The partial series resonant converter: a new zero voltage switching converter with good light load efficiency

A novel high-frequency DC-to-DC power converter, suitable for application in the kW range, is presented. The topology is series resonant for a part of each switching cycle and transfers a discrete energy pulse to the load every half cycle, rendering a variable-frequency controller for controlling the output power. The transformer is a pulse transformer which operates only during resonance, i.e., for part of each switching cycle, irrespective of the switching frequency. The converter features zero-voltage turn-on and snubbed turn-off at reduced current for the switching devices, and zero current commutation of the rectifier devices, making it suitable for IGBT (insulated-gate bipolar transistor) switches operating at a switching frequency higher than 20 kHz. Therefore, the efficiency of the converter is very high under full load and low load conditions, while the dynamic output voltage range is two times larger than that of the conventional series resonant converter.<
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