Statistical characteristics of partial discharge caused by typical defects in cable joint under oscillating voltage

The oscillating voltage test is a nondestructive detection method for partial discharge of XLPE cable and has been applied recently. This paper made three kinds of varying severity artificial defect model of cable joints in 10 kV XLPE cable. Oscillating voltage is applied to the model, by use of pulse current method to detect partial discharge signals. In order to study the statistical characteristics of partial discharge of cable joint under the oscillating voltage, three-dimensional statistical map has been made. The results show that for the same kind of defects, with the increases of the defect severity, the discharge interval extended, the magnitude and the number of partial discharge increase; for different kinds of defects, obvious difference exist among the maps, this may established a foundation for the further study of the partial discharge pattern recognition of XLPE cable under oscillating voltage.