Research on a Novel Three-Phase Single-Stage Boost DCM PFC Topology and the Dead Zone of its Input Current

A novel three-phase single-stage boost power factor correction (PFC) converter topology is presented. The converter operates in discontinuous conduction mode (DCM), and the PFC function is realized easily with the peak of input current following input voltage automatically which is the same as that of the traditional single switch three-phase boost PFC. Compared with the single switch three-phase PFC, it can realize electrical isolation between input and output sides, output DC voltage regulation and achieve zero-voltage-switching (ZVS) for the leading-leg switches, zero-current-switching (ZCS) for the lagging-leg switches. Due to the existing of on state voltage drop of the switches and diodes, there will be a dead zone of the input current when its voltage is lower than the voltage drop of the charging circuit which will be more serious as the input voltage decreases. The input current dead zone is analyzed in details, and a compensating circuit is proposed which is verified through experimental results.