Effect of diffusion on space charge formation in dielectrics under steady-state DC conditions

Abstract

Despite copious experimental results, space charge formation in dielectrics is yet to be understood. Dynamics of current conduction across dielectric specimen is attributed for the formation of different types of space charges. However, analytical treatment of relation between conduction and different types of space charge formation is scanty in the literature. As a first step, the author presents analytical solutions to the steady-state dc problem including the effect of diffusion. The author's solutions throw light on certain experimentally observed space charge phenomena in LDPE and found to match with experimental results available in the literature. Several interesting results/observations are presented in the paper.

Role of external and internal parameters on the space charge formation in dielectrics

“…The present work is a small extension to the authors' previous work [12]. In this paper, the effect of volume resistivity and injection current on the type of charge formation has been investigated.…”

“…For several years now, the current continuity equation has been in use for determining electric fIeld and space charge [11][12][13][14][15][16][17][18][19], However, its adequacy and legitimacy has hardly ever been stated. Jefimenko [20] and later Heras's existence theorem [21], proves that the current continuity equation is the fundamental equation and recognizes charge conservation as the fundamental axiom underlying Maxwell's equations.…”

“…Certain simplifying assumptions were made to find a solution [12]. In the light of the solution presented in [12] by the authors, several interesting results on the effect of internal and external parameters on the steady-state space charge formation have been presented in this paper.…”

Conduction and space charges in polymeric dielectrics and nanocomposites

“…Joint solutions of current continuity equation and Poisson's equation for steady state charge and electric field profile in a dielectric sheet specimen have been reported by the author in his earlier work [16].…”

On the resolution of raw charge signal and de-convolved signal of a PEA system

“…Although thermal origin of breakdown is most popular [2][3][4], it is also believed that space charge formation [5][6][7] could also initiate/hasten breakdown process and may also influence insulation ageing. Different methods have been developed for space charge measurement [8].…”