On-line partial discharge measurement for insulation condition monitoring of HV cables

On-line PD measurement is an effective way for assessing the condition of high-voltage insulation in MV and HV power plants. With non invasive HFCT sensors PD activities of a cable could be detected while the cable is in normal services and prediction of insulation failure could be made based on the trend of the PDs recorded over a period of time. As this technology is relative new to the industrial applications there are still a lot of researches and development works to be done to solve the problems it is currently with in practice. The system and technique presented here in this paper is a new approach for online cable PD measurement, simple but effective. It utilizes HFCT and TEV as the sensors and can detect PD activities of a cable that occur at any point of the cable within 2.5km from the measurement point. It can also be used for diagnoses and record of PD activities for insulation failure prediction of a cable.