Multi-Physical Sensor Fusion Approach For Partial Discharge Detection On Medium Voltage Cable Connectors

Abstract

The novel idea of this work is the simultaneous use of different sensors for partial discharge (PD) measurement and monitoring of medium voltage cable connectors. The measurement with one sensor or with several identical sensors may entail inaccuracies, caused by noise or external interferences, etc. To increase the validity and reliability of the PD measurements, various sensors could be fused into a multi-sensor system. In this study, six different sensors are investigated. The well-known HFCT sensor for the inductive PD measurement is compared with the capacitive approach. A new low-cost capacitive sensor is introduced, which is fixed around the cable connector. Capacitive PD measurements are realized over the bushing of the switchgear, as well. Electromagnetic PD detection is implemented using a loop antenna and leaky feeder cables. The latter mentioned sensor is a new approach for PD measurements in High-Voltage (HV). The last sensor is an ohmic sensor, which is realized using the earthing cable of the cable connector. The proper installation of sensors on the cable connectors plays a key role in PD detection and is therefore discussed in detail. If the electric field of cable connectors is not carefully regarded, the sensors themselves may produce discharges. That is why the electrical field of the cable connector is investigated using a 3D FEM simulation in the first step. Row measurements of different 10 kV cable connectors with PD faults are performed in an MV switchgear. The sensors are correctly installed, and a self-developed low-cost monitoring system records the PD activity. The measurements are discussed in detail. Using well-known PD analysis patterns, the effectivity of the system is shown.