METHOD FOR DIAGNOSING INSULATION DEGRADATION IN UNDERGROUND CABLE

摘要

The invention provides a method of on-line diagnosis of insulation degradation in a portion of underground cable including measuring the current flow at first and second locations of the cable utilizing an optical current sensor at one of a number of current frequencies, determining the current flow differential at that frequency, and analyzing the results of the current flow differential determination according to a corrosion test, a partial discharge analysis, a harmonic current analysis or a tangent delta diagnostic.