Novel Sensor Solutions for On-Line PD Monitoring

The electric utility industry is going through significant changes caused by new regulation models, distributed generation, increased competition and requirements for continuous improvement in the quality of power supplied to the customers. To minimize outages and supply interruptions, utilities must be able to monitor and locate faults more quickly and to develop condition monitoring in a more preventive direction. On-line continuous partial discharge (PD) measurement is an excellent way to determine the overall health of the medium voltage (MV) cables. Essential parts of a PD monitoring system are the sensors for measuring the high frequency PD signal. The continuous on-line PD monitoring of MV cables is a problem, primarily because no adequate cost-
effective sensor solution is available for permanent installation. The goal of this paper is to develop a low-cost, sensitive and robust sensor solution for continuous on-line PD monitoring of MV underground cable networks.