Control for the Three-Phase Four-Wire Four-Leg APF Based on SVPWM and Average Current Method

Xiangshun Li,Jianghua Lu

doi:10.1155/2015/528360

Abstract

A novel control method is proposed for the three-phase four-wire four-leg active power filter (APF) to realize the accurate and real-time compensation of harmonic of power system, which combines space vector pulse width modulation (SVPWM) with triangle modulation strategy. Firstly, the basic principle of the APF is briefly described. Then the harmonic and reactive currents are derived by the instantaneous reactive power theory. Finally simulation and experiment are built to verify the validity and effectiveness of the proposed method. The simulation results show that the response time for compensation is about 0.025 sec and the total harmonic distortion (THD) of the source current of phaseAis reduced from 33.38% before compensation to 3.05% with APF.

Highlights

As the power electronic devices are extensively used in the industrial and commercial areas, a large number of nonlinear loads such as electrical machines, static power converters, and electric arc furnaces have been connected to the power system, which lead to waveforms distortion of voltage and current in the grid and seriously degrade the power quality [1,2,3]
References [8,9,10] analyse the three-dimensional space vector pulse width modulation (3D-SVPWM) control theory and introduce 3D-SVPWM strategies based on the αβγ coordinate systems or the abc coordinate systems to the threephase four-leg shunt Active power filter (APF)
This paper proposes a novel kind of control method based on the three-phase four-leg inverter for the shunt APF

Summary

Introduction

As the power electronic devices are extensively used in the industrial and commercial areas, a large number of nonlinear loads such as electrical machines, static power converters, and electric arc furnaces have been connected to the power system, which lead to waveforms distortion of voltage and current in the grid and seriously degrade the power quality [1,2,3]. References [8,9,10] analyse the three-dimensional space vector pulse width modulation (3D-SVPWM) control theory and introduce 3D-SVPWM strategies based on the αβγ coordinate systems or the abc coordinate systems to the threephase four-leg shunt APF. Though these strategies provide good ideas and measures to solve the zero-sequence current compensation, they come up with some shortcomings such as high complexity and slow speed in computing. This paper proposes a novel kind of control method based on the three-phase four-leg inverter for the shunt APF. Are the control theory and computation of this method very simple, which is based on the two dimensional SVPWM control algorithm and triangle

Working Principle

C Rd uSa uSb uSc i2k ia ib ic in Nonlinear load

Control Strategy of the Compensation

Simulation and Experimental Analysis

Conclusion

Conflict of Interests