Location and Protection method of Single-phase ground fault in Low-voltage Microgrid

The low-voltage microgrid adopts a neutral point directly ground formula. For security, the low-voltage micro-grid single-connected ground failure needs to be isolated immediately. In the face of single-phase and high-resistance grounds, the two-way trend of low-voltage microgrids and operations from the network will cause difficulties in the protection of microgrid lists. In order to solve this problem, this article studies the single-phase grounding fault protection of low-voltage micro-power grids question. Aiming at the characteristics of many distributed power supply equipment in the microgrid, the simplified chart and the directional model of the microgrid were established. The remaining current of the phase line and the neutral line is not zero as a starting judgment of a single-phase and high-resistance ground failure, and then proposed the remaining current protection method of the direction, and its protection positioning algorithm was established based on the microgrid diagram model. Based on the residual current protection of the direction, a network-based microgrid listing protection system is established, and the implementation process is described. Finally, the effectiveness of the fault protection of the network of the micro-power grid is verified by simulation.