Online Partial Discharge Localization in Branched MV Joint

Single and double side measurement methods have been reported for partial discharge source localization during online partial discharge (PD) measurements in medium voltage networks. However, these methods cannot be applied directly in branched networks due to the presence of multiple reflection points. The PD current pulses propagate simultaneously in the core and the earth screen of the cables with opposite polarities. Such pulses are negative during the positive half of the voltage cycle and vice versa. This paper studies the partial discharge source localization in branched networks by applying the direction of arrival of the pulses and peak pulse magnitude concept when HFCT sensors are used during the online PD measurements. The PD pulses tend to travel away from the discharge source and this property is utilized to identify the defective branch in a tee joints by tracing the PD pulses during their propagation. Lab studies of the pulse propagation were performed using online PD measurement systems, and the results are reported in this paper.