Improvement of Mechanical and Electrical Strength of the Cap-and-Pin Type String Insulators

电力传输系统的功能和可靠性在很大程度上取决于绝缘体，绝缘体将导体与其他导体、塔和地面隔离开来。绝缘体承受长时间的高机电应力。绝缘子必须长期保持其物理性能和机械强度而不变质。绝缘体的优良性能是选用合适的材料、合理的设计和现代化的制造技术的结果。绝缘子的机械特性和电气特性受静态机械负荷（悬浮或拉力）、动态机械负荷（短路、风和导体飞驰）、温度和强电场的影响。机械负荷、温度和强电场会使绝缘子的性能下降，从而影响输电线路系统输送电力的质量和可靠性。理想情况下，应定期检查输电线路绝缘子，以确保最大限度的服务可靠性。然而，由于大量的绝缘子在使用中（例如，在北美超过1.5亿个瓷绝缘子），这对公用事业公司来说是不切实际的。改进绝缘子设计，使其耐用，延长使用寿命，多年来一直是人们感兴趣的话题。通过提高绝缘体的机械强度、热强度和电强度，可以提高绝缘体的耐压能力。拟议研究项目的目的是与Powertech高压实验室合作，采用一种基于有限元法和标准化电气和机械测试方法的高压绝缘体设计新方法。这项研究的结果将为绝缘体提供优化设计，从而提高其机械和电气承受能力。改进后的设计将提高Powertech实验室在高压绝缘体制造行业的竞争力和存在感。

Functionality and reliability of electric power transmission systems highly depend on insulators that isolate conductors from each other, the towers, and the ground. The insulators undertake high electrical mechanical stresses for long periods of time. The insulators must maintain their physical properties and mechanical strength over long periods without deterioration. The good performance of insulators results from using proper materials, suitable design, and modern manufacturing technology. The mechanical and electrical characteristics of an insulator are affected by the static mechanical loads (suspension or tension), dynamic mechanical loads (short circuit, wind, and conductor galloping), temperature, and high electric field. The mechanical loads, temperature, and high electric field can degrade the insulators' performance, which will compromise the quality and reliability of the electric power delivered by the transmission line system.Ideally, transmission line insulators should be inspected regularly to ensure maximum service reliability. However, due to the large number of insulators in service (e.g. over 150M porcelain insulators in North America), this is not practical for utility companies. Improvement of insulator design to make them durable for longer life of service has been a topic of interest for many years. The withstand voltage of insulators will be improved by increasing the mechanical, thermal, and electrical strength. The purpose of the proposed research project is to introduce a new method to design high voltage insulator based on finite element method (FEM) and standardized methodologies of electrical and mechanical tests in partnership with Powertech High Voltage Laboratory. The outcome of this research will provide an optimized design for insulators that will improve both their mechanical and electrical withstand. The improved design will enhance the competence and presence of Powertech Labs in high voltage insulator manufacturing industry.