A Novel Partial Discharge Locating System for 10-kV Covered Conductor Lines in Distribution Network

Partial discharge (PD) testing has proven one of the effective methods to evaluate the operation condition of 10-kV covered conductor (CC) lines and predict the permanent faults. Power utility technicians usually patrol the CC lines with the ultrasonic testing devices to seek PDs. Although this strategy is effective, it is costly and time consuming for utilities to manage the vast distribution network. Therefore, the objective of this paper is to develop a practical PD locating system to enhance the testing and maintenance efficiency of CC lines. A novel double-sided traveling wave method utilizing artificial generated pulses for synchronization is proposed and applied in the system. Through a pulse-injection mechanism, the double-side units can be synchronized while the length of CC lines between these units can be estimated. Synchronization of both side units and implementation of the system is described in details. An on-site validation experiment was conducted on a 3.954-km 10-kV CC line under operation and results showed that the proposed system could effectively locate that PD defect.