Abstract:
In this paper, the transient process of DAB under output short-circuit fault was analyzed in detail. Firstly, as the transient process analysis of the internal circuit was the main content, the time domain method and the decoupling method were used to derive the expression of the transient value of the internal current under different short-circuit situations; meanwhile, the transient expressions of output voltage and output current had been derived. The worst-case overcurrent conditions after short-circuit fault was obtained and the devices that are exposed to the greatest risk of overcurrent had been found. Based on the analysis results of the transient process, this paper proposed a method that adding a series inductor at the output to achieve fault ride-through; the range of the inductance to provide fault current feature while ensuring the safety of the internal circuit is derived. Based on MATLAB/Simulink, a 50kW DAB was simulated, and a 500W experimental prototype is built to complete the experimental verification. Simulation and experimental results verifies the correctness of the analysis results and the proposed method.