Numerical study of heat transfer in high voltage solid insulating materials using transmission line method

Abstract

Purpose The purpose of this study is to numerically examine the heat transfer and transport of space charges in the solid insulating materials [low density polyethylene (LDPE), flame retardant type 4 (FR4), Polytetrafluoroethylene (PTFE)] using the transmission line modeling (TLM) method. Besides, a comprehensive study is performed on the mutual influences of heat transfer and space charges transport within the solid dielectric bulk. Design/methodology/approach The obtained governing equations including continuity and circuit equations are coupled with heat transfer equations, and they are solved via fourth-order Runge–Kutta method. Findings The electric potential and field, current density and temperature distribution are calculated. It is shown that compared with FR4 and PTFE, the temperature increment rate in LDPE is much lower. Moreover, the heat transfer in the solid insulating materials bulk increases the homo-charges density and temperature in the vicinity of electrodes. Hence, the reduction in electric field is reflected in the potential deformations in the proximity of electrodes. Furthermore, where the electric field is maximized, the temperature is minimized. Research limitations/implications This study is restricted to two-dimensional problems. Originality/value Interestingly, because of the lower temperature in LDPE, the current density and their increment rates in LDPE are much lower than that in FR4 and PTFE dielectric materials.

Research on application of LU decomposition and CG method in nonlinear iteration of transmission line finite element method

“…The TLM connects the lossless transmission line with the nonlinear resistance to form a new circuit network. When the excitation is connected to the transmission line network, a time-varying incident voltage and a reflected voltage will be generated in the transmission line, and there is a delay time between them (Lobry et al , 1996; Im et al , 2001; Amin et al , 2022). This delay provides the decoupling of the circuit nonlinear equations, so it can be used to solve the nonlinear equations.…”