Research On A Novel Half-Bridge DC/DC Converter Using Secondary-Side Control

With the development of Power Electronics and the need of industry and life, the technology of Switching Mode Power Supply(SMPS) is gradually being perfect. Small and portable performance has become the trend of SMPS, which highly depend on switching frequency. Switching loss must be reduced in order to increase switching frequency and hence the efficiency. Soft-switching is then proposed to meet these demands. In medium and high power SMPS, phase shifting controlled ZVS PWM full-bridge converter (PS ZVS PWM FB converter)is one of most ideal way to implement power conversion, for its simple topology and control, as well as constant frequency. But in this converter, ZVS is difficult to be achieved for the lagging leg. In addition, primary current circulates through the switch during the entire freewheeling interval, contributing significant conduction losses.A Novel Half-Bridge DC/DC Converter Using Secondary-Side Control is proposed in this paper to improve the performance of PS ZVS PWM FB converter. In this converter, soft-switching is achieved from no-load to full load, in which ZVS is achieved for primary switches, and ZCS is achieved for secondary switches. The filter requirements are significantly reduced for the superior filter waveforms. The principle and characteristics of the proposed converter is analyzed, and verified on a 100W (12V/8.4A output) experimental prototype, and experimental results are presented.