Design of high voltage DC power supply using asymmetric three phase resonant

This paper describes the basic design of a 50 kW three phase converter with low ripple and high control accuracy. Based on three phase LCC-type series resonant converter (LCC-SRC) which has advantages of low ripple, relatively high-efficiency, and high-power density compare to single phase converter, the 50 kV, 1 A high voltage power supply with low ripple less than 0.1% is designed. In addition to general the merits of LCC-SRC operating at continuous conduction mode (CCM) including soft-switching, low conduction loss, and current source characteristic, the proposed scheme which uses only one phase at light-load condition by having different leg design of gate drive circuit and snubber parameter allows to overcome the operational constraint of general LCC-SRC. A distinctive design of three phase converter structure provides high-efficiency and low ripple not only rated operation but also light load condition. In order to analyze the high-performance of the proposed scheme from no-load to full-load, PSpice simulation was carried out. And comparison results with conventional LCC-SRC based on single phase structure are analyzed in view point of output ripple, IGBT losses, efficiency, and operable load range. Also, this paper deals with the designs of high voltage transformer and rectifier considering high voltage isolation. Finally, the superiority of the proposed converter is discussed in the following paper.