An Expert System for Automatic Relay Performance Analysis

Abstract: Modern electrical power system is a very large scale of complex and interconnected system that the small disturbance easily would create havoc in power system stability and sustainability without operation of power system protection. In the analysis of power system protection the protection relay IED is the crucial part in order to prevent the unexpected event and maintain the integrity and security of the system. It is very useful at identifying problems with the fault relay settings or the algorithm of protection which could cause undesired operation and system disturbances. By replaying the recorded fault waveform which generated from the testing devices, the unexpected performance of the relay can be changed through the resetting of the parameters. Such analysis is complicated and expertise knowledge is usually required. Through such test running time of testing devices would usually demand very high cost. At the same time analysis of recognize and categories the faults to determine fault location and record data about fault level and fault resistance take lots of human resources in order to evaluate the correctness of the relay operation for a fault. The objective of this paper is to verify the performance of the relay IED through post-mortem analysis, the completion of design such system will help with operational decision making while saving working hour as well as the cost of running time of testing devices.