Constant Frequency ZVS PWM Converter

In this paper, a simple yet novel buck or boost adaptive zero-voltage switching (ZVS) converter topology is proposed for soft switching pulse-width modulation (PWM) dc / dc converters. The converter is designed for the high switching frequency that can achieve high efficiency by reducing switching losses for the entire load range at low and high power. Besides, the output at the load terminals is maintained by a PWM signal at a fixed switching frequency, a phase shift signal between converter ports (legs) controls the system circulating current in order to provide the ZVS condition in all load conditions. With the proposed controller, the converter, thus, is suitable for high switching frequency and high-power applications with the small volume. The proposed dc / dc converter operation is analyzed, designed, and confirmed by simulation results for 240 V input, 400 V / 5 A output, and 200 kHz operating frequency at full load.