Transient Modeling Method for Faulty DC Microgrid Considering Control Effect of DC/AC and DC/DC Converters

The accurate transient modeling of faulty DC microgrids is the basis of fault detection, fault location and fault isolation. AC/DC and DC/DC converters keeps their normal control strategies until the fault is detected. However, in existing researches, the influence of the control effect of converters is normally being ignored in the transient characteristics of DC microgrids. This omission reduces the accuracy of the faulty transient model. Thus, this paper proposes a transient modeling method for faulty DC microgrid considering control effect of different DC/AC and DC/DC converters. Firstly, the transient characteristics of different converters (including voltage source converter, boost circuit, bidirectional chopper circuit and buck circuit) are analyzed. And then, the faulty transient model of ring-type DC microgrid is established. Furthermore, the correctness of proposed modeling method is verified by comparing with the Control-hardware-in-loop (CHIL) test system. The results show that the proposed method can not only improve the accuracy of transient analysis of faulty DC microgrid, but also enhance the calculation efficiency.