Three-phase Shunt Active Power Filter Research Articles

Performance Investigation of Active Power Filter Under Non-Linear Loads Variation

This paper aims on details performance of three-phase shunt active power filter (APF) having variation of DC non-linear loads implemented in real-time control using dSPACE DS 1104 is presented. The APF was implemented by using stationary reference frame (d-q algorithm) and the purpose is to extract the harmonics content in the system. In addition, 9 kHz carrier signal are used to generated the switching signal which are used to correct the harmonics in the system. The non-linear loads were constructed with three-phase rectifier which connected in series with inductor and parallel with resistor and capacitor. In this experiment, three cases have been investigated to analyze the performance of the APF. The results shows the improvement of the THDi are ranging from 92% to 94%. The best reduction of the THDi are founded with both load at maximum values

Fast-Transient Repetitive Control Strategy for a Three-phase LCL Filter-based Shunt Active Power Filter

A fast-transient repetitive control strategy for a three-phase shunt active power filter is presented in this study to improve dynamic performance without sacrificing steady-state accuracy. The proposed approach requires one-sixth of the fundamental period required by conventional repetitive control methods as the repetitive control time delay in the synchronous reference frames. Therefore, the proposed method allows the system to achieve a fast dynamic response, and the program occupies minimal storage space. A proportional-integral regulator is also added to the current control loop to eliminate arbitrary-order harmonics and ensure system stability under severe harmonic distortion conditions. The design process of the corrector in the fast-transient repetitive controller is also presented in detail. The LCL filter resonance problem is avoided by the appropriately designed corrector, which increases the margin of system stability and maintains the original compensation current tracking accuracy. Finally, experimental results are presented to verify the feasibility of the proposed strategy.

A Novel Control Strategy of Active Power Filter

To improve the dynamic response and of compensation characteristic three-phase shunt active power filter(APF),a novel control strategy was proposed based on supply voltage detection. Fundamental wave current controller and dc side voltage controller was designed in detail. This method can not only compensate the parameter is determined and position distortion load, also can compensate the uncertain load.The superiority of the control architecture proposed is verified completely by simulation results.

Performance comparison of shunt active power filter for interval type-2 fuzzy and adaptive backstepping controllers

The control technique used with the three-phase shunt active power filter (SAPF), has an important role in its performance. In this paper, a comparison between the SAPF performance controlled with interval type-2 fuzzy controller (IT2FC), adaptive backstepping non-linear control (ABNC), and proportional integral (PI) controllers is accomplished. The simulation results show the key features of each technique. It is also found that the parameters’ variations and uncertainties of the system can be compensated by ABNC or IT2FC controllers without any prior knowledge of real parameters. However, ABNC has better performance than the IT2FC.

An improved deadbeat control algorithm for three-phase four-leg shunt active power filter

ABSTRACTConsidering the influence of the alternating current side resistor, this paper completes the mathematical model for the three-phase four-leg active power filter and deduces the discrete model of the deadbeat control. A novel delay compensation method is proposed to improve the deadbeat control algorithm. Comparing with the algorithm without delay compensation, the proposed algorithm can effectively reduce the delays caused by digital computing and pulse width modulation output. This is achieved by increasing thë sampling and processing frequency without estimating the actual values. The predictive algorithms are also analysed in this paper. For the improved algorithm, the simulation and experimental results show that the total harmonic distortion values of three-phase source currents become lower and the neutral current becomes smaller than the algorithm without delay compensation. Therefore the proposed algorithm can solve the harmonic and unbalancing problems effectively.

