The Functional Relation between Partial Discharges and Induced Charge

Analytical expressions are deduced for the quantitative evaluation of the charge induced on an electrode by a partial discharge (PD) within a dielectric body. Two approaches have been employed to effect this evaluation. These are characterized by the X function and the $ function, and the essential relationships to be fulfilled by X and q5 are derived. The principal difference between these functions is how t he dielectric polarization is accounted for, either implicitly ( A ) or explicitly (4). This difference is brought clearly into focus. Thereafter the application of these functions to PD studies is considered. I t is demonstrated quantitatively that perturbations in the dielectric polarization, brought about by the PD, can contribute significantly to the magnitude of the induced charge. As a consequence, the currently accepted approach to PD energy considerations should be re-examined.