Test studies and analysis aged medium voltage cables

Medium Voltage (MV) cables, vital for electrical energy transmission and distribution, are manufactured to meet international standards and specific criteria. To assure performance and reliability, these cables undergo various electrical and mechanical tests in a laboratory for thorough analysis. This thesis focused on a 1x400/35 mm² NA2XSY type 20.3/35(42) kV MV cable, widely used in Türkiye and produced according to the TSE K 204 criteria. Both mechanical and electrical tests were performed on this cable. The investigated 20.3/35(42) kV MV cable was aged per the TSE K 204 criteria, undergoing 20 heating cycles, each lasting 8 hours. Furthermore, in addition to the heating cycle aging procedure specified in the standard, a second heating cycle of 20 cycles was applied to the cable. Before and after these cycles, partial discharge and tanδ measurements were conducted. Furthermore resistance measurement and spark testing, the cable underwent several mechanical evaluations: shrinkage, cold impact, pressure at high temperatures, elongation at low temperature, and tensile strength before and after aging.The measurement results were thoroughly analyzed to observe insulation behavior over cycles and identify any non-standard degradation. The simulation model of the heating cycle experiment was developed based on the finite element method (FEM), considering induction heating as a multiphysics problem, and results were compared with temperature data obtained from laboratory tests. In conclusion, the comprehensive mechanical and electrical tests performed on the 1x400/35mm² NA2XSY 20.3/35(42) kV MV cable were instrumental in determining its conformity to TSE K 204 criteria, quality, and durability.