Analysis of the fault characteristics of DC microgrid and research on the parameter selection of current-limiting reactor

This paper analyzes and deduces fault voltage, current characteristics and response curves based on the topology and grounding method of DC microgrid. The constraints on the selection of the reactor were given considering factors such as equipment safety and protection cooperation in the event of a fault after analyzing and comparing the short-circuit conditions before and after loading reactor. The short-circuit conditions before and after loading reactor were analyzed and compared, and the constraints on the selection of the reactor were given considering factors such as equipment safety and protection cooperation in the event of a fault. A case simulation model of a DC micro-grid in a park was built and the typical fault points were selected for the two cases of adding or not adding a current-limiting reactor. It shows that adding a reactor can effectively reduce the short-circuit current and prolong the fault response time, which is conducive to fault monitoring and judgment and verifies that the fault characteristic analysis is correct. The reactor parameters obtained according to the reactor selection conditions proposed in this paper can meet the engineering requirements and can be used for practical engineering selection reference.