A half-bridge zero-voltage switching pulse-width modulated DC-to-DC converter

The authors introduce a half-bridge DC-to-DC converter, regulated by pulsewidth modulation (PWM) at constant switching frequency and featuring commutation at zero-voltage. The principle of operation, the theoretical analysis, the design procedure and an example, and experimental results are provided. It is demonstrated that the proposed converter does not use resonance to transfer power to the load. The devices are not submitted to voltage stresses. The device is driven as a conventional PWM converter. It is suitable for low DC-voltage conversion ratio applications, as long as an isolating transformer is not employed. Two laboratory prototypes, one with isolated output and another with unisolated output, have been successfully implemented. The isolated prototype worked with an input voltage of 300 V, a switching frequency of 100 kHz, and output power of 550 W, and gave an efficiency of 82.5%