考虑线型因子的变压器油纸绝缘系统微水含量评估

Evaluation on micro water condition of transformer insulation considering line shape factor

针对现有的时域介质响应方法无法直观诊断变压器受潮情况,现从微观动力学的角度分析线型因子与微水含量的内在联系。提出的时域微分解析法将隐含在去极化电流曲线中的不同介质极化过程逐一分解,不但可求得线型因子,而且能直观地判断弛豫项数。通过对变压器测试曲线的解析结果表明,变压器的受潮程度与弛豫项数相关及线型因子有密切联系:弛豫项数越多,绝缘系统内部微水含量越多;绝缘系统受潮越严重,表征绝缘纸极化的线型因子越大。

The relation of line shape factor and micro water condition from the perspective of microscopic dynamics is analyzed for damp condition of transformer not being evaluated directly by conventional time domain dielectric response method.The different dielectric polarization processes hidden in the polarization current were resolved individually by the proposed time-differential method.The method not only solved the line shape factor,but also determined the number of relaxations directly.The results on analysis of transformer test curves shows that the damp condition is related to the number of relaxations and line shape factors closely.The larger number of relaxations,the more micro water in the insulation.The damp condition goes worse when line shape factors increase.