Simulations of Thermal Profiles in Lead Sealing Layer of High Voltage Power Cable Under Faulty Scenario

In recent years, high voltage cables suffer from various localized heating faults due to internal defects in the sealing layer. In view of the formation mechanism of such heating faults, this paper investigates the thermal profiles inside different layers of high-voltage cables through electric-thermal field coupling numerical simulation. Firstly, the simulation of thermal profiles inside power cable during normal operation is carried out to observe the temperature rise characteristics in practical. Secondly, air-hole type defect is set inside the 2-D cable structure to analyses the temperature rise performance under faulty scenario. The simulation results show that the local hot-spot temperature gap between two sides could increase by about 0.1 K when air-hole type defect is present in the lead seal layer of the power cable and current source in 2000A is used, compared to the temperature distributions in power cable during normal operations. The contributions of lead sealing layer defect on thermal profiles are key for optimized design of power cable structure and guarantee the long-term operation of the power transmission system.