Results
Tangential Electric Field, z-Component
1
In the Home toolbar, click Add Plot Group  and choose 1D Plot Group.
2
In the Settings window for 1D Plot Group, type Tangential Electric Field, z-Component in the Label text field.
3
Right-click Tangential Electric Field, z Component and choose Line Graph.
4
In the Settings window for Line Graph, type Without Grading Rings in the Label text field.
5
Locate the Data section. From the Dataset list, choose Study 1, Without Grading Rings/Solution 1 (sol1).
6
Locate the Selection section. From the Selection list, choose Shed Surface.
7
Locate the y-Axis Data section. In the Expression text field, type es.tEz.
8
In the Unit field, type kV/cm.
9
Locate the x-Axis Data section. From the Parameter list, choose Expression.
10
In the Expression text field, type z.
11
Click to expand the Legends section. Select the Show legends checkbox.
12
From the Legends list, choose Manual. In the table, enter Without grading rings.
13
Right-click Without Grading Rings and choose Duplicate. In the Settings window for Line Graph, type With Grading Rings in the Label text field.
14
Locate the Data section. From the Dataset list, choose Study 2, With Grading Rings/Solution 2 (sol2).
15
Click to expand the Title section. From the Title type list, choose None.
16
Locate the Legends section. In the table, enter With grading rings.
17
In the Model Builder window, click Tangential Electric Field, z Component.
18
In the Tangential Electric Field, z Component toolbar, click Plot . The resulting plot is shown below.
Comparison of the z component of the tangential electric field along the surface of the first six sheds from the line end without and with grading rings.
The above figure shows that the inhomogeneity and the maximum of the field are greatly reduced with the installation of the grading rings. In this way, the grading rings help the insulator to withstand a higher overvoltage and thus improve the external insulation of the power system.