A Troubleshooting Methodology for Issues Discovered During End-to-End Testing

Abstract

Transmission line protection is a critical part of maintaining power system stability. A number of system components are taken into consideration when creating protective settings: capacitive/reactive series elements, accurate power system modeling, varying standards between interfacing utilities, etc. Due to the varied nature of network topology, it is crucial that line relay settings are tested in a manner that will reflect actual use. The best way to test the protective intent of these settings is through fault simulation, or “end-to-end” testing. There are a number of issues that can be discovered by performing end-to-end commissioning of protective line settings. This paper will provide real examples of problems found during line relay commissioning, and the troubleshooting methodology used to resolve them.