Development of a transmission line fault location platform using digital relay data

In Taiwan, all of the protection relays for 161kV/345kV transmission lines of Taiwan power (Taipower) system have been upgraded to digital types with built-in fault location function since 2007. However, multi-section compound lines and also tapped lines result in significant fault location calculation error using relay built-in function. Therefore, a new transmission line fault location platform with digital filter function and asynchronous measurement angle calibration function was developed in order to obtain more accurate and more reliable results. In this way, maintenance engineers can easily verify the waveforms of fault signals and obtain reliable fault location estimation. This fault location platform has been verified by field event data in Taipower.