The infuence of traveling wave at single-core cable’s cross-connecting point and passive coupling method

According to travelling wave fault location’s difficult problem caused by the high travelling wave refectivity at cross-connecting joint of single-core cable, a passive coupling method is introduced. Based on the high-pass characteristic of capacitor, this method adds coupling capacitor at cable cross-connected box, thereby reducing the travelling wave refectivity at cross-connecting joint. The wave impedance of single-core cable and intermediate joint is theoretically calculated. The normal cross-connecting method, the passive coupling method and direct short method is simulated and analyzed by EMTP, then is really tested on 110 kV cable’s travelling wave fault location. It is verifed that the passive coupling method has lower refectivity for travelling wave signal. The passive coupling method which use capacitor can effectively raise the effciency of travelling wave fault location, while has little infuence on induced voltage and induced current at industrial frequency, and has a good application prospect.