An Improved ZVZCS Full Bridge Converter with secondary Resonance for High Power Applications

摘要

A new zero voltage and zero currentswitching (ZV ZCS) full bridge (FB) PWM converter is proposed to improve the performance of the previously presented ZVZC S-FB-PWM converters. In the proposed circuit leakage inductance of the transformer is utilized as secondary resonance with out an additional inductance. The ZV ZCS means mixed operation of zero -voltage switching (ZVS) for leading-leg switches and zero-current sw itching (ZC S) for lagging-leg switches. The primary side of the converter is composed of FB insulated-gate bipolar transistors, w hich are driven by phase-shift control. The secondary side is composed of a resonant tank and a half-wave rectifier. Without an auxiliary circuit, zero-voltage sw itching (for leading-leg switches) and zero-current sw itching (for lagging-leg sw itches) are achieved in the entire operating range. These days, IGBTs are replacing MOSFETs for high voltage, high power applications, since IGBTs have higher voltage rating, higher power density, and lower cost compared to MOSFETs. The analysis and design co nsiderations of the proposed converter are presented