Fully soft-switched half-bridge DC-DC converter for hybrid electric vehicle battery charge applications

This paper proposes a soft-switching (SS) active snubber cell for half-bridge (HB) DC-DC converters, which are utilized in hybrid vehicle battery charge applications. The proposed converter has an advantage over conventional HB DC-DC converters, which suffer from transformer leakage inductance issues. The new snubber cell performs SS operation using the energy stored in the leakage inductance. Thus, the leakage inductance, which creates troubles for HS DC-DC converters, is beneficial to the proposed converter. The proposed SS HB DC-DC converter is compared with the conventional HB DC-DC converter under 100 kHz and 110 W output power operating conditions. The efficiency of the proposed converter is 7.3% and 4.8% higher than the conventional HB converter at light and heavy loads, respectively. The proposed active snubber cell provides complete SS for the main and auxiliary semiconductor switches. The new snubber cell has a basic structure, low-cost, ease of application, and simple control features.