Study On Three-phase Hybrid Series Active Filter

With the development of power electronics and the wide application of power electronics equipments, non-linear loads bring the serious harmonic contamination, which draws attention all over the world. In order to improve the power network quality, many kinds of compensators have been developed. At present, passive filter (PF) is always applied in the high voltage and large capacity conditions. But PF can not adjust to the changeful order harmonics and the filtering effect is easy to be influenced by the power system reactance.As an effective way to correct power harmonic,active power filter (APF) can track and compensate any harmonic that is variable in frequency and amplitude. Otherwise, network impedance has no effect on the compensative result. Therefore, APF becomes the important trend to restrain power harmonic. At present, the application and development of that of shunt APF is outstanding. While,development of series APF is much slower than shunt APF. However, because of circuit structure characteristic of series APF, let it have an advantage over shunt APF on restraining voltage type harmonic source.This paper describes three-phase hybrid series APF's principle, harmonic detection, compensating current control and total circuit design.The mode of compensating voltage control determine the compensating effect. This paper introduces delay-cycle controlled PWM method for its high current tracking speed. The effect of control parameters on compensating results and the requirements to power electronic devices are derived in theory.In this paper, simulink software of Matlab is used to examine the design methord.The result show that this design has expectable compensating effect.