Identification and Localization of Partial Discharge in Power Cable Based on Phase Space Vector and Energy Criterion

Identification and localization of partial discharge (PD) are important part of condition monitoring and diagnosis of power cable to ensure their reliable operation. In this paper, a PD detection system is developed, which consists of high frequency current transformer, signal conditioning circuit, data acquisition unit, and analysis software. The phase space vector method is proposed for identifying the type of detected signals. By calculating the correlation coefficient between the phase space vector graph of real-time detected signal and typical signals, the type of real-time detected signal can be determined by which signal identification can be realized with less data calculation and high efficiency. For realizing the automatic PD localization in power cable, the energy criterion method is proposed for determination of the time delay between detected PD pulses. The developed PD detection system and proposed methods are applied in field tests, it is verified that the insulation defect in power cable can be identified quickly and localized automatically.