An Advanced Current Control Strategy for Three-Phase Shunt Active Power Filters

This paper proposes an advanced control strategy to enhance performance of shunt active power filter (APF). The proposed control scheme requires only two current sensors at the supply side and does not need a harmonic detector. In order to make the supply currents sinusoidal, an effective harmonic compensation method is developed with the aid of a conventional proportional-integral (PI) and vector PI controllers. The absence of the harmonic detector not only simplifies the control scheme but also significantly improves the accuracy of the APF, since the control performance is no longer affected by the performance of the harmonic tracking process. Furthermore, the total cost to implement the proposed APF becomes lower, owing to the minimized current sensors and the use of a four-switch three-phase inverter. Despite the simplified hardware, the performance of the APF is improved significantly compared to the traditional control scheme, thanks to the effectiveness of the proposed compensation scheme. The proposed control scheme is theoretically analyzed, and a 1.5-kVA APF is built in the laboratory to validate the feasibility of the proposed control strategy.

Design of LCL-Filter with Active Damping for Active Power Filter

In this paper, the influence of gird-side and inverter-side inductance on LCL-filter performance is studied. The design method of LCL-filter applied in three-phase shunt active power filter (SAPF) is proposed. An active damping strategy using the current feedback of the filter capacitor is adopted to suppress the resonance. A practical example is designed using the proposed design procedure. Finally, Simulation and experimental results verify the feasibility of the design method.

The Simulation Study of Shunt Active Power Filter in the Power System Harmonics Restraint

because of the existence of non-linear loads,they will be inpouring a lot of harmonic current to the power system,in order to restrain harmonic,we have to take relevant measures to restrain. This paper introduces three measures of harmonic restraint firstly, expounds the active power filter, and then it analyses the work principle and mathematical model of shunt active power filter , building three-phase shunt active power filter simulation model,; At last, using MATLAB simulation experiment ,the result shows that the shunt active power filter of harmonic detection algorithm and the control strategy are correct and effective , and also it has the important significance to the power system harmonic restraint.

Control Strategy for Shunt Active Power Filters with Selective Harmonic Compensation

To improve the flexibility of compensation and the precision of three-phase shunt active power filter (APF). A double-loop compound current controller was proposed, which repetitive controller as the outer loop, the PI controller as the inner loop. Design method in detail, dynamic response and steady-state characteristic in analysis. And put forward the compound control strategy, which combine selective harmonic detection based on multiple synchronous rotating coordinates with double-loop compound controller, achieved the compensation of zero steady-state error and selective harmonic currents. Both simulation and experimental results verify the effectiveness and correctness of the content.

An efficient reference compensation current strategy of three-phase shunt active power filter implemented with processor-in-the-loop simulation

SUMMARY This paper proposes an efficient method to obtain the equivalent fundamental positive-sequence voltage for determining the shunt active power filter (APF) reference compensation currents, where the source voltage magnitude and phase angle at the fundamental frequency are detected by a simplified adaptive linear combiner neural network. The APF reference current calculator is developed and is realized on the DSP board through processor-in-the-loop (PIL) simulation for validating the effectiveness of the proposed APF control strategy, where the source voltages and the load currents are both distorted and unbalanced. In addition, results obtained based on the true positive-sequence fundamental source current after APF compensation and another classic approach are included for comparison. It is shown that results obtained by the PIL simulations with the proposed and compared methods agree very well. The proposed APF reference compensation current strategy is simple and practical, which provides a cost-effective and computationally efficient manner for the APF controller implementation with PIL simulations. Copyright © 2013 John Wiley & Sons, Ltd.

Sliding mode Control using 3D-SVM for Three-phase Four-Leg Shunt Active Filter

This paper proposes a sliding mode control strategy for a three-phase shunt active power filter. The SAPF consists of four-leg voltage source inverter bridge. The SAPF ensures full compensation for harmonic phase currents, harmonic neutral current, reactive power compensation and unbalanced nonlinear load currents. The modulation task can be carried out with three dimensional space vector modulation, which operate under a constant switching frequency. The simulation results show that the performance of the four-leg SAPF with the proposed control algorithm – compared with PI controller - is found considerably effective and adequate to compensate harmonics, reactive power, neutral current and balance load currents.

