Full bridge converter with asymmetric duty cycle control for low common mode noise

Abstract

In this paper, a new full bridge converter with asymmetric duty cycle control for low common mode noise is proposed in order to achieve high power density. The conventional phase shifted full bridge converter has high common mode noise, which increases the size of the common mode filter inductor. The proposed converter uses a coupled inductor and an asymmetric duty cycle control to generate voltage variations of the transformer in the same direction. Through this, Common mode noise is reduced because voltage variations cancel each other out. As a result, the proposed converter can achieve high power density by reducing the size of the common mode filter inductor. The performance of the proposed converter is verified by the experimental results with a 56V/13.4A 750W prototype converter