基于连续型回复电压极化谱的油纸绝缘老化研究

Research on the aging of oil-paper insulation based on continuous return voltage polarization spectrum

针对传统的实际测量获取的回复电压极化谱不能准确反映各个充电时间下的回复电压情况并且中心时间常数难以准确判定的问题,提出一种连续型回复电压极化谱的绘制方法。首先对回复电压曲线、绝缘系统等效电路参数之间的关系进行理论分析;然后搭建连续型回复电压极化谱模型,提取更加准确的中心时间常数,并结合中心时间常数与变压器微水含量之间的内在联系判定变压器微水含量;最后对6台不同老化状态下的变压器进行连续型回复电压极化谱分析。研究结果表明:连续型回复电压极化谱能够更加准确判定中心时间常数,从而有效提高变压器微水含量的判定精度,为准确地反映变压器油纸绝缘老化状态提供新的方法。

To address the issues of inaccuracies in traditional return voltage polarization spectrum,specifically the inaccurate representation of return voltage at various charging times and the challenge in determining the central time constant precisely,this paper proposes a novel drawing method of the continuous return voltage polarization spectrum.Firstly,this paper analyzes the relationship between the return voltage curve and the equivalent circuit parameters of the insulation system.It then builds a continuous return voltage polarization spectrum model,extracting a more accurate central time constant.By linking this central time constant with the micro-water content of the transformer,the paper establishes an effective method for determining the transformer’s micro-water content.Finally,this paper analyzes continuous return voltage polarization spectra using six transformers in different aging states.The results show that this method accurately determines the central time constant,significantly enhancing the accuracy of micro-water content determination in transformers.This approach offers a new method to accurately assess the aging state of transformer oil-paper insulation.