Power cable fault locating based on frequency difference characters of wavelet analysis

In order to improve the accuracy of on-line single-end fault locating for power cables used in radial medium voltage distribution system, the reflection and refraction frequency difference characters of voltage traveling waves at different position of cable distribution power system, is studied. The arriving time of voltage traveling wave is defined by the modular maximum of wavelet transform results, while the phase-frequency characters of preferred wavelet filter are used to abstract the intrinsic frequency difference information to effectively determine the second arriving voltage traveling wave is from the fault node or the opposite bus. A distribution substation model is simulated in EMTP and its simulative result shows that, the power cable on-line single-end fault locating based on wavelet analysis frequency difference characters has higher accuracy. This project is supported by the National Natural Science Foundation of China (50577059).