Research On Shunt Active Power Filter In Three-Phase Four Wire System

With the development of electronic technology, the various nonlinearity and time-varying electronic devices are made to apply increasingly. First, power energy transformation is applied conveniently. Second, the harmonic and reactive power cause serious pollution for the power grid, the power system and user are caused great damage. Active power filter, which is a device simultaneously compensating harmonics and reactive power current, have been brought as more and more attention.Recently, the problems about harmonics and loads unbalance of three-phase four-wire power grid are more and more serious, so the research in harmonic and reactive current compensation in the three-phase four-wire system in this paper is proposed. The basic principle of harmonic and the working principle and the classification of active power filter are introduced, and detection algorithm which is based on instantaneous reactive power theory is described. Finally, improved ip-iq algorithm which applies three-phase four-wire system is put forward, several tracking control method of the dc capacitor and compensation current is described.Based on the theory research on shunt active power filter in three-phase four-wire system, the hardware and software is designed. with two DSP TMS320F2812 of TI company as the core, the design of signal sampling circuit, control circuit, IGBT driving and converter circuit and the design of main circuit parameters, shunt active power filter experiment device in three-phase four-wire system is designed. The system section function is tested in the laboratory.The result that is analyzed by MATLAB simulation experiment proves the good effect, and the feasibility of the method of detection and control is proved. Finally, the full work of the paper was summarized.