Soft switching DC/DC converter with five resonant tanks for medium voltage applications

A zero-voltage switching (ZVS) converter with five resonant circuits with shared switches is presented to achieve the functions of less switch counts, low switching losses and low current stress of passive components at low-voltage side. For medium input voltage case, four split capacitors and four active switches with V_in/2 voltage stress are adopted at high-voltage side. Two balance capacitors are used to automatically balance input capacitor voltages in every switching cycle. Five resonant circuits are adopted in the proposed converter to share load current and reduce the current stress of passive components. On the basis of the circuit characteristics of resonant converter, power switches are turned on at ZVS from zero to full load. Rectifier diodes can be turned off at zero-current switching if the switching frequency is less than the series resonant frequency. Hence, the reverse recovery losses on the rectifier diodes are improved. Experimental verifications with a 1.92 kW prototype are provided to demonstrate the effectiveness of the proposed converter.