Search

Medium-voltage cable joints are one of the critical components of the distribution networks. They represent the first cause of faults and outages. Among the others, partial discharge, dielectric, and temperature measurements are the typical tests performed for investigating over the early aging of such critical components. In this paper, a new study has been completed correlating the cable joint tangent delta (Tan $\delta$ ) value to the external pressure applied on the insulating material surrounding the joint. Results confirm the presumed correlation. In fact, an increase of pressure results in a Tan $\delta $ decrease, hence in an extension of the cable joint working life.

With the purpose of understanding more and more the causes of fault for MV cable-joints this paper deals the interfacial pressure vs. temperature issue. By starting from results obtained by the authors in the field of cable- joints, firstly a test bed for pressure measurements is developed and characterized. Afterwards temperature test cycles have been defined to measure how temperature affects the interfacial pressure (XLPE/Silicon rubber) inside the cable-joints. Presented results confirm the accuracy of the developed setup and the pressure vs. temperature behaviour of two different cable-joints.

As reliable power network is crucial to deliver promised electric power, cable powerline monitoring in medium voltage networks has a great importance for Distribution System Operators (DSOs) all over the world. A considerable rate of failures in cable powerlines is referred to the cable joints. Especially during the summer period, an excessive number of joints are subjected to explosion, causing outages in different points of the power network. To this purpose, in this paper, a simple and cheap test setup has been designed and calibrated to perform one of the key measurements for the cable monitoring, Tan Delta. Finally, the Tan Delta of different joints have been measured using the proposed setup.