Study on Relay Protection Coordination in Complex Auxiliary Power System

In many large-scale power plants, the structure of its auxiliary power system are complex, and the coordination of its relay protections is difficult. The Three Gorges Hydropower Plant is the largest installed capacity of power plants with complex auxiliary system. In this paper, the operation mode of auxiliary system in the Three Gorges Hydropower Plant is introduced, and some representative problems about the coordination of relay protection are raised and solved successfully.