A New Method for Remote Testing Distance Relay Using Internet Protocol Version 4

The bulk of studies on power-system protection focus on fault detection algorithms in protective relays. However, a major part of protective relays problems come from their hidden failures. Hidden failures are not detected in the normal network state. They will be detected when an error occurs in a power grid where a relay malfunctions. This can make the power grid unstable. To prevent such an occurrence, protective relays need to be tested periodically. Such tests are very time-consuming and costly especially in remote substations. Based on the Internet Protocol Version 4 (IPv4), a new method is proposed in this paper for remote relay testing. This method allows a technician to test a relay remotely. In addition to low-level tests (such as shot test), the proposed method can carry out transient tests. The proposed method is implemented thoroughly on an AMT-105, a relay tester made by Vebko Amirkabir Company. Then the applicability of the proposed method was tested and analyzed completely using a distance relay of a real-life substation.