A novel soft-switching full-bridge DC/DC converter: Analysis, design considerations, and experimental results at 1.5 kW, 100 kHz

The authors present an improved soft-switching full-bridge converter which is especially suitable for high-power application (e.g. more than 1 kW output) because of its inherently high efficiency. The addition of an external commutating inductor and two clamp diodes to the phase-shifted PWM (pulse width modulation) full-bridge DC-DC converter substantially reduced the switching losses of the transistors and the rectifier diodes, under all loading conditions. The authors analyze the conditions for lossless transitions, discuss the effect of the added components on the operation of the converter, and present practical considerations and test results for a 1.5 kW converter with 100 kHz clock frequency. The converter has an efficiency above 95% at 60 V output, is free from voltage overshoots, and exhibits well-controlled transitions for all switch and rectifier voltages and currents.<>