strategies are demonstrated through MATLAB Simulated Environment.
Harmonics and Reactive Power Compensation Using Shunt Hybrid Filter  [cached]
R. Sriranjani,M. Geetha,S. Jayalalitha
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: The supply current is distorted by the nonlinear load such UPS, DC drives, AC drives and arc furnace. This current harmonics derates the electrical equipments. Thus the current harmonics are reduced from the supply line using Shunt Hybrid filter. The Hysteresis controller controls the active filter thus the supply current tracks the reference fundamental current extracted by the synchronous reference frame unit. So supply current is free from harmonics and also it provides harmonic compensation. The passive filter is tuned for the dominant harmonic frequency so it reduces the rating of the active filter. The total harmonic distortion and power factor of the supply current of three phase controlled rectifier load with filter and without filter is analyzed using MATLAB simulink and the results are presented.
Design of Shunt Active Power Filter to eliminate the harmonic currents and to compensate the reactive power under distorted and or imbalanced source voltages in steady state  [PDF]
Sangu Ravindra#1, Dr.V.C.Veera Reddy#2, Dr.S.Sivanagaraju#3
International Journal of Engineering Trends and Technology , 2011,
Abstract: The shunt active power filter has proved to be a useful device to eliminate harmonic currents and to compensate reactive power for linear/nonlinear loads. This paper presents a novel approach to determine reference compensation currents of the three-phase shunt active power filter (APF) under distorted and/or imbalanced source voltages in steady state. The proposed approach is compared with three reviewed shunt APF reference compensation strategies. Results obtained by simulations with Matlab and Simulink show that the proposed approach is more effective than the reviewed approaches on compensating reactive power and harmonic/neutral currents of the load, even if the source voltages are severely distorted and imbalanced. In addition, the proposed approach yields a simpler design of the shunt APF controller.
SEVEN LEVEL CONTROL OF SHUNT ACTIVE POWER FILTER FOR POWER QUALITY ENHANCEMENT  [PDF]
G. JAYAKRISHNA,P.SUJATHA,K.S.R.ANJANEYULU
International Journal of Engineering Science and Technology , 2011,
Abstract: Shunt Active Power Filter (SAPF) is one of the controllers to enhance power quality (PQ). This paper presents Hybrid Cascaded Seven-Level Inverter (HCSLI) used in SAPF to compensate reactive power, improve the power factor and to suppress the total harmonic distortion (THD) in supply current due to linear load and Non- Linear Diode Rectifier Loads (NLDRLs).In this paper d-q reference frame theory for reference current computation, Constant Switching Frequency Multicarrier Sub-Harmonic Pulse Width Modulation (CSFMSHPWM) technique for controlling the switches of HCSLI, Fuzzy logic controller (FLC) for regulating dc side capacitor voltage are proposed. The results are validated through simulation using Mat Lab/simulink with and without SAPF for linear and nonlinear loads.
Adaptive Fuzzy Control with Supervisory Compensator for Three-Phase Active Power Filter  [PDF]
Juntao Fei,Shixi Hou
Journal of Applied Mathematics , 2012, DOI: 10.1155/2012/654937
Abstract: An adaptive fuzzy control system with supervisory controller is proposed to improve dynamic performance of three-phase active power filter (APF). The proposed adaptive fuzzy controller for APF does not build an accurate mathematical model but approximates the nonlinear characteristics of APF using fuzzy approximation. The adaptive law based on the Lyapunov analysis can adaptively adjust the fuzzy rules; therefore the asymptotical stability of the adaptive fuzzy control system can be guaranteed. Simulation results demonstrate that the APF control system has excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD) index, strong robustness in the presence of parameters variation, and nonlinear load. 1. Introduction A variety of nonlinear and time-varying electronic devices bring power quality problems to the power system such as low power factor, waveform distortion, surges, and phase distortion problems. Active power filter can be used for power system harmonic suppression and reactive current compensation. The basic principle of APF is to produce compensation current that is of the same amplitude and opposite phase with the harmonic currents to eliminate the unexpected harmonic currents. Therefore active power filters are widely used in many applications to compensate the harmful harmonic currents produced by nonlinear loads on industrial, commercial, and residential equipment. In the last few years, fuzzy control has been extensively applied in a wide variety of industrial systems and consumer products because of its model-free approach. Wang [1] proposed universal approximation theorem and demonstrated that an arbitrary function of a certain set of functions can be approximated with arbitrary accuracy using fuzzy system on a