SIMULATION AND ANALYSIS OF SINGLE PHASE SHUNT ACTIVE POWER FILTER

Because the active power filter can overcome such demerits of passive power filters as fixed compensation, large size and resonance, it is regarded as one of the equip- ment which can effectively improve power quality. From the viewpoint of practical application of active power filters, the authors perform simulation and analysis of active power filter in the following three aspects: the variation of system impedance, the startup of active power filter and the abrupt change of load current. Through the simulation and analysis of single phase shunt active power filter presented in this pa- per, the following results are obtained. (1) It has good ability to cope with the variation of system impedance, i. e., the harmonic compensation capability of the active power filter is insensitive to the system impedance. (2) The over current is bearable during the startup of the shunt active power filter. (3) The improved DC voltage PI regulation plays a good role in maintaining the voltage across the capacitor at DC side of the inverter with in a specified range. The improved dc volt- age PI controller displays better effect during the abrupt change of the load current. The obtained results are available for reference in designing active power filters.