스위치 전압 스트레스 감소를 위한 포워드 컨버터의 스너버 회로에 관한 연구

Abstract

In forward converters, the transformer has been widely used for the conversion of the voltage or electrical insulation. However, the transformer may cause two main problems. First, the transformer core needs to be reset to prevent the magnetizing current build-up and transformer saturation. Second, the transformer generates a voltage spike across the switch by the discharge of the leakage inductance, which can cause the switch over-voltage breakdown. Generally, engineers have been used snubber circuits to solve these problems. In this paper, the previous snubber circuits for the forward converters are investigated and an optimal transformer energy recovery circuit is proposed. This proposed circuit can reduce the switch voltage stress with a small snubber capacitor and tertiary winding. Experimental results are presented to confirm the validity of the proposed circuit.