Analysis And Structure Improvement Of The3-D Electrostatic Field Of The High-voltage Isolation Grounding Module

With the rise of electricity consumption, transmission distance is getting longer and longer, the highest voltage level of the power system will be also further improved. To solve the problem of insulation on electrical equipment is becoming increasingly difficult. It is because of the increase in working voltage of the electrical equipment, its insulation materials is using more and more. The cost of the insulation on the device as a proportion of the cost is higher and higher. The size and weight of the equipment are also growing. Therefore, it put forward higher requirements for the high-voltage electrical insulation properties. Electric field numerical calculation for the study of the structural design of high voltage electrical equipment and to improve the insulation performance, has a vital role.This paper is to understand the three-dimensional electric field intensity distribution of the high-voltage GIS isolated the grounding module air chamber. Firstly, it gave a geometric model in3D modeling software, and based on the value of the electric field theory, using finite element analysis. It established ZF32-126isolated grounding module chamber mathematical model of three-dimensional electrostatic field.Then in view of the actual model complexity in the finite element software, On the basis of the intelligent meshing,analysis region, the calculation model focus conduct grid refinement and check the unit mass, it solved a series of problems in the intelligent meshing.Finally, it calculated and analysed the three-dimensional electric field strength of the gas chamber as a whole of the isolated ground module.Through analyzing the three-dimensional electric field numerical of the isolated grounding module ZF32-126, it got the whole gas chamber and the potential of the epoxy casting the insulator and the contours of electric field strength. The results show that the Gas gap is the field strength of the concentrated area, it Can be improved by changing the shape of the electrodes, or increasing the insulation gap to the electric field distribution in the region. The maximum electric field strength of SF6insulating gas in the gas chamber is less than the breakdown field strength. At the same time, the maximum of the electric field strength of the epoxy resin casting insulation pieces is lower than along the surface flashover field strength values, all of these have a certain insulating margin.Through the Frequency voltage withstand test, and lightning impulse test of theZF32-126isolated grounding module, it further verified the reliability of the insulation structure, The gas chamber as a whole does not occur breakdown phenomenon and Surface flashover phenomenon, it has good insulating properties. On the basis of numerical analysis and field tests on the insulation structure, it changed the fillet radius of the isolation switch dynamic, static contact and earthing switches dynamic and static contact in the isolated ground module chamber. And use the Matlab curve fitting functions, it improved the shape of the electrode reasonablely. Then, in order to increase the creepage distances of the disc insulator and reduce the surface flashover field strength values, it designed the structure of the disc insulator, reduced the maximum electric field strength of the disc insulators.Through the numerical analysis of the three-dimensional electrostatic field of the high-voltage GIS disconnecting the grounding module, In the case of limited computer resources, it achieved the analysis of large-scale projects to use the three-dimensional electrostatic field of the switchgear.The results obtained by the numerical calculation, provides a theoretical basis for the high-voltage electrical equipment, the overall structure and internal insulation to further optimize.