A subharmonic stability of power factor correctors with dual-loop control system

Abstract

This work is devoted to investigation of the power factor corrector's (PFC) dual-loop control systems. Two control systems of PFC with different structures were studied: with main voltage and main current feedbacks. A subharmonic stability analysis has been performed for PFC based on conventional boost converter. However, the expression for input current of the storage inductor can be used for PFC based on zero-current switching quasi-resonant boost converter. The stability condition at the main subharmonic frequency has been formulated. The calculation results of the voltage change rate at the current loop input and factor of pulsations have been presented. The PFC subharmonic stability margin has been assessed and condition for choosing the reference voltage amplitude has been proposed.