A constant frequency parallel tuned resonant DC/DC converter for high voltage applications

A constant-frequency resonant DC/DC power convertor topology for use in high-voltage, high-power systems with ultralow output voltage ripple requirement is presented. Possible modes of operation are described and an efficient mode of operation is selected. Steady-state analysis of the converter is given, and performance curves are presented. A generalized curve describing the region of zero voltage switching is given. Experimental results for a prototype converter operating at 128 kHz and delivering 55 V, 28 A DC from a nominal 375 V DC bus are presented. They show an overall efficiency between 96% and 93% from full load to half load, and an output voltage ripple of less than 0.1%.<>