Techniques for subharmonics oscillations elimination in novel average-current-mode control of the constant frequency power converters

Abstract

This paper presents a stability analysis of a recently proposed average-current-mode control scheme for constant frequency power converters. In order to assess system stability considerations, a small signal model of the proposed control circuit is developed. The model is valid for power converters operating in the continuous conduction mode and is accurate up to half of the switching frequency. Two methods for eliminating subharmonic oscillations are also presented. The proposed control circuit is suitable for all applications where the average inductor current needs to be controlled-power factor correction circuits, battery charger/dischargers, etc. Model predictions are well confirmed through the simulation results.