Application of nonlinear finite element method in DC steady E-field calculation of composite insulation structure

Abstract

The DC steady E-field is a state of composite insulation in the converter transformer outlet barrier system. The electrical properties of insulating material are both function of electric stress and temperature, thus, changes of electrical parameters due to temperature gradient will affect the DC steady E-field distribution of composite insulation structure. Based on this, to accurately simulate DC steady E-field of composite insulation structure with temperature gradient, this paper applied nonlinear finite element method to the coupling analysis of these two affecting factors. Firstly, relationship between electrical parameters of insulation materials and temperature, electrical stress was investigated. Then, the DC steady E-field calculation method with nonlinear finite element was proposed and verified by the simple coaxial insulation structure model. Finally, 2D simulation model of barrier system was established to simulate and analyze the DC steady E-field considering nonlinear characteristics of materials. The results show that the results of traditional simulation are quite different from those when considering material nonlinearity. The nonlinear finite element method proposed in this paper and the calculation results provide references for the design of converter transformer outlet barrier system.

Experimental study of pollution and simulation on insulators using COMSOL® under AC voltage

“…Consequently, the flashover can occur in the operating voltage. This phenomenon may affect the security and stability of power system [3][4][5][6][7].…”

“…The flashover phenomenon is one of the most complex problems observed in high voltage outdoor insulators by numerous researchers, [7][8][9][10][11]. In particular, the final stage of the complex mechanism that occurs when an intermediate pollution band forms on the insulating surface has been highlighted [12][13][14][15].…”