Surface current density K: an introduction

The author discusses the vector surface of current density K used in electrical insulation studies. K is related to the vector tangential electric field K_t at the surface of a body by the vector equation K=ΓE _t where Γ represents the surface conductivity. The author derives a surface continuity equation that represents the boundary condition which the potential distributions in the adjoining media must fulfill. The volume current may be small in comparison to the surface current, and consequently in deriving the potential solutions the first term in this equation can sometimes be neglected