Research On Harmonic Detection And Control Method Of Active Power Filter

Along with the development of power electronics technology, as well as improved requirement of power quality, harmonic suppression and reactive power compensation has got more attention. As a dynamic compensation equipment, active power filter has much larger advantages than other compensation methods. Compared with other kinds of APF, this paper chose three phase shunt APF to study and puts forward a design of shunt active power filter based on DSP control, with special attention on harmonic detection and control strategy.There are p-q method, ip-iq method based on instantaneous reactive power theory and dq0 method based on dq0 transformation to be study. Three methods calculation results were compared under different voltage circumstances with simulation. 30 bands finite digital filter was designed whitch dynamic response time is 6 mS at the sampling frequency of 5 kHz. Two current tracking control methods were discussed and fixed frequency hysteresis-loop comparator was chosen according the requirement of IGBT. DC voltage control method was studied in the two detecting method.A design of control system selecting DSP as the control core and its hardware design and software flow are introduced in detail. The results validate the method of reactive and harmonic current detection and control strategy in the dissertation, and also meet the design requirement of APF.