High Efficiency Bi-Directional DC-DC Converter with Matrix Transformer Isolation for Heavy Duty Hybrid Electric Vehicles
Medium power DC-DC converter is an essential component in Hybrid Electric Vehicle (HEV) to achieve power transfer from High Voltage bus (HV) to Low Voltage bus (LV) and vice-versa. Dual Active Bridge (DAB) is among the most researched topology for medium and higher power converters with advantages such as bidirectional power transfer, high efficiency, high modularity, and high-power density. Multi-Objective Design Optimization with low converter loss and low converter volume as its objectives is used as a basis of parameters and components design. Integrated planar Matrix transformer is employed for galvanic isolation of the two voltage buses providing lower transformer losses compared to the traditional transformers. Peak Current mode control is implemented in DSP control card to ensure DC offset across the transformer is minimum as well as ensuring faster transient response in cascade with closed loop voltage control. The converter design is prototyped as a proof of concept, which can operate within a wide range of input voltages (400V-800V) and serves low-voltage high-current loads.