Partial Discharge Pulse Propagation, Localisation and Measurements in Medium Voltage Power Cables

This paper considers the measurement and propagation of partial discharge pulses on distribution class power cable circuits, with the idea of attempting to determine discharge location sites on cables based on the parameters of individual pulses. Single-ended discharge location techniques based on partial discharge pulse parameters and shape will not be as accurate as time-domain reflectometry methods but can be done on-line without the need for double-ended techniques. Power cables used for the transmission of 50/60 Hertz electrical power, are by design not intended to carry transients or partial discharge pulses. The geometry and construction of such power cables present a transmission line that can heavily attenuate and distort the partial discharge pulses, making their detection and discrimination all the more difficult. Experimental and field work has been carried out to develop basic knowledge rules to describe how the time-domain parameters of individual pulses alter as a function of the distance propagated from the discharge sites for medium voltage power cables.