Method for obtaining potential distribution of 800kV direct current bus metallic oxide arrester

Abstract

The invention discloses a method for obtaining potential distribution of an 800kV direct current bus metallic oxide arrester. The method comprises the steps of (1), simulating the potential distribution when the metallic oxide arrester operates normally, wherein the step (1) comprises the sub-steps of (1-1), establishing a three-dimensional mathematical model for the potential distribution of the metallic oxide arrester, (1-2), assigning resistivity according to a material attribute of each component of the metallic oxide arrester, and (1-3), applying a forced potential boundary condition; and (2), carrying out resolution calculation on the three-dimensional mathematical model according to the assigned resistivity and the forced potential boundary condition, thereby obtaining the potential distribution when short circuits occur in resistors at different positions or the resistors are damped. According to the method, the complete three-dimensional model of the 800kV direct current bus zinc oxide arrester is established according to the actual size parameter of each component of the arrester; the periphery space of the arrester is simulated through a limited air domain; the potential of a suspension conductor is processed through utilization of degree of freedom coupling in ANSYS; a calculation scale is simplified; and moreover, the potential distribution of the arrester is calculated accurately.

Description

technical field [0001] The invention belongs to the technical field of state monitoring and fault criterion of UHV DC arresters, and more specifically relates to a method for obtaining the potential distribution of metal oxide arresters for 800kV DC busbars. Background technique [0002] The ±800kV UHV DC transmission has no landing point in the middle, and can directly send a large amount of power to a large load center. It has the advantages of large transmission capacity, long transmission distance, and saving transmission and wiring corridors. The construction of the UHV DC transmission system is inseparable from the overvoltage protection device, and the surge arrester is the main equipment for overvoltage protection, the basis of the grid insulation coordination and the guarantee of reliable operation, and its insulation performance is directly related to the UHV DC Stability of transmission system operation. [0003] Since the DC bus surge arrester adopts a complex s...

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Problems solved by technology

[0003] Since the DC bus surge arrester adopts a complex structure of multi-column parallel connection and multi-section series connection of resistive plates, it will gradually age or deteriorate under the influence of normal working voltage, various internal overvoltages, lightning overvoltages and external environmental factors for a long time. The phenomenon of moisture in the arrester and unreasonable voltage distribution caused by poor sealing will cause safety accidents and endanger the safe and stable operation of the DC transmission system if not paid attention to

[0004] At present, the research on the potential distribution of metal oxide arresters is mostly carried out for AC arresters. The potential distribution under the continuous operating voltage of AC is regarded as an electrostatic field problem, that is, the voltage is distributed inversely proportional to the dielectric constant of each medium, but the DC operating voltage The electric field below does not satisfy this law

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