GPS TRAVELING-WAVE FAULT LOCATOR SYSTEMS - INVESTIGATIONS INTO THE ANOMALOUS MEASUREMENTS RELATED TO LIGHTNING STRIKES

A new fault location system based on the travelling wave principle and capable of locating faults on power lines to within +/- one tower spa n (300 m) has been successfully developed and applied to B.C. Hydro's extensive 500 kV network. Unlike earlier schemes which are based on im pedance measurements, its accuracy is not affected by load conditions, high grounding resistance and most notably series capacitor banks. Th is system measures the time of arrival of a fault-generated travelling wave at the line terminals using the precise timing signals from the Global Positioning System (GPS). Operating experience with the fault l ocator on lightning related faults indicated highly accurate results w ere obtained for the majority of the cases. In a few of the lightning- caused disturbances, the system gave anomalous measurements. This pape r describes the operation of the system, summarizes the operating expe rience and explains the observed anomalous measurements.