Abstract
A new buck-boost converter featuring clamping action, PWM modulation and soft-switching (ZVS) in both active and passive switches, is proposed to overcome the limitations of clamped mode buck-boost converter. The new converter is generated from an improved cell of ZVS-PWM active clamping dc-to-dc converters. As the resonant circuits absorb all parasitic reactances, including transistor output capacitance and diode junction capacitance, this converter is suitable for high-frequency operation. Principle of operation, of the new converter, theoretical analysis, simulation and experimental results are presented, taken from a laboratory prototype rated at 500 W, input voltage of 150 V, output voltage of 50 V, and operating at 100 kHz