Digital Modeling and Optimal Design Tool for DAB Converter: A Case Study on Efficiency Improvement by Control Strategies and Power Semiconductors

Optimal design of power electronic converters requires extensive simulations, data collection, and performance comparison under various configurations of operating parameters, power devices, and control strategies. To improve design efficiency, an optimal design tool (ODT) for dual-active-bridge (DAB) converters is developed based on an explicit digital model and an optimal operating framework, which provides accurate performance prediction and fast optimization determination. The circuit-power model and loss-thermal model are integrated into the ODT with a generic closed-loop control structure. Therefore, the major performance indicators of the DAB converter, including dynamic and steady-state voltage and current waveforms, power losses of power semiconductors and passive components, and junction temperature, can be predicted by the proposed ODT. The evaluation results support efficiency/reliability-oriented design. Based on the ODT, a case study for efficiency improvement in terms of power semiconductors and control strategies is demonstrated. A database of qualified power devices and various control strategies is established, and the efficiency prediction under all potential combinations is executed with a tailor-made automated configuration-sweeping method. This enables comprehensive performance assessment and fast identification of the loss-minimizing configuration without manual adjustment of device models or control schemes. Thus, design efficiency can be improved especially when a large number of power semiconductors and modulation strategies are under evaluation. Simulation and experimental results confirm that the proposed ODT achieves both high accuracy and fast execution.