变压器极化谱特征量与绝缘状态关系研究

Study on the relationship between polarization spectrum characteristic quantity and insulation condition of oil-paper transformer

油纸变压器绝缘介质特性复杂,为了研究绝缘介质弛豫响应与油纸绝缘时域极化谱特征量的内在关系,以便将电气特征量法应用于无损诊断变压器绝缘状态,通过建立变压器油纸绝缘等效电路模型,仿真分析了回复电压极化谱特性,并在仿真基础上研究了不同绝缘状态下油纸绝缘时域极化谱特征量变化规律。结论表明,时域响应回复电压极化谱特征量能有效评估油纸变压器绝缘状态的差异,测试结果验证了等效电路模型对绝缘系统极化过程的有效反映,分析出电路参数仿真变化对应的回复电压特征量变化规律,为运用回复电压测试技术无损诊断变压器绝缘状态奠定了理论基础。

The insulation dielectric characteristic of oil-paper transformer is complex.In order to study the inherent relationship between the time-domain polarization spectrum characteristic quantity of oil-paper insulation and the insulation dielectric relaxation response,the electrical characteristic measurement method was applied to the non-destructive diagnosis of the transformer insulation condition.The equivalent circuit model of transformer oil-paper insulation was established and the return voltage polarization spectral characteristic was analyzed in simulation; based on the simulation,the variation law of the time-domain polarization spectrum characteristic quantity of oil-paper insulation was investigated under different insulation conditions.Results show that the polarization spectrum characteristic quantity of the time-domain response return voltage can be used to effectively estimate the insulation condition of the oil-paper insulation transformer.The experiment results validate that the equivalent circuit model can effectively reflect the polarization process of the insulation system.The change rule of the return voltage characteristic quantity with the circuit parameters is analyzed and obtained in simulation,which lays a theoretical foundation for the non-destructive diagnosis of transformer insulation condition using return voltage measurement（ RVM） technique.