A 400kHz Current-Fed Bi-directional DC-DC Converter with Coupling Inductor

Energy storage devices are usually used to improve the power quality and reliability of the power supply system. A 400kHz current-fed bi-directional DC-DC converter adopting coupling inductor is investigated. The converter can achieve ZVS at full range of loads with high efficiency and the ripple current of inductor at low voltage side is small. The operation principle and control strategy are summarized. The working and coupling mode of the inductor at battery side is analyzed in detail. The problems encountered in the process of increasing switching frequency of the converter are analyzed and the corresponding solutions are given. A prototype of 1kW/400kHz bi-directional DC-DC converter is developed, and the theoretical analysis is validated by the experimental results.