固体绝缘中气隙尺寸对局部放电过程的影响

为了分析和评估固体绝缘中气隙缺陷局部放电的危害,提高局部放电检测的工程应用水平,试验研究了固体绝缘单一气隙缺陷模型;测量了不同模型试品的局放起始电压、起始放电量及放电信号波形;分析了固体绝缘内部气隙缺陷的几何尺寸对局放特性的影响;考察了不同几何尺寸缺陷放电的发展过程和脉冲电流波形特征,发现不同尺寸缺陷结构的放电特性有所差异;归纳了不同场强下气隙放电的变化规律。试验结果表明,气隙缺陷尺寸越大,越易产生放电且放电量越大,外施场强增加则放电量增大,而固体绝缘中的局部放电随气隙缺陷尺寸变化表现出有差异的波形特征。

Influence of Void Dimensions on Partial Discharge in Solid Insulation

In order to analyze and evaluate the danger of partial discharge of void defect discharge in solid insulator,this paper establishes a model of common void defect discharge in solid insulation,and investigates development and pulse waveform of discharge in void with different dimensions.It is found that discharge characteristics of defects are different each other,and discharge rules under different electric field are concluded,and void partial discharges in solid insulation have similar waveform characteristics.However,when the void dimension becomes larger,special discharge pulse waveforms appear.Analysis indicates that the larger void defect dimension is,the easier discharge appears.Once discharge occurs,discharge quantity is closely linked with void dimension,which is in direct proportion with discharge quantity.Electric field can also affect discharge quantity,which is in direct proportion with electric field at the beginning,after applied electric field lasting for several minutes,they seem to be in inverse proportion.Discharge pulse waveforms in voids with different dimensions possess different characters.