温度对套管环氧胶浸纸绝缘频域介电响应的影响研究

Effects of Temperature Environment on the Dielectric Properties of Epoxy/Paper Composites for Bushing

为研究温度对环氧胶浸纸绝缘套管频域介电响应特性的影响,开展了环氧胶浸纸绝缘样片在高低温(10℃~120℃)循环下的频域介电谱测试,绘制了不同循环次数下环氧胶浸纸绝缘样片的频域介电响应特性曲线。结果表明:随着高低温循环次数的增加,在120℃时介质损耗因数、复合电容实部和虚部频谱曲线整体向上和高频方向移动,在10℃时在高频区域下介质损耗因数和复合电容虚部的频谱曲线整体向上移动,而复合电容实部的频谱曲线基本保持不变。10℃和120℃频域谱曲线的变化是由于高低温环境限制了环氧胶浸纸单位体积内带电粒子响应速度而造成电导极化作用差异性导致的,而频域谱中高频域的频谱曲线向上移动是由于高低温循环环境使得皱纹纸的纤维素长链裂解和环氧胶的环氧分子分解,致使其内部的极化损耗作用加强导致的。研究结果可为干式环氧胶浸纸绝缘套管状态评估提供一定理论基础。

In order to study the effect of temperature on the properties of frequency domain dielectric spectroscopy(FDS) about epoxy resin-impregnated paper(ERIP) insulation of bushing,the FDS test is conducted on the ERIP samples under high-low temperature(10 ℃~120 ℃) cycles,and the FDS curve for the ERIP samples under different cycles had been drawn.The results show that with the increase in the number of high-low temperature cycles,the FDS curve of the tanδ and the complex capacitance move upward and toward higher frequency at 120°C,and the FDS curve of the tanδ and the imaginary parts of complex capacitance move upward as a whole at 10 ℃,while the curve of the real parts of complex capacitance remains basically unchanged.The reason of FDS curve changes between 10°C and 120°C is that the high-low temperature environment limits the response speed of charged particles per unit volume of the ERIP and the response speed causes the difference of the electron displacement polarizability.The upward shift of the spectrum curve in the high-frequency domain is caused by the strengthen of the conductivity loss,because the cellulose long chain of the crepe paper to be decomposed and the epoxy molecules of the epoxy glue to decompose can be affected by the the high-low temperature cycle environment.The results of the study can provide a theoretical basis for the evaluation of the ERIP insulation state of the graded bushing.