Research On Checking Relay Protection Setting For The Change Of Grid Structure

Relay protection is the first line of defense for the safe and reliable operation of the power system,among which the protection setting is particularly critical.Conventional methods are to set the relay protection setting in the maximum operation mode and to verify the minimum protection range of the setting value in the minimum operation mode.However,when the grid structure changes,the protection setting may not meet the four properties of relay protection.In order to make protection setting adapts to the current grid better,online verification of protection setting plays a significant role.This work focuses on the online verification of the performance of the protection setting under the N-1 maintenance mode when the grid architecture changes.Taking Tangshan Power Grid as the research object,the selection performance of the phase-to-phase distance II of the Penning line at the 220 kV Bencheng station was verified.Meanwhile,the results of the online verification were recorded,which were showed by visualization technologies.The performance of the protection setting was finally analyzed according to the grid's topology results and verification results.We first analyzed the ideas of setting calculation and online verification of relay protection,from which we can conclude that they are reversible.Based on the D5000 platform,the verification system's system architecture,data architecture,technical architecture and functional architecture were then introduced.Online verification method for verifying each performance was proposed based on the idea of setting.Third,the principle of branch-adding method was introduced.We applied this method to the branch inspection and repair of online verification system,which greatly improved the online verification speed.Finally,taking the Tangshan Power Grid as an example,the branch-adding method was applied to the online verification under N-1 overhaul.By analyzing the online verification process and results,the adaptability of the protection setting value to the current power grid was verified.The proposed online verification system has been successfully applied to Tangshan Power Grid.Moreover,this system verified the performance of the protection setting for users,which has been well received by users.