Research Of Single Phase Active Power Filter

At present, the study of active power filter focused on three-phase APF at home and abroad, the study of single-phase APF is not deep and wide enough. With more and more using of single-phase power electronic equipment, the impact of Single-phase equipment to power grid is Increasingly prominent. The study of single-phase active power filter is becoming more and more important.This paper studies the single-phase parallel active power filters,and the experimental prototype is developed. The results of harmonic suppression is good.The article first established a single-phase mathematical model of APF,based on this model the main circuit parameters are designed and analyzed. The relationship of the parameters , such as DC side voltage, AC side inductor and so on , with filtering performance has been got quantitative .In the control, detection of harmonic,the control and PWM output mode are all analyzed systematically, the method of detection of harmonic currents based on theory of sliding-window discrete flourier transform and instantaneous reactive power have been compared, and their respective advantages and disadvantages are pointed out. The control strategies are analyzed, include the inner current loop controlled by PI and repetitive control and the outer voltage loop controlled by PI control. The digital control system is designed based on the control strategy; the technology of space vector modulation is introduced into single-phase system,point out that it is optimum and flexible. the analysis show that this control strategy has good steady-state accuracy and dynamic performance。Finally, a single-phase APF simulation and experimental have been done. Based on simulink in Matlab software, the correctness and feasibility of theoretical analysis is confirmed by the simulation results. The results of the experiment designed with TMS320F2812 show that the harmonic orders can be detected accurately by sliding-window discrete flourier transform; the PI control can not track the harmonic orders, but the dynamic performance is quick. The repetitive control can make up the shortage of ,steady-state accuracy. The good steady-state and dynamic performance is implement by using the tew kind of control method. A variety of methods to optimize the program of single-phase space vector modulation have been implemented, and the results are good.