62 / 2018-08-21 16:35:28

FEM Analysis on the Distribution of Internal Radial Voltage along 800kV DC Voltage Divider

DC voltage divider; resistance-capacitance unit; radial voltage; non-uniform polluted and wet condition; shed bridged by rain

As the different electrical potential between internal resistance-capacitance unit and outdoor insulation, the radial voltage between resistance-capacitance unit and the hollow insulator. the In order to find out the relationship between the internal radial voltage of DC voltage divider and the surrounding environment, a FEM (Finite Element Method) analysis were carried out by the example of 800 kV DC voltage divider with composite housing. The internal radial voltage of DC voltage divider under the dry condition, un- and even wet and polluted conditions, and heavy rainy condition was calculated. The simulation results show that the maximum radial voltage of the DC divider subjected to dry condition was about 60kV located at the second resistance-capacitance unit near the high voltage terminal. For the case of wet and polluted condition, the radial voltage was about 3kV larger than that in the case of dry condition. When heavy rain and part of the sheds of the composite housing were bridged by the rain, the maximum radial voltage increased, and the displacement was related to the length and location of the sheds bridged. With the increased internal radial voltage, the voltage divider will run the high risk of radial discharge. Thus then the radial voltage under different environment conditions were strongly recommended to consider in the insulation design of DC voltage divider.