PV 시스템의 차동 전력 조절기 모듈용 양방향 플라이백 컨버터 설계 방법

Abstract

A bidirectional flyback converter is a suitable topology for use in a PV-to-bus diferential power procesing (DP) module for PV aplications due to its electrical isolation capabilty, bidirectional power transfer, high step-up ratio, and simple circuit structure. However, the bidirectional flyback converter design should consider the efect of the output-side power switch utilzed for bidirectional operation compared to the conventional flyback converter. This paper presents the structure and design methodology of the bidirectional flyback converter for a PV DP module. Magnetizing inductance is designed by calculating the power los of converter components within the rated load range under discontinuous conduction mode (DCM), which is not afected by the reverse recovery characteristics of the anti-paralel diode of the output-side power switch. The validity of the proposed design methodology is verifed using a 25-W bidirectional flyback converter prototype. Moreover, the operational principles and the performance of the DP operation are verifed using practical DP modules consisting of the bidirectional flyback converters implemented acording to the proposed design methodology.