Voltage Disturbance Observation Method Based on Dual Active Bridge Converter Loss Model

The Dual Active Bridge (DAB) DC-DC converter has garnered widespread attention in fields such as electric vehicle power supplies, charging piles, and smart grids due to its advantages of bidirectional energy flow, high power density, ease of implementing soft-switching characteristics, and high efficiency. Research on DAB mainly focuses on two aspects: modulation methods and optimized control. By adjusting operational parameters such as the DAB’s return power, effective value of inductor current, and current stress, the goals of reducing losses and improving efficiency are achieved. However, due to model errors and nonlinear characteristics, the theoretically calculated optimal operating mode may deviate from the actual situation, necessitating the use of a closed-loop mechanism for correction. This paper directly addresses the control object of power loss in DAB converters composed of Gallium Nitride (GaN), proposing a loss model that is more direct and concise compared to traditional loss models. Through simulation verification, the input voltage value is locked using the voltage disturbance observation method, and the significance and value of the loss model are demonstrated.