Multi-function zero-voltage and zero-current switching phase shift modulation converter using a cycloconverter with bi-directional switches

A novel voltage source full-bridge DC-DC converter with phase shift modulation using a high-frequency cycloconverter is proposed. Both zero-voltage and zero-current switching (ZVZCS) commutation for full-bridge active power switches and zero-voltage switching operation for cycloconverter bi-directional switches are obtained. Soft switching operation is provided in a wide range of voltage regulation without utilising an auxiliary inductor in the primary side of an isolating transformer. To implement this DC-DC converter as a multi-function DC-AC inverter, a reference signal is traced by the control system to adjust the output voltage according to the variations of the reference signal. Therefore desired output waveforms are provided by selected reference signals. Hence the proposed circuit operates as a multi-function converter. Based on the simulation and experimental results, the steady-state operation principles of the converter are analysed and discussed. Experimental results from a 24 V-DC input and 20 kHz fixed switching frequency laboratory prototype is presented to introduce both the switching operation and the multi-function performance of the converter.