LOCATION AND CHARACTERIZATION OF PARTIAL DISCHARGE SITES IN SHIELDED POWER-CABLES

An instrument capable of detecting and locating partial discharge sites and faults in shielded power cables was developed on behalf of a group of U.S. electric utilities. The instrument uses state-of-the-art electronic hardware and advanced digital signal processing techniques. The partial discharge signals are reconstructed using the cable traveling wave characteristics (transfer function) and noise is reduced both through a judicious choice of hardware and by modern signal enhancement techniques. An adjunct instrument was also developed to correlate the location of a partial discharge site along the cable to the position along the surface of the cable burial trench. The paper describes the principle and the implementation of the instrumentation package and discusses results obtained in the laboratory on a 175 m, 15 kV URD cable. A companion paper discusses in greater detail the signal processing techniques. © 1990 IEEE