An Expandable High Voltage-Gain Resonant DC-DC Converter With Low Semiconductor Voltage Stress

A high voltage-gain resonant DC-DC converter is proposed in this brief, where a coupled-inductor with multiple windings is adopted. The proposed converter is composed of a boost unit with input-output in series connection and z(z > 1) expandable units. Each expandable unit includes two secondary windings of the coupled-inductor and two leakage-inductor-resonant-capacitor cells. The secondary windings are helpful to get a high voltage-gain, while the resonant cells are helpful to realize zero-current-switching for all diodes. Moreover, all the semiconductors can be thought as in series connection, leading the voltage stresses much lower than the output voltage, especially that of the switches. A laboratory prototype with two expandable units is built to verify the proposed converter.