回复电压微分谱线特性的变压器绝缘老化研究

Insulation aging of transformer based on recovery voltage differential spectrum line characteristic

针对油纸绝缘变压器老化会对其等效电路产生影响,通过分析回复电压谱线与等效电路参数的函数关系,提出回复电压微分解谱法确定等效电路极化支路数,解决了长期以来变压器等效电路极化支路数难以确定的问题,为准确诊断变压器绝缘状态奠定重要基础。通过实例验证表明:利用回复电压微分解谱法能够准确判定等效电路的极化支路数,能更准确地反映变压器绝缘老化状况,且变压器绝缘老化越严重,其回复电压微分谱线子谱线个数和等效电路的极化支路数越多。

To avoid the impact of oil-paper insulation transformers＇ aging on its equivalent circuit, the recovery voltage differential spectrum solution method is proposed to determine the number of equivalent circuit＇ s polarization branches by analyzing the functional relation between the recovery voltage spectrum line and the parameters of the equivalent circuit. The proposed method solves the long-time knotty problem in determining the number of polarized branches of the equivalent circuit, laying a solid foundation for diagnosing the insulation state of the transformer accurately. Case studies show that the number of polarization branches of the equivalent circuit can be determined accurately and the insulation aging condition of the transformer is reflected more accurately by using the recovery voltage differential analysis method. Moreover, the number of the differential spectrum lines and polarization branches becomes larger when the transformer insulation aging becomes worse.