绝缘油中悬移气泡局部放电特性

Characteristics of Suspended and Mobile Microbubble Partial Discharge in Insulation Oil

为了研究绝缘油中悬移气泡局部放电特性,从力学角度分析了处于不同运动状态下绝缘油中气泡的变形机理,借用椭圆的数学参数作为气泡变形特征参数c,仿真研究了气泡周围的电场分布随特征参数c变化的关系,建立了以变压器油道为背景的油中悬移气泡局部放电实验平台,采用超高频法和脉冲电流法测试了气泡静止和移动两种状态的局部放电,分析了放电的时频特性差异,构造了放电三维图谱。结果表明,随着油的流速增大,悬移气泡的形状由水平方向拉伸的椭球状变为竖直方向拉伸的椭球状,气泡沿极间电场分布减小,发生局部放电的起始电压变高,流动油有利于绝缘强度的提高。

In order to study the partial discharge （PD） characteristics of suspended and mobile microbubble in insulation oil,the deformation mechanism of microbubbles in different motion state was discussed from the viewpoint of mechanics.The deformation parameter c of microbubble was defined using mathematical ellipse parameters,the surrounding electric field distribution with the characteristic parameter c changes was analyzed,and the mode of stimulating the suspend and mobile microbubbles in transformer oil was designed.Methods of ultra-high frequency and pulsed current were used to test the partial discharge of mobile and stationary microbubble,the time-frequency characteristics of different discharge were analyzed,and three-dimensional map was constructed.The results show that with the oil flow rate increases,the ellipsoidal microbubble changes from the horizontal stretch to a vertical stretch,the electric field distribution of microbubbles between the pole decreases,and the partial discharge inception voltage is increased.Therefore,increased flow will help to improve the oil dielectric strength.