Method and system for ultrahigh frequency radiation characteristic simulation of oil impregnated paper condenser sleeve end screen

Abstract

The invention provides a method for ultrahigh frequency radiation characteristic simulation of an oil impregnated paper condenser sleeve end screen. The method comprises the following steps of: building a three-dimensional model of an oil impregnated paper condenser sleeve; performing grid initialization and self-adaptive sub grid division on the three-dimensional model on the basis of a finite-difference time-domain method; setting a simulation excitation source; installing a plurality of data observation points; obtaining collecting data, in positions of the data observation points, obtained in the simulation electromagnetic wave time domain spreading process in the preset time; and performing analysis according to the collecting data to obtain the ultrahigh frequency radiation characteristic of the oil impregnated paper condenser sleeve end screen. By the simulation method, the good fitting with the engineering practice can be realized. Compared with field tests, the method is safer and has better economic performance and higher feasibility. The invention also provides a simulation system realizing the method.

Description

technical field [0001] The patent of the present invention relates to the field of simulation technology, in particular to a method for simulating UHF radiation characteristics of the end screen of an oil-paper capacitive bushing. Background technique [0002] The bushing is a main part of the transformer. The lead wire of the transformer winding is led out of the box by the bushing. The bushing plays the role of insulating and fixing the winding lead wire to the oil tank and delivering the current to the outside of the box. It needs to adapt to various external conditions. Environmental conditions, and have a certain mechanical strength. Usually, the bushings are divided into different forms such as pure porcelain bushings, oil-filled bushings, gas-filled bushings, and capacitive bushings. In order to make the radial and axial field strength of the bushing of 110kv and above uniform, the insulation structure generally adopts a capacitive type, that is, many insulating laye...

AI Technical Summary

Problems solved by technology

If the end screen is unsound or poorly grounded due to various reasons during operation, a capacitance will be formed between the end screen and the ground, and this capacitance is much smaller than the capacitance of the bushing itself. According to the principle of capacitor series, it will be between the end screen and the ground. A very high floating voltage is formed, causing the last screen to discharge to the ground, burning the insulation near the last screen, and even serious casing explosion accidents.

[0003] The existing bushing preventive test method needs to temporarily disconnect the grounding terminal of the end screen or temporarily change the grounding circuit of the end screen. The irregular operation or negligence of the on-site personnel often leads to the virtual connection of the end screen to the ground.

Another existing bushing on-line monitoring device can measure bushing dielectric loss, capacitance and other parameters online by connecting sensors in series in the grounding loop. , Improper selection of the installation position during the installation process can easily lead to virtual connection or disconnection of the end screen, resulting in continuous discharge of the end screen terminal under the operating voltage and the serious casing explosion accident mentioned above may occur

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