Optimal negative current control for four-phase interleaved bi-directional buck/boost converters to achieve ZVS and ZCS

This paper presents an optimal negative current control for four-phase interleaved bi-directional converters to achieve soft-switching features. Four-phase buck/boost converters with bi-directional operation and in discontinuous conduction mode (DCM) are designed and implemented. The optimal negative current is determined and controlled to reduce reactive power loss, while achieves ZVS and ZCS turn-on for the active switches in the bi-directional converters. Variable frequency and PWM control are also introduced to fit load requirements and insure the DCM operation. Simulation and experimental results obtained from a four-phase interleaved prototype have verified its performance and feasibility.