compact domain. Therefore fuzzy logic system to approximate arbitrary nonlinear functions makes it a useful tool for adaptive application. Guo and Woo [2] proposed adaptive fuzzy sliding mode controller for robot manipulator. Yoo and Ham [3] developed adaptive controller for robot manipulator using fuzzy compensator. In this paper, intelligent controllers like fuzzy logic controller will be investigated to approximate nonlinear dynamic systems as APF. There are many current tracking control methods, such as single cycle control, hysteresis current control, space vector control, sliding mode control, deadbeat control, repetitive control, predictive control, fuzzy control, adaptive control, iterative learning control, and artificial neural network control. Singh et al. [4] presented
Fuzzy Controller Based 3Phase 4Wire Shunt Active Filter for Mitigation of Current Harmonics with Combined p-q and Id-Iq Control Strategies  [PDF]
Mikkili Suresh, Anup Kumar Panda, Y. Suresh
Energy and Power Engineering (EPE) , 2011, DOI: 10.4236/epe.2011.31007
Abstract: As more and more variable frequency drives (VFDs), electronic ballasts, battery chargers, and static Var compensators are installed in facilities, the problems related to harmonics are expected to get worse. As a result Active power filter (APF) gains much more attention due to excellent harmonic compensation. But still the performance of the active filter seems to be in contradictions with different control strategies. This paper presents detailed analysis to compare and elevate the performance of two control strategies for ex-tracting reference currents of shunt active filters under balanced, un-balanced and non-sinusoidal conditions by using Fuzzy controller. The well known methods, instantaneous real active and reactive power method (p-q) and active and reactive current method (id-iq) are two control methods which are extensively used in active filters. Extensive Simulations are carried out with fuzzy controller for both p-q and Id-Iq methods for different voltage conditions and adequate results were presented. Simulation results validate the superior per-formance of active and reactive current control strategy (id-iq) with fuzzy controller over active and reactive power control strategy (p-q) with fuzzy controller.
ANN Current Controller Based on PI-Fuzzy Adaptive System for Shunt Power Active Filter  [PDF]
Moulay Tahar Lamchich
Advances in Power Electronics , 2012, DOI: 10.1155/2012/237259
Abstract: This paper deals with the use of triphase shunt active filter which is able to compensate current harmonics, reactive power, and current unbalance produced by nonlinear loads. To perform the identification of disturbing currents, a very simple control method is introduced. It’s formed by a DC voltage regulator and a balance between the average power of load and the active power supplied by the grid. The output current of the voltage source inverter (VSI) must track the reference current. This is done by a neural controller based on a PI-Fuzzy adaptive system as reference corrector. Also to regulate the DC link capacitor voltage a fuzzy logic adaptive PI controller is used. 1. Introduction Due to the increased use of nonlinear electrical loads, such as power electronics supplies, harmonics currents are generated in the level of these loads and injected back to the grid causing its voltage distortion at harmonics currents’ frequencies. The distorted voltage generates distorted currents which will be absorbed by sensitive loads and causing losses in the lines. Also, the most consuming electrical power loads are almost inductive, and then they contribute to the degradation of grid power factor at the point of common connection (PCC). Conventionally, passive filters were adopted for the reduction of harmonics and to improve power factor; therefore, they have the disadvantages such as fixed frequency compensation, resonance, and large size. These limitations were avoided by the use of active filters which utilized a switch-mode power electronic converter to supply harmonic currents equal to those in the load currents. The main objective of the power active filter (PAF) is to compensate reactive power, current harmonics, neutral current, and unbalancing of nonlinear loads by injecting compensating currents. Almost, the method-based instantaneous active and reactive power (pq method) [1] is currently performed for disturbing current identification. The major disadvantages of a bloc identification-based pq method are essentially as follows:(i)it is not effective under distorted and unbalanced mains voltages conditions;(ii)the time delays introduced by pass filters, which are used to separate the average and oscillating parts of powers, degrades the dynamic performance of active filter;(iii) this method requires more computational calculation. The controller of the PAF is comprised of an inner current loop which actively shapes the line currents and an outer voltage control loop which regulates the magnitude of the line currents. This paper presents the
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