Research On Relay Setting Coordination For Distributed Network And Its Key Matters

Relay setting Coordination is the basis of secure operation of modern power system, and is of great importance to the reliable function of relays. Sensitivity, selectivity and speed of the protection devices could be guaranteed by the appropriate settings. This dissertation devotes to the key matters in the relay coordination for distributed networks, including research on coordination automation technology, coordination theory and the design of coordination software for distribution power grids.First, several main forms of relay protection for distributed networks are sorted and presented in details; also covered are the basic principles of the coordination work.In respect of coordination automation technology, different operating modes are summed up and analyzed; a new searching method based on the one-sided power supply operating mode is put forward. To improve the inefficiency of searching, an improved depth-first searching approach is adopted in the method on the concept of power supply level.As for the aspect of coordination theory, this paper makes a tentative study on two special kinds of line coordination——the reverse cooperation and the cooperation for different types of protection. With their causes and influences on relay operation presented, the solution for each is proposed. In addition, the standard inverse time characteristic equation for relay is introduced, and its cooperation is also discussed.Based on the above key matters, protection device integrative coordination system for distribution power grids are designed, whose main structure and functional division are circumstantiated, and pivotal approaches during development are proposed. The system realizes the automation of power grid management, fault calculation, coordination and setting requisition management. What's more, various methods of manual interposal are provided to enhance its adaptability and flexibility.