高压绝缘纳米复合材料强电场下的力电行为研究

Research and development of high-performance insulating materials are of great significance for developing ultrahigh-voltage DC transmission. However, space charge accumulation and electrical ageing have become bottleneck of this kind of materials. Although the recent experiments have demonstrated nanocomposite an effective approach to break this bottleneck, research on the mechanism for suppression of space charge and electrical ageing by addition of nanoparticles is still lack, which restricts the design, fabrication and application of new materials. Therefore, in this project, we will study systematically the mechanical and electrical behaviors of high-voltage insulating nanocomposites under strong electric field. An approach combining atomic scale simulation and space charge dynamics will be creatively proposed and a computational model for space charge distribution in nanocomposites will be established. By embedding the electrical tree growth criterion into finite element code, a three-dimensional numerical simulation technology for electrical tree growth in high-voltage insulating nanocomposites will be developed. A theoretical model for driving energy of electrical ageing will also be established by considering space charge and nanoparticle as two inclusion phases in the composites. Besides, an approach for micro-scale electro-mechanical coupling experimental characterization of high-voltage insulating nanocomposites will be developed. Through the aforementioned study, the mechanism for suppression of space charge and electrical ageing by addition of nanoparticles will be revealed, and the characterization parameters and evaluation system of the material performance will be established, which can guide the optimal design of high-voltage insulating nanocomposites.

高性能绝缘材料的研发，是发展特高压直流输电技术的关键，而绝缘聚合物的空间电荷积聚和电老化则是制约其发展的主要瓶颈。最新实验表明，纳米复合材料是克服这一瓶颈的有效途径，然而，关于纳米颗粒对空间电荷和电老化抑制机理的研究则十分缺乏，严重制约了新材料的设计、制备与应用。因此，本项目将系统地研究高压绝缘纳米复合材料强电场下的力电行为。创新地提出将原子尺度模拟与空间电荷动力学计算相结合，建立纳米复合材料中空间电荷分布的计算模型；将电树枝生长判据嵌入有限元，开发高压绝缘纳米复合材料电树枝生长的三维数值模拟技术；建立考虑空间电荷和纳米颗粒双夹杂相复合材料中电老化驱动能的理论模型；发展高压绝缘纳米复合材料的微观力电耦合实验表征方法。通过研究，揭示纳米颗粒抑制空间电荷积聚和电老化的机理，建立材料性能表征参量及其评价体系，指导高压绝缘纳米复合材料的优化设计。

高性能绝缘材料的研发，是发展特高压直流输电技术的关键，而绝缘聚合物在强电场下的的空间电荷积聚和失效破坏问题则是制约其发展的主要瓶颈。纳米复合材料是克服这一瓶颈的有效途径。通过项目的执行，建立了强电场下高压绝缘纳米复合材料中空间电荷演化的动力学模型，探讨了高压绝缘纳米复合材料强电场下失效破坏行为的主要影响因素，搭建了高压绝缘纳米复合材料的测试设备，发展了相应的实验表征技术。最终以上述理论成果与实验技术为基础，提出了高压绝缘纳米复合材料的优化设计方法，为材料的实际工程应用与工艺参数改进提供指导。