A Risk Assessment Method of Intelligent Substation Relay Protection Device Based on Severity Index

This paper studies the risk assessment method of the relay protection device of the intelligent substation line, and comprehensively considers the fault probability of the relay protection device and the influence of the fault on the power system. Firstly, this paper determines the five states of the relay protection device by analyzing the message of the Network analyzer, and calculates the reliability data by Markov state space model. In the next section, with Monte Carlo simulation, the paper calculates three single electrical severity indexes, including voltage limit severity, component overload severity and load loss severity. Finally, based on AHP and variation coefficient method, this paper calculates the weights of each index and the ultimate risk of the protection device. IEEE - 30 system verifies that risk assessment method of intelligent substation relay protection device based on severity index is feasible. It can determine the risk level and importance degree in the system of each system component, providing a certain reference for power system operation maintenance personnel. It can analyze and summarize the importance of each relay protection device in the system, providing a certain reference for power system operation maintenance personnel.