A New Soft Switching Current fed DC-DC Converter for Medium Power Applications

In this paper a new zero voltage switching current fed half bridge converter with an auxiliary circuit is proposed. The auxiliary circuit not only absorbs the voltage surge across switches at turn off instance, but also provides zero voltage switching condition for all converter switches. Therefore in this converter the efficiency is higher than hard switching counterpart and also main switches voltage stresses decrease. Since the switches in auxiliary circuit operate under soft switching conditions, these switches don’t apply additional losses to proposed converter. Implementation of control circuit is very simple since the converter is PWM controlled and the auxiliary switches turn on are complementary with respect to main switches. In this paper the proposed converter operating modes are analyzed and simulation results are presented. To verify the converter operation a ۱۰۰W laboratory prototype operating at ۱۰۰kHz is implemented and the experimental results are presented.