A Phase-Shift Full-Bridge Converter with Novel Voltage Oscillation Clamping Circuit for Electric Vehicle on-Board Charger

In this paper, a novel clamping circuit is proposed to solve the voltage oscillation problem of the phase-shift full-bridge converter for electric vehicle on-board charger. The proposed clamping circuit, consist of a single capacitor, suppresses the voltage oscillation of the secondary diodes. Besides, this clamping circuit can reduced output filter because it applies the voltage to the output inductor even in the freewheeling period. Therefore, the proposed converter can achieve high efficiency by utilizing the higher performance diode and achieve high power density by the simple clamping circuit and reduced output filter. In the proposed clamping circuit, the amount of voltage oscillation reduction is determined by the ratio of the leakage inductors. Thus, in this paper, the design guideline of leakage inductances is also provided. The feasibility of the proposed converter has been verified with the experimental results under 270–420 VDC output voltage range at 3.3kW.