Wide load range three-level ZVS-PWM DC-to-DC converter

A new three-level ZVS-PWM DC-DC converter operating in a wide load range is introduced. It is used for high-voltage and high-power applications and has as its main features: zero-voltage-switching (ZVS) from no load up to full load, operation at constant frequency, regulation by pulse-width modulation (PWM), and low RMS current stress upon power switches. Its greatest attribute is that the voltage across the switches is half the value of the input voltage. A prototype operating at 100 kHz, rated at 600 V input voltage, 1.5 kW output power, and 25 A output current, has been fabricated and successfully tested in the laboratory. The principle of operation, theoretical analysis, design procedure, and an example, along with experimental results, are presented