SEMIEMPIRICAL HIGH-FIELD CONDUCTION MODEL FOR POLYETHYLENE AND IMPLICATIONS THEREOF

A semi-empirical model for high-field conduction in polyethylene is developed on the basis of data in the literature for ac conductivity in the range of 30 to 60 kV/mm and 'charge injection' from a needle in the range of 160 kV/mm. The model is used to compute high-field conduction-related phenomena by solving Poisson's equation with field-dependent conductivity and time-dependent applied voltage for a highly inhomogeneous field geometry. Parameters computed include field, current density, charge density, power density, and force density. Temperature rise in the dielectric is estimated based on the computed power density.