Partial Discharge Source Characterization within a HV Cable Joint

A parameter for partial discharge (PD) source location within a joint bay of a three phase cross-bonded high voltage cable circuit has been assessed. Locally placed sensors can detect PD pulses that propagate within the fault related phase. However, when a cable joint bay is cross-bonded then PD signals from one phase may be measured by sensors on the other two phases as well. Current research at Southampton is considering the practical application of on-line PD monitoring techniques to three phase high voltage cable joints. A simple model, using 66kV cable sections to represent a cross-bonded circuit has been implemented. The model uses one capacitive coupler per phase. Measurement data was obtained by injecting pulses into the core conductor. Data was analysed using a clustering technique in order to determine the PD source location.