A New Method of Distance Protection for High-Voltage Lines of Substation Accessed by Distributed Power Supply

When the AC line with distributed power supply accesses the power grid, the traditional distance protection cannot act correctly due to the influence of fault characteristics such as frequency offset of distributed power supply. Based on the frequency offset fault characteristics of distributed power supply, analyzing the characteristics of the electrical quantity at the AC line protection installation, and based on the adaptability analysis of distance protection based on phase quantity, a new method of distance protection for high-voltage lines is proposed. The analysis shows that the proposed distance protection method is suitable for AC line protection with distributed power supply access to the grid, and is applicable to the protection of the near-area fault situation. Simulation results show that the distance protection method has good protection performance and is not affected by fault location, fault type and other factors.