Charge concept in partial discharge in power cables

Present paper discusses Partial Discharge (PD) occurrence and its relevant parameters in power cables. A spherical void in the insulation of a power cable is assumed as the origin of PD. To study PD in power cables, a model based on the three capacitor type is proposed, and the associated circuit elements for the spherical void and different layers of the cable are obtained with closed form solutions. In the procedure of deriving parameters of the model, a defect column is selected with a particular geometry which its boundaries are in the direction of the electric field. The results for PD magnitude and current pulse are acquired from the proposed model, along with Finite Element Method (FEM) simulations. Both methods show matching results but in contrast with the dipole model. FEM simulations are accomplished in 3D, on account of spherical geometry of the void. Other simulation results achieved from FEM and the model are as well included.