Instrumentation and concept of partial discharge and temperature cable monitoring

Starting with practical examples of latent and identified defects in cables the motivation and the benefit of cable monitoring is explained. Different sensor technologies for monitoring are introduced and classified considering the physical method of operation and particularly the field and quality of their application for cables. Sensors for implementation before and after installation of the cable are described. The presently most popular technologies for cable condition monitoring are partial discharge sensing and distributed temperature sensing. The paper shows details and new developments of both methods. After acquisition and processing of the recorded sensor signals, a reliable data evaluation and trending is necessary. With advanced platform independent database systems a condition based assessment and maintenance of the most valuable assets of the power industry can be realized. The insulation performance of the cable system is recorded on-site, permanently or periodically. The early detection and location of defects can be realized and the operating load of cables can be optimized. Monitoring is the tool to setup maintenance strategies with a progressive lock a head. It is the way of improving our power quality and supply-reliability and of managing the assets in the power industry.