Research On Control Method Of Active Power Filter Based On Three-Phase Four-Wire System

The existence of harmonic and reactive power not only reduces the efficiency of electricity supply equipment, but also endanger the safety of the public power meshwork and interrupt the normal operation of the nearby equipment. The Active Power Filter (APF) is an effective way to compensate harmonics and reactive power. Based on three-phase four-wired system, this paper research the control method of the active power filter.The main contents of this paper are as follows:1, The status of the development and the sorts of active power filter, and its topology and characteristics are introduced. The basic working principle of parallel active power filter is analyzed also.2, This paper discuss the main circuit topology of the parallel active filter system on three-phase four-wire system, analysis its mathematical model, and probe into the main circuit parameters and capacitor voltage control method of DC-side also.3, The control method of active power filter is studied . The advantages and disadvantages of hysteresis Pulse Width Modulation(PWM), triangular wave PWM and three-dimensional space vector PWM technology are compared. The simulation model of the triangle-wave PWM and three-dimensional space vector PWM technology are carried out by MATLAB6.5/Simulink. The symmetric and asymmetric cases of the system are simulated separately. The results show that the accuracy of three-dimensional space vector PWM technique is better than triangle-wave PWM technique in the symmetrical & asymmetrical three-phase four-wire system.