Electric field analysis of extra high voltage (EHV) underground cables using finite element method

Transmission and Distribution of electric power through underground cables is a viable alternative to overhead lines, particularly in residential or highly populated areas. The electrical stresses are consequences of regular voltages and over voltages and the thermal stresses are related to heat produced inside the conductor due to flow of high rated current which is the main factors that affect its reliability. The performance of these underground power cables is important for proper operation of the power system. Long-term problems with them are related to the degradation of polymer materials used for the insulator due electrical, thermal or environmental stress. Most of these problems are related to the electric field stress on the insulation of the underground cables. The objective of the electric field analysis by using different numerical techniques is to find electric field stress and other parameters, which are an inevitable tool in various electricity concerned technologies; in particular for analyzing discharge phenomenon and designing Extra High Voltage (EHV) underground cables. In this paper Finite Element Method (FEM) numerical method has been discussed and used to find 2-D electric field stress and other parameters of EHV underground cables with given boundary conditions using 2-D electric field analysis software package (IES-ELECTRO module) which is based on the finite element method (FEM).