Distributed PD measurement on power underground cables

In this paper a multi point partial discharge (PD) measurement approach is presented and named as distributed PD measurement (D-PDM). These D-PDM technique records PD pulses using an ultra wide band system that allow spatial discrimination due to high frequency signals rapid decay while displaying the output in a traditional Q-F-N pattern to facilitate problem identification. D-PDM was applied to evaluate an underground radial and meshed distribution networks with over 70 three phase PILC circuits while in normal operation. Several incipient fault sites were located and a predictive maintenance program established using this technique.