Efficiency-oriented circuit parameter optimization of dual active bridge converter

Abstract

The power carbon neutrality path is to build a new power system with new energy as the main body. Dual active bridge (DAB) converter is considered as the core topology of new power system mode due to its galvanic isolation, bi-directional power capability, and wide soft-switching range, which is responsible for inter-connection between DC buses of different voltage levels and various DC loads. However, the lack of fast and accurate quantitative circuit parameter optimization design methods in DAB converter affects the improvement of the full working domain efficiency. In this paper, a hierarchical filtering method considering the control parameter is proposed to avoid the full range exhaustive search, and the effectiveness and correctness of the method are verified experimentally. First layer circuit characteristics must fulfill output power and inductor current requirements. The second layer filters poor inductor RMS current and soft-switching parameters. The last layer filters out weak steady-state circuit characteristics and identifies optimal regions. The proposed method improves the efficiency while reducing the area of the circuit parameter region for calculating the loss function by 85% compared with the traditional full-scale search method based on the loss analysis model, thus improving the optimization speed. The optimal circuit parameter solving process provides a graphical representation of the relationship between DAB operating characteristics and the optimal parameter area, ensuring proper optimization. Besides, the idea of hierarchical filtering can be well applied to the optimal design of other converters, and better guide the industrialization of products. • Using hierarchical filtering method can speed up the design. • Visualization of parameters can ensure the correctness of optimization results. • The design of other converters can also use the hierarchical filtering method. • Optimal design of parameters can ensure the normal operation of the device and also improve the steady-state characteristics.