Advanced composite dielectric materials for use in the transmision of electrical power by direct current

标准的工业测试加上在服务中的经验通常用于开发高压交流电（HVAC）输电线路的绝缘子设计。在大多数情况下，传统的陶瓷绝缘子已经在过去100年左右的HVAC输电线路上使用。今天，由聚合物材料（聚合物绝缘体）制成的绝缘体正在逐渐取代旧的陶瓷绝缘体。聚合物绝缘体已经以这种方式开发用于暖通空调，目前在高压直流（HVDC）输电线路上使用的数量有限。鉴于全球对高压直流输电的兴趣日益浓厚，用于高压直流的聚合物绝缘体已经成为一个未知的实体，因为没有针对高压直流开发标准的工业测试。在本研究项目中，暖通空调的聚合物绝缘子使用HVAC标准测试进行了评估，但对HVDC进行了适当的修改，包括聚合物材料的适用性和绝缘子设计评估，即能够承受有利于聚合物材料老化的环境条件。研究计划将首先检查斜面测试（IPT），该测试是专门为交流开发的，并适当地修改了直流测试。这一步强调了聚合物材料在交流和直流之间老化机制的差异，并验证了交流聚合物绝缘材料在直流下的使用。高分子材料表面的电润湿机理是导致材料老化的主要因素，本文将对其在交流、+DC和-DC下的电润湿机理进行研究和比较。暖通空调绝缘子的两种常见聚合物材料，硅橡胶和乙丙二烯单体，将使用IPT在直流研究不同的填料和填料水平。直流绝缘子设计将在盐雾环境下进行研究，现有的交流绝缘子设计将在类似老化条件下用于直流绝缘子。修改绝缘体的外形和材料，以获得最佳性能，预计将是研究计划的结果。

Standard industry tests coupled with in-service experience have commonly been used to develop insulator designs for high voltage alternating current (HVAC) transmission lines. For the most part, conventional ceramic insulators have been used on HVAC transmission lines for the past 100 years or so. Today, insulators that are made from polymeric materials (polymer insulators) are gradually replacing the older ceramic insulators. Polymer insulators have been developed in this way for HVAC and are currently used in limited numbers on high voltage direct current (HVDC) transmission lines. In light of increased global interest in HVDC transmission, polymer insulators for HVDC have become an unknown entity, as no standard industry tests have been developed for HVDC. In this research program, polymer insulators for HVAC are assessed for use at HVDC using the standard tests developed for HVAC, but suitably modified for HVDC, both for suitability of polymeric material and insulator design evaluation in terms of being able to withstand the environmental conditions conducive to aging of polymeric materials. The research program will initially examine the inclined plane test (IPT) that has been developed specifically for AC and suitably modifying the test for DC. This step highlights the differences in aging mechanisms of polymeric materials, between AC and DC, and validates the use of AC polymeric insulation materials at DC. The electrowetting mechanism of surfaces, which is a major factor in aging of polymeric materials, is to be investigated and compared at AC, +DC and -DC. The two common polymeric materials for HVAC insulators, silicone rubber and ethylene propylene diene monomer, will be studied with various fillers and filler levels using the IPT at DC. Insulator design, for DC will be investigated in a salt-fog environment and existing designs for AC will be examined for use at DC at similar aging conditions. Modifications to insulator profile and material for optimum performance is expected to be the outcome of the research program.