Single phase parallel power processing scheme with input-shunt power factor correction stage

Abstract

A single-phase parallel power processing scheme with input-paralleled power factor correction stage is proposed. The input current in the proposed scheme is nearly-sinusoidal with power factor close to unity. This scheme is very attractive for systems with two or more independent loads, each requiring a ac-dc power converter. An example of one such system is a personal computer (the monitor and the CPU units). For such a system, the proposed scheme is both cost effective and efficient than the currently popular two-stage cascaded scheme. The scheme is implemented using a half-bride boost PFC stage, and is analyzed in detail. Analytical plots and expressions useful to a design engineer, have been developed. Switched and averaged model simulation results, and experimental results are also included. An efficiency of 93.78% at 90 V input, and a power factor of 0.999 were obtained experimentally. The possible circuit variations of the proposed scheme have also been identified.