Development of a Live Line Partial-Discharge Detection Method for XLPE-Insulated Copper Wire-Shielded Cable Using a “Yoke Coil”

Abstract

This paper describes a new partial-discharge detection method for an XLPE-insulated copperwire-shielded cable line using a “Yoke coil”. Partial discharges are measured with the Yoke coil which detects the azimuthal component of the current flowing through the copper wires wound on an outer semi-conducting layer with a given angle against the axial direction of the cable.
The highest detection sensitivity of 2 pC have been achieved at a frequency range of 5-20 MHz using a 77kV 100mm² model cable line (200m in length). It was confirmed that the partial discharge caused by an artificial defect has successfully detected using the proposed method.
In the PD measurement for an actual 77kV XLPE insulated live line, the detection sensitivity was 10 pC.