我国电力工业发展蓬勃，拥有已达到世界领先水平的特高压输电工程。随着电压等级的进一步提高，对作为重要高压绝缘设备支柱绝缘子的设计、选型提出更高的要求，支柱绝缘子的更新换代迫在眉睫。灌注式支柱绝缘子是一种新型的支柱绝缘子，本文主要针对其聚氨酯芯体的孔泡特性、电气特性和吸湿特性，以及聚氨酯-环氧界面的绝缘特性和温度特性展开理论分析和试验方法的研究。探究了灌注式支柱绝缘子内部材料聚氨酯的孔泡特性，分析并总结出聚氨酯芯体中孔泡分布的规律，提出了一种基于压汞法的聚氨酯芯体孔泡评估方法。在孔泡特性探究的基础上，进一步研究聚氨酯孔泡特性与电气特性之间的关系。研究结果表明：灌注式支柱绝缘子聚氨酯芯体具有孔泡不均匀性，最内部孔泡和最外层孔泡分布较为致密，而两者之间的孔泡分布较为稀疏。灌注式支柱绝缘子聚氨酯芯体的孔泡不均匀性对于材料的局部放电量和击穿电压有很大的影响，具体表现为：孔泡越不均匀，其局部放量越大，击穿电压越小。研究了聚氨酯本体的吸湿特性、吸水特性以及水分在聚氨酯中的渗透特性。通过吸湿试验研究聚氨酯芯体吸湿和吸水时的质量变化，建立了水分在灌注式支柱绝缘子聚氨酯芯体中的渗透模型。设计并制作渗水试验模型，分别测量出液态水在聚氨酯中的渗透速度。试验结果说明：Langmuir模型较为符合水分在聚氨酯芯体中的渗透方式，聚氨酯反应物AB料比例会影响水分在聚氨酯芯体中的渗透方式，反应物B料比例越大其渗透模型越接近Fick模型。在聚氨酯渗水试验中分析得出水分在聚氨酯中是通过高分子网架结构进行渗透的，当反应物B料比例越大水分在聚氨酯芯体中渗透速率越快，且聚氨酯样品厚度与渗透速率成反比。最后，对灌注式支柱绝缘子聚氨酯-环氧界面特性展开研究，通过改进水渗透法和改进插针法对灌注式支柱绝缘子聚氨酯-环氧界面绝缘特性进行评估，并用力学方法对聚氨酯-环氧界面的温度特性进行评价。试验结果说明：聚氨酯反应物AB料比例会影响聚氨酯-环氧界面的绝缘特性，当聚氨酯反应物中A料的比例增加，界面绝缘特性好。并通过改进插针法分析得出聚氨酯-环氧界面的绝缘性能可以代表灌注式支柱绝缘子的整体内绝缘性能。低温环境会对聚氨酯-环氧界面的机械强度产生影响，经过温度循环后聚氨酯-环氧界面剪切力大大下降。
In recent years, China's power industry is booming and has UHV transmission projects that have reached the world's leading level. With the further improvement of the voltage level, higher requirements are placed on the design, selection and type of insulator insulators as important high-voltage insulation devices. The replacement of post insulators is imminent. Perfusion-type post insulator A new type of post insulator. This paper focuses on the bubble characteristics, electrical properties and hygroscopic properties of the polyurethane core, as well as the mechanism analysis and test methods for the insulation properties and temperature characteristics of the polyurethane-epoxy interface.The pore characteristics of polyurethane in the inner material of the cast-in-pillar insulator were investigated. The distribution of pores in the polyurethane core was analyzed and summarized. A new method for evaluating the pores of polyurethane core was proposed. Based on the investigation of the characteristics of the pores, the relationship between the properties of the polyurethane pores and the electrical properties was further studied. The results show that the perfusion-type post insulator polyurethane core has pore non-uniformity, and the innermost pores and the outermost pores are densely distributed, and the pores between the two are sparsely distributed, and the pores are not The uniform partial discharge and the breakdown voltage of the material have a great influence. The more uneven the pores, the larger the partial discharge and the smaller the breakdown voltage.The hygroscopic properties, water absorption properties of polyurethane bodies and the permeability characteristics of moisture in polyurethanes were investigated. The moisture absorption test was used to study the mass change of the polyurethane core during moisture absorption and water absorption, and the penetration model of moisture in the polyurethane of the perfusion pillar insulator filler was established. The water seepage test model was designed and fabricated to measure the penetration rate of liquid water in the polyurethane. The test results show that the Langmuir model is more in line with the permeability of water in the polyurethane core, but the larger the proportion of the reactant B material that produces polyurethane, the closer the permeability model is to the Fick model, and the better the water absorption performance of the resulting polyurethane. In the polyurethane water permeability test, it is analyzed that the moisture penetrates through the polymer grid structure in the polyurethane. When the ratio of the reactant B material which generates the polyurethane is larger, the penetration rate of the moisture in the polyurethane core is faster, and the thickness of the polyurethane sample is The rate of penetration is inversely proportional.Finally, the polyurethane-epoxy interface characteristics of the perfusion post insulator were studied. The polyurethane-epoxy interface insulation properties of the perfusion post insulator were evaluated by the improved water penetration method and the improved pin method. The perfusion type post insulator polyurethane-epoxy was studied. The temperature characteristics of the interface. The ratio of the polyurethane reactant AB material will affect the insulation properties of the polyurethane-epoxy interface: when the proportion of the A material in the polyurethane reactant increases, the leakage current at the interface portion is small, and the interface insulation property is good. The relationship between the interface insulation performance and the overall insulation performance was preliminarily discussed. The pressure test was carried out on the perfusion-type post insulator model filled with different components of polyurethane by the improved pin method. It was verified that the polyurethane-epoxy interface can represent the perfusion type. The overall internal insulation properties of the post insulators. The temperature characteristics of the polyurethane-epoxy interface were studied, and the influence of temperature stress on the mechanical strength of the interface was investigated.
