输出短路故障下的DAB暂态过流分析

文章详细分析运行在双重移相下的双有源桥在输出短路故障下的暂态过程。分析过程采用时域分析法,并实现内部及外部电路的解耦。针对不同的模态,推导双有源桥在不同类型短路故障后,内部电流、输出电压和输出电流的暂态表达式,进而论证暂态过程中存在的过流现象,指出最严重的过流风险。基于暂态过程的分析结果,该文提出在输出端串联电感来实现双有源桥的短路故障穿越的方法,并推导了串联电感值的范围,使双有源桥在内部电路无过流风险的前提下,提供合适的短路故障特征。基于MATLAB/Simulink软件对50k W的双有源桥模型进行仿真,同时搭建500W的实验样机并完成实验验证。仿真及实验结果验证所提分析结果及方法的正确性。

Transient Overcurrent Analysis of Dual Active Bridges Under Short Circuits of Loads

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 50 k W DAB was simulated, and a 500 W experimental prototype is built to complete the experimental verification. Simulation and experimental results verifies the correctness of the analysis results and the proposed method.