Adaptive nonlinear control of three-phase shunt active power filters

The problem of controlling three-phase shunt active power filters (SAPF) is addressed in presence of nonlinear loads supplied with three-phase power grids. The SAPF-load system is shown to be modeled, in the (a,β) coordinate frame, by a third-order nonlinear state-space representation. The control objective is twofold: (i) compensating for the current harmonics and the reactive power absorbed by the nonlinear load; (ii) regulating the inverter DC capacitor voltage. To this end, a nonlinear adaptive controller is developed, using the Backstepping design, on the basis of the averaged system model. The controller is made adaptive to compensate for the uncertainty that prevails on the unknown SAPF switching loss power. The average performances of the adaptive controller are formally analyzed using system averaging theory. The theoretical results are confirmed by numerical simulations.

Current Control Scheme for Three-Phase Power Quality Conditioner Under Balanced and Unbalanced Condition

The three-phase shunt active power filter eliminates harmonic currents and compensates reactive power for non-linear loads. A current control scheme based on the time-domain approach for three-phase shunt active power filters is analysed in this paper. A basic outline and evaluation of the performance of existing current control methods for active power filters are presented. According to different complicated power quality issues and various compensation requirements, a current control scheme based on time domain approach is proposed. Comparing with existing methods this algorithm has very short response time delay. Different compensation current references can thus be accurately and easily obtained by adopting the proposed current control scheme. The simulation results show the excellent performance and effectiveness of the proposed method.

Parameters Optimization Design of Four-Switch Three-Phase Shunt Active Power Filter

The working capability and cost of four-switch three-phase (FSTP) shunt active power filter (APF) are determined by the parameter selection. Based on mathematical model of FSTP inverter, the effect of key parameters, such as dc-bus voltage level and capacitor voltage transform is analyzed. On account of ac output filter inductance, voltage and capacitance on dc side, output filter in the design of four-switch three-phase APF, this paper expounds the optimal selection approach of parameters, sets up simulation model in PSIM, correctness of the method is verified by simulation on the basis of analysis about law of effect.

Three Phase Active Conditioner for Harmonics Mititgation

The Shunt Active Power Filter is a very essential tool to remove harmonic currents and to reimburse reactive power for nonlinear loads. The fundamental standard of process of a Shunt Active Power Filter is to introduce an appropriate non-sinusoidal current (compensating current) into the system at the point of common coupling. This research work focuses on the time-domain approach for three-phase Shunt Active Power Filters through an effective algorithm. A fundamental outline and evaluation of the performance of existing improved algorithms for active power filters are presented. An enhanced approach based on time domain technique is proposed based on various complicated power quality problems and various compensation functions. It is observed that the proposed algorithm provides has shorter response time delay when compared with the conventional approaches. Therefore, the proposed approach can accurately attain various compensating current references.

A Digital Signal Processor Based Performance Evaluation of Three-phase Four-wire Shunt Active Filter for Harmonic Elimination, Reactive Power Compensation, and Balancing of Non-linear Loads under Non-ideal Mains Voltages

Shunt active power filters are the most viable solution for solving current harmonic, reactive power compensation, and load unbalancing problems widely presented in electrical distribution systems. In this article, development and implementation of a digital signal processor based three-phase four-wire shunt active power filter are analyzed to compensate non-linear and unbalanced loads under non-ideal supply voltages conditions. The proposed algorithm is divided into two parts, the first associated with the calculation of the positive-sequence component of unbalanced supply voltage and second deriving a simple and attractive fundamental extraction filter to extract the fundamental frequency component from distorted positive-sequence voltage. Average power and DC-link energy balance methods are used to calculate peak value of the supply current, which is required to flow from source to load. The behavior and effectiveness of the proposed control algorithm has been verified by simulation using MATLAB/Simulink (The MathWorks, Natick, Massachusetts, USA) environment for different cases of supply voltage. A laboratory prototype has been developed to verify the simulation results. The control scheme is realized using a TMS320F28335 floating-point digital signal processor (Texas Instruments, Dallas, Texas, USA) based system. It is found that simulated and experimental harmonic spectral performances are in compliance with the recommendations about harmonic limits imposed by the IEEE-519 Standard.

