Practical Study on the Lifetime Prediction of High Voltage Cross-Linked Polyethylene Cable (XLPE) using Thermal Aging

A high-voltage and medium-voltage cable distribution network is an extensive section of the distribution route. The electrical cable system remains the most important channel or brain connection that allow all other dynamic section to function. Since the electrical cables system is entrenched often it is challenging and costly to install new ones. When the cable ages, a degradation of the electrical and mechanical properties of the insulating material occurs triggering irreversible changes in the chemical construction and hence reducing the service life of the cable. When the conductor operating temperature increases, there is a subsequent speeding up of the XLPE aging process, and consequently a reduction in the life of the cable. The key objective of this paper is to present a model for determining the thermal aging of XLPE HV cables. In addition, this paper examines the thermal aging of high voltage XLPE cable for HV distribution network, using consistent load. Based on the cable properties such as the insulation temperature, thermal aging is determined using the Thermal Aging model and Arrhenius law. In this work, the model is developed based on this premise to predict the lifetime of a 132kV, single core, 1000mm2 Cross-linked polyethene (XLPE) cable. This paper specifically implements the lifetime model of a high-voltage cable using thermal aging. The results show that when an XLPE cable is operated at a lower temperature of 70C is likely to survive many years (+50 years) in service, than when it is operating at a normal cable operating temperature of 90C.