Development of Smart Silicone Rubber Insulating Materials for HVDC Transmission Systems

高压直流输电系统智能硅橡胶绝缘材料的开发

• 批准号: RGPIN-2018-04409
• 负责人: Ghunem, Refat
• 金额: $ 2.04万
• 依托单位: École de technologie supérieure
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754442
• 关键词: Development; Smart; Silicone; Rubber; Insulating

Silicone rubber insulators have shown excellent pollution performance and thus have been replacing the conventional insulators made from porcelain or toughened glass in alternating current (AC) overhead power transmission systems. These insulators are also recommended for use in high voltage direct current (HVDC) transmission line systems, with a few changes made in the geometry but with no consideration given to the housing material design. Modifying the geometry by increasing the creepage distance may ensure an acceptable flashover performance over the short term, but aging remains an issue of a great concern. In the light of the increased application of HVDC links in the electricity grid, this concern has driven an interest in developing reliable silicone rubber insulation housing materials for HVDC systems. Conventional silicone rubber housing materials have been developed based on more than 50 years of industry experience in AC insulators. But, this experience-based approach cannot be applied in the development of DC insulators as experience is limited in insulator aging under DC voltages. This research program proposes the development of reliable, cost-effective, and thus smart, silicone rubber housing materials for DC outdoor insulation applications in a mechanistic-based framework. The following projects are executed under the proposed research program. (1) Erosion Mechanisms: erosion of silicone rubber insulators as a result of dry-band arcing induced on the surface of the housing material is a critical aging mechanism leading to insulation failure in polluted service condition. The dynamic nature of the DC as compared to the AC dry-band arcing is studied in order to develop an electro-thermal model for the dry-band arcing as a heat source, impinging the surface and causing heat ablation. (2) The Role of Inorganic Fillers: Traditionally, housing material composites are loaded as much as possible with inorganic fillers. Inorganic fillers, as flame retardants, suppress the formation of carbonaceous tracks as a result of dry-band arcing causing decomposition of the surface. However, silicone rubber is tracking-resistant and thus erosion is of a concern. In this project, the erosion suppression effects of inorganic fillers are investigated. Emphasis will also be given to understand role of interface as nano-sized fillers are employed. Accordingly, a thermal model is developed to predict the erosion performance of composites formulated for DC outdoor insulation using inorganic fillers. (3) Material Screening Methods: In response to a great demand raised by insulator manufacturers and utilities, a material screening method for the qualification of erosion resistance of DC outdoor insulating materials is developed to provide reproducible outcomes that correlate with the actual performance in service.

硅橡胶绝缘子具有优异的抗污染性能，已逐渐取代传统的瓷绝缘子或钢化玻璃绝缘子用于交流架空输电系统。这些绝缘体也被推荐用于高压直流（HVDC）输电线路系统，在几何形状上做了一些改变，但不考虑外壳材料的设计。通过增加爬电距离来改变几何形状可以在短期内确保可接受的闪络性能，但老化仍然是一个非常值得关注的问题。随着高压直流输电系统在电网中的应用越来越多，这一问题引起了人们对开发可靠的高压直流输电系统硅橡胶绝缘外壳材料的兴趣。传统的硅橡胶外壳材料是基于50多年的交流绝缘子行业经验而开发的。但是，这种基于经验的方法不能应用于直流绝缘子的开发，因为在直流电压下绝缘子的老化经验有限。这项研究计划提出了可靠的，具有成本效益的，因此智能的硅橡胶外壳材料的开发，用于直流室外绝缘应用在一个基于机械的框架。下列项目在拟议的研究计划下执行。(1)冲蚀机理：硅橡胶绝缘子在受污染的使用条件下，由于外壳材料表面产生干带电弧而产生的冲蚀是导致绝缘子失效的关键老化机理。研究了直流干带电弧与交流干带电弧的动态特性，建立了干带电弧作为热源撞击表面并引起热烧蚀的电热模型。(2)无机填料的作用：传统上，房屋材料复合材料尽可能多地加载无机填料。无机填料，作为阻燃剂，抑制由于干带电弧引起的表面分解而形成的碳质轨迹。然而，硅橡胶是抗跟踪的，因此腐蚀是一个问题。本课题研究了无机填料的抗冲蚀效果。重点还将给予理解界面的作用，纳米尺寸的填料的使用。因此，建立了一个热模型来预测使用无机填料配制的直流室外绝缘复合材料的侵蚀性能。(3)材料筛选方法：为响应绝缘子制造商和公用事业公司提出的巨大需求，开发了直流室外绝缘材料耐冲蚀性鉴定的材料筛选方法，以提供与实际使用性能相关的可重复性结果。