Calculation of the Ionized Field Around the DC Voltage Divider

The space charges produced by the corona discharge of the DC voltage divider´s high-voltage electrode can move under the effect of the electric field force, and parts of them can attach to the surface of the insulation sheds. Because of the influence of the space charges and the charges on the insulator sheds´ surface, the electric field around has a big difference with the situation in the electrostatic field. In the paper, a 2-D axisymmetric upwind finite element method (upwind FEM) is used to calculate the electric field distribution on the surface of the DC voltage divider´s insulation sheds. The space charge density inside the insulation sheds is set to be 0, and the charge density on the surface of the sheds is calculated by the iterative process. The ionized field of a 3-D sphere electrode model is calculated, and the 2-D axisymmetric upwind FEM is verified by comparing the numerical results with the analytical results. In the end the ionized field of the 500 kV voltage divider is calculated. The simulation results show that the existence of space charges affect evidently on the electric field distribution characteristic, and hence improve the uniformity of the electric field intensity along the sheds surface.