Abstract: The increasing penetration of new energy into the power system is accompanied by a series of challenges that traditional relay protection systems face: fast fault detection and decreased protection action time, and decreased system stability. able sources such as wind and solar. As technology advances and grids become smarter, the tools used to test and maintain these systems, such as the relay test set, are evolving to meet new challenges. By taking a series of countermeasures, the. The new generation of intelligent substations has achieved online monitoring functions for secondary equipment, making some state variables of relay protection equipment become observable indicators.