Condition Assessment of Medium Voltage Underground Cable Systems

This paper presents condition assessment of medium voltage underground cable system. Various testing methods and diagnostic techniques are presented to find a defect of individual underground cable components such as withstand voltage, partial discharge, dielectric loss or tan delta, and visual inspection. Subsequently, technical criteria for condition evaluation is defined. Then condition assessment is carried out by applying the weighting and scoring method to determine health index of underground cable components and cable system. Finally, the overall health index is modified by a conditional multiplying factor to incorporate the influences of practical operating condition and installation type. The overall health index enables the utility to prioritize the preventive and condition-based maintenance of underground cable system.