Power Flow Calculation of Multi-voltage Level DC Microgrid Based on DAB

The DC transformer based on Dual Active Bridge (DAB) converter has significant advantages and has broad application prospects in future multi voltage level DC distribution networks. Current research lacks power flow model and equivalent circuit models for DC transformers. Firstly, the steady-state mathematical model of DAB's DC transformer was derived. Secondly, the π - type equivalent circuit model was derived, and based on this, a method for model equivalence was proposed, which can quickly and accurately calculate the power flow of multi voltage level DC distribution networks containing multiple DC transformers, greatly reducing the time for power flow solving. Finally, the correctness and effectiveness of the proposed model and method were verified using the modified IEEE 14 node DC distribution network.