Evaluation and Implementation of a Shunt Active Power Filter under balanced Source Voltages

The Shunt Active Power Filter has proved to be a useful device to eliminate harmonic currents and to compensate reactive power for nonlinear loads. The basic principle of operation of a Shunt Active Power Filter is to inject a suitable non-sinusoidal current (compensating current) into the system at the point of common coupling. An current control algorithm based on the time-domain approach for three-phase Shunt Active Power Filters is analyzed in this paper. A basic overview and evaluation of the performance of existing algorithms for active power filters are presented. According to different complicated power quality issues and various compensation purposes, a current control scheme based on time domain approach is proposed. Comparing with existing algorithms; this algorithm has shorter response time delay. Different compensating current references can thus, be accurately and easily obtained by adopting the proposed algorithm. Simulation results using MATLAB / Simulink have proven excellent performance of the proposed system and it is more effective than the available approaches.

Sliding-mode Control Based Three-phase Shunt Active Power Filter: Simulation and Experimentation

This article presents a simulation and experimental study of a sliding-mode controller of the DC bus voltage of a three-phase shunt active power filter. The sliding-mode controller is introduced to improve tracking performance characteristics, power quality, and minimized consumption of the reactive power. The algorithm used to identify the reference currents is based on the self-tuning filter. The firing pulses of the insulated-gate bipolar transistor inverter are generated using a hysteresis current controller, which is implemented on an analog card. Finally, this study, under steady-state and transient conditions, is illustrated with signal-flow graphs and corresponding analysis. This study was verified by both time-domain computer simulations and experimental tests on a hardware prototype based on dSPACE-1104 (dSPACE, Germany). The experimental results show the feasibility and the effectiveness of the designed active filter associated with a sliding-mode controller and its capability in meeting the IEEE 519-1992 recommended harmonic standard limits.

A novel digital control strategy of three-phase shunt active power filter under non-ideal mains voltages

A novel control strategy for three-phase shunt active power filter (SAPF) was proposed to improve its performance under non-ideal mains voltages. The approach was inspired by our finding that the classic instantaneous reactive power theory based algorithm was unsatisfactory in terms of isolating positive sequence fundamental active components exactly under non-ideal mains voltages. So, a modified ip-iq reference current calculation method was presented. With usage of the new method, not only the positive sequence but also the fundamental active current components can be accurately isolated from load current. A deadbeat closed-loop control model is built in order to eliminate both delay error and tracking error between reference voltages and compensation voltages under unbalanced and distorted mains voltages. Computer simulation results show that the proposed strategy is effective with better tracking ability and lower total harmonic distortion (THD). The strategy is also applied to a 10 kV substation with a local electrolysis manganese plant injecting a large amount of harmonics into the power system, and is proved to be more practical and efficient.

Improvement of Power Quality Using Optimized Non-Linear SAPF Controller

In this paper, the optimized Fuzzy Logic controlled three-phase Shunt Active Power Filters (SAPF) to eliminate harmonics of line current, correct power factor, balanced and unbalanced loads are given. To efficiently operate the system, Ant Colony Algorithm (ACA) optimizes this fuzzy logic controller. The controller is customized by adding a tuning controller to improve filter performance for lighter loads, in- addition, this tuning controller controls the output parameter of Shunt Active Power Filter (SAPF) by tuned to an optimized value. This optimized SAPF system has very short response time delay for different complex power quality issues and various compensation purposes. The system obtains dissimilar compensating current references accurately and easily. Moreover, Simulation shows that installation of this optimized controller in the SAPF system eliminates harmonics and corrects the waveform of the line current and corrected power factor. Simulation results obtained with MATLAB and testing results on a shunt APF are presented to validate the performance of the compensation system.