Use of True PD producing Defects for Calibration and Sensitivity Check of UWB PD Sensors

Predictive maintenance of high voltage equipment requires levels of partial discharge warning to trigger corrective action and prevent failures. This leads to the need of establishing a reliable way to compare readings from different on-tine and conventional off-line partial discharge detection systems. To achieve comparable results, it is suggested to use controlled defects including sharp point metal needles or spherical voids cast in epoxy resin used in previous works. In this paper, a methodology is presented to install those samples inside a piece of equipment and generated real partial discharge signals with varying magnitudes pulses. That type of samples produces repetitive and well defined partial discharge signals that can be accurately measured using either traditional or modern ultra wide band (UWB) detection. Once those PD signals are recorded, their effects can be detected by any UWB sensor located anywhere in the vicinity of the PD generating defect The sensor output can then be related to the input charge depending upon the sensors transfer function, and position. This known PD pulse can be used to simultaneously compare different sensors geometries and philosophies to define permissible PD levels that will trigger corrective maintenance actions.