温度对发电机主绝缘频域介电响应的影响研究

发布时间：2018-04-16 10:02

本文选题：发电机 + 温度　；参考：《中国电机工程学报》2017年03期

【摘要】：为研究温度对大型发电机主绝缘频域介电响应的影响,将频域介电谱技术用于发电机主绝缘老化状态的无损诊断,在不同温度下进行发电机线棒试样的频域介电谱测试,基于双弛豫Cole-Cole模型,分析了温度对环氧云母绝缘频域介电谱特性的影响。结果表明:随着温度升高,复介电常数实部??和虚部??的频谱曲线整体向上和向高频方向偏移;在-103~103Hz范围内,双弛豫Cole-Cole模型可以准确描述发电机主绝缘的频域介电谱;温度升高加强了界面极化强度和偶极子转向极化强度,在虚部??频谱内,界面极化弛豫起主导作用的频率范围变宽;不同温度下的界面极化弛豫时间常数和直流电导率满足Arrhenius方程。根据过渡态理论,计算得到界面极化弛豫对应的活化焓为103.1k J/mol;活化熵随温度升高而增大,表明绝缘体系有序性减小;活化能减小,表明各种极化过程更易完成。因此可用过渡态理论解释发电机主绝缘频域介电谱的温度依存性。
[Abstract]:In order to study the effect of temperature on the dielectric response of the main insulation of large generators in frequency domain, the frequency domain dielectric spectrum technique was applied to the nondestructive diagnosis of the aging state of the main insulation of the generator, and the frequency domain dielectric spectra of the generator wire rod samples were measured at different temperatures.Based on the double relaxation Cole-Cole model, the influence of temperature on the dielectric properties of epoxy mica insulation in frequency domain is analyzed.The results show that the complex permittivity increases with the increase of temperature.And the empty part?In the range of -103 ~ 103Hz, the double relaxation Cole-Cole model can accurately describe the frequency domain dielectric spectrum of the generator's main insulation, and the temperature rise strengthens the interfacial polarization intensity and the dipole turning polarization intensity in the imaginary region.In the spectrum, the frequency range of the interfacial polarization relaxation is widened, and the interfacial polarization relaxation time constant and DC conductivity satisfy the Arrhenius equation at different temperatures.Based on the transition state theory, the activation enthalpy corresponding to the interfacial polarization relaxation is calculated to be 103.1 k / mol. The activation entropy increases with the increase of temperature, indicating that the order of the insulation system decreases and the activation energy decreases, indicating that the various polarization processes are easier to complete.Therefore, the transition state theory can be used to explain the temperature dependence of the dielectric spectrum in the frequency domain of the main insulation of the generator.
【作者单位】：西南交通大学电气工程学院;
【基金】：国家自然科学基金项目(51177136)~~
【分类号】：TM31

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