Intrinsic DC‐Bias‐Free Control for Dual Active Bridge DC‐DC Converters Based on Zero Initial Current Switching Sequence Construction

ABSTRACT The dual active bridge (DAB) converter is an important interface in power conversion for modern power systems, and it is essential to ensure its efficient and reliable operation. In conventional phase shift control, the change in transmission power is not intuitive, and transient dc bias is inevitable, which leads to complex mathematical calculations and additional dc bias control. To address this, an intrinsic dc‐bias‐free control framework is proposed in this paper. Based on the variations in inductor energy and power transmission characteristics, the durations of different inductor voltages are utilized to control power transmission, making transmission power variation more intuitive and physically insightful. Efficient switching sequences with inherently zero initial currents are constructed, and the closed‐form solutions can be simply derived. The proposed control strategy achieves low computational burden and simple gating logic, inherently avoiding transient dc bias and without duty cycle loss. It can realize full‐range power transmission with seamless switching sequence transition. Finally, experimental results confirm the feasibility of the proposed control strategy.