Polar Fault Characteristics Analysis and Protection Scheme of Microgrid Interconnected in the Platform Area

With the wide application of microgrids, the interconnection between stations and areas has become an important means to improve the reliability of power supply. However, microgrid polar faults pose a threat to the stable operation of microgrids. In this paper, the polar faults of the microgrid are analyzed for equivalent modeling, and a microgrid model considering the interconnection of stations is established. Simulation analysis is carried out on the single-pole grounding fault, bipolar grounding fault, and three-pole grounding fault of the microgrid. According to the characteristics of current and voltage changes, a differential protection strategy based on the different current values at both ends is proposed. It can quickly isolate the fault area and reduce the impact of the fault on the microgrid. The protection scheme proposed in this paper provides an effective fault response method for the microgrid interconnected by the stations and helps to improve the power supply quality and stability of the microgrid. The correctness of the fault characteristics of the ring microgrid and the practicability of differential protection are verified by the MATLAB/Simulink simulation platform.