采用介质损耗表征聚酰亚胺薄膜老化特征的研究

对聚酰亚胺薄膜进行电、热及电-热联合老化,测试了老化前后试样的tanδ和试样电容随试验电压的变化趋势,分析了不同老化条件对tanδ和电容的影响。实验结果表明,试样电容随不同老化条件变化的物理过程与介质损耗实验结果的分析是一致的电老化对tanδ的影响最大,热老化在一定程度上起了热清洗的作用,导致老化后介损反而降低。通过介电频谱分析,tanδ随频率变化曲线上的峰值点可以确定绝缘的老化状况。

Study on Aging Characteristics of Polyimide Film Based on Dielectric Loss

In this paper, accelerated aging test was conducted on polyimide film under the conditions of electrical, thermal and electrical-thermal stresses. In the period of aging, tanand sample capacity were measured under different testing voltages to investigate influence of tanand capacity under different aging additions. Experimental result indicated that the physical process of capacity with aging time was identical with analysis of experimental result of dielectric loss. Electrical aging plays the most important role in affecting tan, and thermal aging leaded to decreasing of tanas the function of thermal cleaning in some degree. According to dielectric spectrum analysis, it was suggested that the peak point of tancurve under different frequency could be used to describe the aging characteristics of insulation.