SF6气体低温下典型缺陷的局部放电特性研究OA

Aiming at the problem that the change of SF6 gas state affects the partial discharge of equipment,a partial discharge test platform of SF6 gas at low temperature is built to explore the partial discharge initiation voltage and partial discharge development characteristics of SF6 gas in surface discharge,tip discharge and suspension discharge models under different pressure and temperature conditions from-50℃to 20℃are investigated.The test results show that the partial discharge initial voltage and discharge amplitude of the three models show a hump-shaped trend with temperature change.For the surface discharge and suspension discharge models,when the temperature decreases from 20℃to 0℃,the partial discharge initial voltage and discharge amplitude show a slight upward trend with the decrease of temperature.When the temperature decreases from 0℃to-50℃,both of them show a downward trend under the influence of intermolecular Van Der Waals force.Among the three models,the temperature drop has the most significant effect on the partial discharge initial voltage of the surface discharge model,with a maximum of 64.3 kV and a minimum of 25.3 kV,and the decrease is about 60.6%.