Study On Three-phase Three-wire And Three-phase Four-wire System Type Shunt Active Power Filter

Active power device (APF) is widely used in distribution network of industry,agriculture and business, aiming to purify power grid. This paper focuses its attentionon shunt active power filter (SAPF), conducting research on the whole system ofthree-phase three-wire and three-phase four-wire SAPF deeply.The paper introduces the system component of SAPF and its application inthree-phase three-wire and three-phase four-wire system firstly. After going deep intothe structure of main circuit, we choose three-phase four-leg structure as the maincircuit structure of three-phase four-wire SAPF.Through the comparison and analysis on the two most important links—harmonic current detection methods and current control strategies in detail, chooseip-iqharmonic current detection method and timer comparison control mode to buildSAPF system of this research. Then improve the low pass filter link of harmoniccurrent detection link.On that basis, calculate parameters of main electric components in the100kVASAPF system. Use MATLAB to build simulation model of three-phase three-wireand three-phase four-wire system, and analysis the compensation results underdifferent source and load. The simulation results verify the correctness of the system.Finally, it uses DSP TMS320F2812as its main control chip of the whole system,and designs hardware circuit of the2kVA prototype. According to the system, drawthe software flow diagram of this system, acheive the digitalisasation of the wholesystem. Through hardware and software debugging of the whole system, it showsthat the debugging results fit the simulation results. By the experiment result, we canfind that the APF has good harmonic compensation performance.