300MW汽轮发电机主绝缘老化诊断

Aging Diagnosis for 300 MW Turbo-generator Stator Insulation

介绍谏壁发电厂300MW汽轮发电机定于绝缘老化诊断的研究结果、采用新的检测方法对试验线棒进行了介质损耗、交流电流和局部放电测量，并用介质损耗增长率△2、电容增长率△C″、局部放电损耗指数PDI，交流电流增长指数m2、局部放电统计参量的偏斜度Sk和UWB放电脉冲的能量分布等特征参量对测量结果进行分析，同时采用扫描电镜对试验线棒的微观结构进计观察。结果表明，发电机主绝缘老化比较严重，新提出的特征参量较传统的评估参量更能有效地表征发电机主绝缘的老化状态。

The diagnostic results for 300 MW turbo-generator stator insulation in Jianbi Power Plant are reported. Novel methods are used to measure the dielectric dissipation factor, AC leakage current and partial discharge parameters of the stator insulation. Some characteristic parameters, such as dielectrie dissipation incremental rate △2, capacitance incremental rate △C″, dissipation index of partial discharge PDI, secondary AC current rapid increase index m2, skewness of statistical parameters of partial discharge Sk, and the energy distribution of UWB partial discharge pulse etc. are employed to analyze the experimental data. In addition. the scanning electronic microscope is applied to observe the microstructure of the stator insulation. It is concluded that the aging condition of the stator insulation is serious and the novel characteristic parameter proposed in this paper can be effectively used to characterize the aging degree of large generator stator winding insulation as compared with traditional parameters.