Multiphase Interleaved Bidirectional DC/DC Converter With Coupled Inductor for Electrified-Vehicle Applications

A nonisolated high-power-density bidirectional dc/dc converter named multiphase interleaved with a coupled inductor is described. The proposed converter allows low current and voltage ripple, lower power losses, reduction on power component stress, and magnetic volume. Moreover, the coupled inductor is applied to achieve current sharing between each leg in a simple manner, which is helpful to simplify the structure and meaningfully improve performance. Auxiliary clamp circuits are not required and can operate over a wide voltage and power range, achieve a better dynamic response and low ripple while maintaining high efficiency. This article illustrates the steady-state operating principle under the inductor current continuous, discontinuous conduction modes and their boundary conditions in detail, the voltage and current stress of the power devices are shown, parameter design guideline, mathematical derivations, and a comparison between the proposed converter and previous dc/dc converters were conducted. Finally, a 4.5-kW proof-of-concept laboratory prototype has been designed, developed, and tested to demonstrate the performance of the proposed converter for wide load variation. The measured efficiency for the rated load was over 98% for maximum input voltage. This article is accompanied by a video file demonstrating the operation of the converter.