Accurate Fault Location Method and Verification Test Analysis of High-Voltage Cable Hybrid Lines

With the wide application of high-voltage cable-overhead hybrid line, it is difficult to determine the fault zone and accurately locate the fault point based on the line fault location method with uniform parameters. For this reason, this paper proposes a two-terminal fault exact positioning method based on wavelet theory. The power frequency transient signals of fault currents in the head and the end of high-voltage cable are collected to determine the polarity of the fault to locate the fault section. The fault current can be accurately located by collecting the double-ended traveling wave signal of the fault current. A 110 kV high voltage cable state simulation test platform was constructed to carry out fault simulation tests within and outside the high voltage cable line to verify the actual effect of the fault location method. The experimental verification shows that the two-terminal fault exact positioning method based on wavelet theory can accurately determine whether the fault point is located interval or outside the interval of high-voltage cable line, and achieve the precise positioning of fault points in the high-voltage cable interval. This method will effectively reduce the time of fault finding, and is of great significance for fast recovery of power supply.