SF

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gas insulated current transformer is widely used in power system thanks to its simple structure and perfect insulation performance and is the main equipment for protection and measurement of power grid.It is of great significance to analyze the fault causes of current transformer for maintaining power grid security.In this paper

the insulation breakdown phenomenon of a 500 kV SF

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current transformer is studied

the structure of the current transformer is analyzed

the dielectric model is established and the electric field is calculated.The rheological electric field strength of self-made coat

Axicom coat and other domestic structures are comparedand the fault causes are analyzed.Finally

it is concluded that the d

ischarge of SF

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current transformer is due to unreasonable rheologic al intern al insulation margin

which can provide reference for design optimization

fault diagnosis and operation maintenance of the same type of gas insulated current transformer.