A new separated resonant-inductor winding phase shift full bridge converter for server power system

Abstract

A new separated resonant-inductor winding (SRW) phase shift full bridge (PSFB) converter for the server power system is proposed in this paper. Since DC/DC converter of server power system is operated with high input voltage and large output current, zero voltage switching (ZVS) operation of the primary switches and low conduction loss of secondary rectifiers are essential to achieve high power density and high efficiency. As a result, among many topologies, PSFB converter with additional resonant inductor and clamping diodes, which can achieve ZVS operation and low voltage stress of secondary rectifiers, is widely used. However, since the high input voltage with small duty ratio is applied to the additional resonant inductor, high eddy current loss and excess eddy current loss are occurred on magnetic core. Therefore, bulky and high cost magnetic core is required for additional resonant inductor. To overcome this drawback, the proposed converter implements the additional resonant inductor and transformer using only one magnetic core. Therefore, size, cost and core loss of the additional resonant inductor can be reduced. Experimental results demonstrate that the proposed SRW PSFB converter can achieve high power density and high efficiency in a 1200W (12V, 100A) prototype converter.