Research on Grounding Methods of DC Microgrid Based on Power Supply Connectivity and Reliability

With the rapid development of distributed energy, DC loads, variable frequency loads and voltage sensitive loads, DC microgrids will be widely used in future power grids. At this stage, there is no uniform standard for the grounding design of the DC microgrid, and the grounding methods used in various domestic demonstration projects are also different. Aiming at the DC microgrid based on two-level voltage source converter, this paper analyzes the pros and cons of various grounding methods from the perspective of power supply continuity and reliability. It is recommended to use TT grounding for occasions with high power supply reliability requirements. The selection of the grounding method in the actual project needs to consider many factors. Therefore, the conclusion of this article cannot be used as the judgment standard of the DC microgrid grounding design, but it can provide a certain reference for the designer.