Identification of aged cable section in 12.5 kV URD system using EMTP simulation

Underground distribution power cables are aged due to electrical, thermal, mechanical stresses and environmental stress during their service. For utilities, the recent dielectric conditions of the cables are of much interest. Some destructive and non-destructive methods are available to estimate the actual status of the cable insulation. One of the methods is to estimate the cable insulation condition by using Fast Fourier Transform Analysis of impulse wave propagation in URD cable system. In this study, the radial URD system was modeled by using EMTP for transient studies. The model simulates the new cable and different aged cable conditions. Travelling impulse was simulated in the energized model of the URD system. Based on the Fourier analysis of the simulation results, a methodology to identification of the aged cable section is presented in this paper.