Partial discharge measurement on high voltage plug-in GIS terminations based on capacitive sensors

This paper describes the partial discharge measurement on a dry pluggable high voltage GIS termination with integrated capacitive sensor for AC networks. It starts with the theoretical background which explains the working principle and integration of a capacitive sensor into a high voltage cable accessory. Further on, an electrical model for the integrated capacitive partial discharge sensor is presented. With respect to this, parameters such as sensitivity, frequency transfer function, attenuation co-efficient and bandwidth are investigated. All these theoretical findings are used to setup a simulation model which is then used to determine the performance of this capacitive sensor. The influence of the capacitive sensor on the performance of the high voltage cable accessory is investigated as well as the frequency response behaviour is also obtained. Subsequently, a prototype of such high voltage cable accessory was setup in the high voltage laboratory and analysed accordingly. The previously mentioned electrical parameters were measured and compared against the theoretically determined models. Additionally, the system was calibrated and verified in terms of the partial discharge results given by different kind of defects, representing typical installation issues. Finally, the results of this work are concluded and summarised.