Partial Discharges Diagnostics Along Medium Voltage Cables

In the last years different partial discharge (PD) measuring techniques have been developed because PD diagnostic is the most widely tool to evaluate the insulation condition of a power cable. Recently non-conventional methods and sensors have been used in order to reach improved results in PD measurements. New sensors based on wireless technology were developed in order to simplify PD measurement especially for on-line, on-site diagnosis. The purpose of this work is to perform measurements that allow to study the variation of pulses when they travel along a medium voltage cable and characterize a new smart PD source detector and locator, named Wings sensor. For these purposes, internal PD signals have been acquired and compared with those detected by the dassical PD acquisition system. In addition, the characterization of the Wings sensor has been completed by acquiring PD pulses when the sensor is placed at different rotation angle and distance from the cable. It was found that for a better voltage magnitude signal the sensor should be placed in parallel with the cable and in contact with it.