聚合物绝缘材料多因子老化的研究现状与发展

Status and Progress in Multi-factor Ageing Research for Polymer Insulation Materials

聚合物绝缘材料在电、热、机械等多种应力作用下会发生老化而导致绝缘性能下降,研究聚合物绝缘材料在多应力因子老化的理论及试验方法,对于预测剩余寿命和指导绝缘设计具有重要意义。首先对多因子老化的唯象和物理寿命模型进行了梳理和对比,其次对多因子老化的试验方法进行了总结;然后简单讨论了协同效应在多因子老化中的作用;最后对聚合物材料多因子老化研究的发展趋势进行了讨论分析。寿命模型的对比表明,基于化学反应速率理论的电-热寿命模型适用于较低电场下,热应力为主的老化情况,基于失效概率理论的电-热寿命模型适用于较高电场下,电应力为主的老化情况;相比于唯像模型,物理模型考虑了材料的微观结构特性和具体老化机制,在预测剩余寿命和指导绝缘设计方面具有优势。以后的多因子老化研究中,应重点研究不同应力间的协同效应,及其引起的新的老化机制,将材料老化过程中宏观性能的变化和微观结构和物理机制联系起来,建立物理意义明确的寿命模型。

Polymer insulation materials are aged under various stresses such as electric field, heat and mechanical force, resulting in degradation of insulation performance. The study of theory and test methods for aging of polymer insulation materials under multiple stress factors is of great significance for residual life prediction and insulation design. In this paper, firstly, the phenomenological and physical life models of multi-factor aging were carded and compared. Secondly, the test methods of multi-factor aging were summarized. Then the role of synergistic effects in multi-factor aging was briefly discussed. Finally, the development trend of multi-factor aging research for polymer materials was analyzed. Comparison of the life models shows that the electro-thermal life model based on chemical reaction rate theory is suitable for the aging condition dominated by thermal stress at lower electric field. The electro-thermal life model based on failure probability theory is suitable for the aging process due to higher electric field. Compared to the phenomenological model, the physical model takes into account the microstructural characteristics of materials and specific aging mechanism, having advantages in residual life prediction and insulation design. In future multi-factor aging study, focus should be put on the synergistic effects between different stresses causing a new aging mechanism, and the link of the macroscopic performance changes with microstructure and physical mechanisms in the aging process of materials, to establish life models with clear physical meaning.