Partial discharge monitoring and locating in substation using multiple sensors in parallel

Partial discharge (PD) monitoring is accepted as the most effective means for insulation diagnosis of high voltage power devices, since it can detect PD defects in early time. However, the methods for PD monitoring of substation equipment are mainly oriented to single device, which require to process on every equipment, cause to high cost, and huge maintenance workload. This paper proposed a PD monitoring system that utilizes multiple sensors connected in parallel to a single cable loop to monitoring PD signals originated by devices in substation. The PD signals are detected by the sensors and transmitted around the cable loop in both directions. A characteristic time delay exists between the measured signals on the two channels for all signals entering the cable from sensor, which is used for PD locating. This paper also focused on the structure of the proposed system, the locating algorithm and proved the feasibility of the system by experiment.