Operation of Combined HF and LF Boost Stage Inductors in PFC Design

Abstract

This paper presents an alternative solution on boost stage inductor design. The presented alternative inductor solution is to use an addition LC circuit to parallel with an original converter inductor so that it results an effective converter inductor. High frequency and low frequency current components in a traditional boost stage inductor can be separated out individually. The inductor in LC circuit guides the high frequency current components and the original inductor only needs to handle the line frequency current component. Therefore, each inductor can be more specifically focused on their target frequency component to be the optimization. Thus, a more effective converter solution is resulted under the combined inductor solution. In this paper, a detail design criteria is presented and together with a comparison with different magnetic components is provided. The performance of the presented solution is experimentally verified in a 300W test platform. Both steady state and transient state experimental results also show with a good agreement with the theoretical findings.