Study of an optimized resonant converter for high-voltage applications

This paper presents the study of a high-voltage DC-to-DC resonant power converter which has excellent behaviour for use in applications with strong variations in the output voltage and in the output current, because it maintains high efficiency in these types of applications. To do so, the switching losses have been minimized by integrating all parasitic elements (leakage inductance, secondary side capacitance of the high-voltage transformer and parasitic capacitances of the power switches and diodes) into the power topology, and the conduction losses have been minimized by operating the converter in a special mode (optimum switching line) in which no reactive energy is returned from the resonant elements to the input voltage source. The type of control used (PWM phase-shifted) allows one to maintain these desirable characteristics even when the operating point suffers a very strong variation, The final power topology might be called a “full-bridge, clamped mode, LCC-type parallel resonant power converter with capacitive output filter”