A PARALLEL FEED-FORWARD COMPENSATING TYPE POWER FACTOR CORRECTION CIRCUIT FOR A THREE-PHASE POWER SOURCE

摘要

A parallel feed-forward compensation type three-phase power factor correction circuit for a three-phase power supply comprises a primary rectifying circuit I, and a feed-forward compensation circuit II which is in parallel with the primary rectifying circuit I. The primary bridge rectifier circuit I comprises a three-phase bridge and a filter capacitor. The feed-forward compensation circuit II comprises a plurality of bi-direction switches, a rectifying circuit, a boost converter, an output current sampler and a control circuit. In the corresponding phase interval the feed-forward compensation circuit sequentially closes the phase of that whose absolute value of the voltage is the higher one of the two phases at same polarity. The other two phases are rectified by bridge rectifying circuit and forced to export a compulsive current waveform. In this configuration, it can amend the current waveform of each phase, reduce harmonic distortion and improve the efficiency of the power supply with very little power.