PWM zero-voltage switching single-ended current-fed converters with output isolation

A modified boost converter is proposed to accomplish power transfer to the load with electrical isolation, zero-voltage and zero-current switching, transformer core resetting mechanism, and identical component stresses as those in the conventional boost converters. Zero-voltage switching and proper transformer-core resetting are achieved from the resonance that exists between the parasitic capacitance of the switch and the magnetization inductance of the transformer. The transformer leakage inductances facilitate zero-current switching; thus, reducing the recovery time and current in the output rectifier, and the turn-on switching loss in the conventional main switching device. Introducing a lossless clamping circuit, the voltage stresses on the switching devices are limited to the reflected output voltage appearing across the primary.<
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