Near unity input displacement factor for current source PWM drives

A simple control scheme for near unity input displacement factor (IDF) operation of the three phase current source type PWM rectifier is proposed. The rectifier is operated by a conventional selective harmonic elimination pattern with 420 Hz switching frequency, which is feasible for GTO switches used in high power applications. The article includes a description of the proposed control scheme, IDF compensation limitations based on power circuit components, and simulation results for steady state and transient conditions. We also investigate the IDF values for PWM CSRs with various control strategies supplying CSI based AC drives with different types of industrial loads. Based on the results presented, a power factor correction scheme may not be necessary for a CSR-CSI AC drive supplying a particular type of load. Experimental results on a 10 kVA GTO PWM rectifier are included to confirm the feasibility of the proposed scheme for high power applications.