变压器油纸绝缘状态的FDS法测试及特征量分析

FDS Method Test and Characteristic Quantity Analysis of Transformer Oil Paper Insulation State

为达到确定变压器内绝缘频域参数与特征参量之间关系的目的,对油浸式电力变压器油纸绝缘系统开展频域测试。在不同温度时对样品进行热老化处理。另外,对样品开展频域介电谱(FDS)测试法研究,设定模型参数,拟合得出其与老化时间、试验温度的关系。研究结果表明,在老化时间和试验温度发生改变时,FDS参数tanδ和ε′在高低频率范围均表现为逐渐减小,达到拐点后缓慢上升,且拐点缓慢平移至高频区域;提取Davidson-Cole模型参量β、Δε、τ,通过拟合,得到模型参量和老化时间、试验温度之间的函数关系。该研究为变压器油纸绝缘老化水平的评估提供新的方向。

Frequency domain tests are carried out on oil-paper insulation systems of oil-immersed power transformers for the purpose of determining the relationship between frequency domain parameters and characteristic parameters of the inner insulation of the transformer.The samples are subjected to thermal aging at different temperatures.In addition,frequency dielectric spectroscopy(FDS)tests are performed on the samples,and the model parameters are set and fitted to determine the relationship with aging time and experimental temperature.The study shows that the FDS parameters tanδandε′decrease gradually in the high and low frequency range when the aging time and experimental temperature are changed,and increase slowly after reaching the inflection point,and the inflection point is slowly shifted to the high frequency region;the Davidson-Cole model parametersβ、Δε、τare extracted and fitted to obtain the relationship between the model parameters and aging time and experimental temperature.The research provides a new direction for the evaluation of the aging level of transformer oil paper insulation.