A Signal-Superimposed Technique for Fault Location in Transmission Lines Through IED Measurements Considering Communication Service Failure

Abstract

This article presents an innovative fault location algorithm utilizing an unsynchronized waveform measured from independent intelligent electronic devices (IEDs) installed in individual power substations without available wired or wireless communication link between the IEDs to establish the common timestamp required for the IEDs to record waveform data synchronously. The proposed idea is developed based on the positive-sequence waveform phasors with the superimposed-signal concept. A novel fault position indicator is proposed to yield an exact solution without being affected by unsynchronized measurement information because the unsynchronized-angle estimation is needless. Besides, the proposed idea does not require any assumptions, such as fault impedance, and is also free from computational complexity in as much as neither iterative operations nor fault type selections are needed. Last but not least, an extensive series of simulations and two field test results from the fault events of Taiwan Power Company have been presented to demonstrate the accuracy and practicality of the suggested technique.