Measuring Yearly Variation of Temperature of Medium Voltage Cable Joints

In the last years, Italian Distribution System Operators (DSOs) have recorded an anomalous number of faults in underground medium voltage (MV) cable lines, especially during hottest months. This work presents a thermal analysis of MV cable joints, especially focused on cold-shrinkable type since it is one of the most commonly installed in Italian distribution networks. The paper reports and discusses a measurement campaign of temperatures within and around the joint considering real operating conditions; data have been gathered during one-year, with the aim to assess thermal stress of joints. Furthermore, a 3D thermal model already presented and discussed by the authors in previous papers has been accurately validated and also extensively applied in this study. Measurements and simulation results show that the joint is a cold part of an underground cable line and that overheating does not occur in any considered scenarios, even in the most critical ones.