Development of isolated type DC/DC converter for on-board power supply

Abstract

A 20 kW high frequency DC/DC converter composed of two identical 10 kW units has been constructed for a hybrid vehicle application. Based on the requirement given, the Zero Voltage Switching Phase-Shifted Full Bridge topology has been selected and studied, from which analytical equations have been derived for the design of the 10 kW units. Special attention has been given to the zero voltage switching transitions and the deadtime of the converter. Furthermore, a loss analysis has been followed to guide the system component selection. The design of magnetic components has also been addressed, including an inductor design and a review of the design principles for a high-frequency transformer. A voltage control scheme has been implemented with a PI controller based on the converter small-signal model, and the converter functionality has been confirmed by simulations. Finally, a converter prototype has been assembled and experiments have been conducted. Keywords: Phase-Shifted Full Bridge converter, zero voltage switching, high frequency, deadtime