Flexible Multi Sensor Monitoring System for Medium Voltage Cable Joints

Degrading cable connections are a major problem in the medium-voltage grid. Early failure detection is therefore very important. In this paper, a flexible, small-sized, self-sufficient wireless monitoring system for medium voltage cable joints is presented. The system can be fitted easily around all common power cables with shielding and cable joints. Even the current induction energy harvester has a flexible design. From a current flow of around 15 amperes, the radio electronics and sensor technology are supplied with sufficient energy. With the help of the integrated sensors, partial discharge (PD), fault current, over-temperature and external impacts like vibrations or shocks can be measured. The whole sensor node including radio, sensors and energy harvester is designed for and practically tested in a wide operating temperature range from - 40 °C to + 110 °C. The system is currently undergoing extensive field tests.