油纸绝缘老化程度与电荷运动频域参量的定量关系

In order to fully understand the micro- mechanism of the frequency domain dielectric spectroscopy and to carry out effective aging evaluation for the oil-paper insulation through related physical parameters, based on related theories in Dielectric Physics, the present study expounds the corresponding relationship between the frequency domain spectroscopy and material's inner micro charge motion law under the alternating electric field. We propose the spectrum decomposition method which comprehensively considers the real and imaginary parts of the complex permittivity and effectively separate the different charge motion processes reflected by the dielectric response curve in the wide frequency band. Further, by measuring the dielectric response curves of a series of oil paper insulation samples with different aging degrees, the above method effectively reveals the change law of dielectric processes such as charge conductivity and polarization with the aging of the materials. Then we obtain the characteristic parameters with specific physical meanings to realize the quantitative aging evaluation. At the end of the paper, the function models of characteristic parameters and material's degree of polymerization are fitted, and the relevant experiment verifies the proposed method.