OMICRON Magazine

Magazine | Issue 2 2020 Figure 2: Test setup on controlling end – Testing traveling wave protection relays with TWX1 was controlled from one PC (Figure 2), which communi- cated with the remote end via a cellular modem (mobile hotspot). The time-synchronization and timing between the local and remote terminals were ensured by two CMGPS 588 units (grand master clocks). Once the testing equipment was installed, the communication and connections were verified by comparing the relay metering with the programmed inputs. Results: Reliably testing traveling wave relays with TWX1 While using this test setup, faults were simulated at various points along the protected line and adjacent busses. When it came to faults in the line, the measured traveling wave differential element trip times ranged from 1.0 to 2.3ms. The fault location error was less than 20m in all test cases compared to the simulated fault locations. When we tested the incremental quantity distance elements, communication was blocked, and the tests were repeated. The measured trip times of the faults in the line ranged from 2.9 to 4.2ms. In both cases, the operations for the faults simulated in adjacent buses were blocked properly. The test results were confirmed a short time later when an actual fault occurred. The relay reported a distance of 6.47 miles (10.41km), which was within 100 feet (30m) of the actual fault location at 6.45 miles (10.38 km), with relay trip times of 0.9ms (Micromill One) and 2.1ms (Dinosaur). Traveling wave protection relays and fault locators are definitely going to be part of future protection systems. By simply adding our TWX1 accessory to your differen- tial test setup, you can already put them through their paces and ensure their proper functionality by simulat- ing faults with precision-injected traveling waves. Find more information at www.omicronenergy.com/twx1 9