Robust Fault Location Method for Transmission Lines Using PMUs

The random noise and abnormally greater numbers may affect the accuracy of traditional transmission line fault location. A robust fault location method for transmission lines based on PMUs (Phasor Measurement Unit) is proposed in this paper. The node voltage equations based on voltage fault components are adopted to establish the quadratic nonlinear overdetermined equations of fault location, only using limited PMUs adjacent to the faulted line. In order to quantify the impact of measurement errors, the residual errors are introduced into the fault location equations. Levenberg-Marquardt (L-M) algorithm has been used to solve the equations. Then the original fault location data at each time after the occurrence of one cycle is obtained. A filtering method is proposed to filter the possible interference such as noise and abnormally greater numbers in fault location sequence. The abnormal data that deviating from the mean can be detected by the probability distribution and replaced by smooth filtering data. The simulation results on IEEE 39-bus systems show that proposed algorithm can effectively improve the location accuracy, is not affected by the fault location, transition resistance, fault type, and has strong anti-interference ability and good robustness.