中文摘要：

随着电力设备电压等级的提高,对电力设备中聚合物电介质材料的可靠性提出了更加严格的要求,然而由于聚合物电介质材料在生产制造过程中不可避免的存在气泡、杂质等缺陷,导致在高电场作用下会发生局部放电从而大大降低了电力设备的使用寿命.因此,为了预防和减少电力设备中因聚合物电介质材料老化所带来的事故,需要合理地估算其电老化寿命.本文从局部放电老化模型的微观机理出发,利用非平衡态统计理论建立了电裂纹不断扩展的随机微分方程,然后推导出聚合物电介质的击穿概率、可靠性以及电老化寿命与外加电场的函数关系.最后,对聚苯二甲酸乙二醇酯（polyetllyleneterephthalate,PET）薄膜材料进行具体分析,将电老化寿命公式的理论值与实验数据作了比较,发现实验数据与理论值较为相符.因此,本文推导的聚合物电介质电老化寿命公式可以有效地应用在定量分析中,并有望为材料的电寿命预测提供帮助.

英文摘要：

With the improvement of voltage level of electrical equipment, the requirement for the reliability of polymer dielectric materials in electrical equipment is much more strict. However, there are inevitably some defects in the manufacturing process of polymer dielectric materials, such as bubbles, inclusions, and so on. Therefore the life of electrical equipment will be greatly decreased when partial discharge occurs in a high electric field. In order to prevent and reduce the accident caused by the aging of polymer dielectric material in the electrical equipment, electrical aging life needs to be reasonably estimated. Based on the microscopic mechanism of partial discharge aging model, this paper suggests a stochastic differential equation for the electrical crack growth by using a non-equilibrium statistical physics theory, and then functions of breakdown probability, reliability, and electrical aging life due to the application of electric field are derived. Finally, a detailed analysis for the polyetllyleneterephthalate （PET） film is carried out, and the theoretical life of electrical aging is compared with experimental data. Results show that the theoretical values are consistent with the experimental data. So the aging life equations of polymer dielectrics derived in this paper can be used effectively in the quantitative analysis and may be helpful for the estimation of electrical life.