基于振荡水滴法和放电特性的复合绝缘子老化研究

Aging of Composite Insulators Based on Oscillating Water Droplet and Discharge Characteristics

长期可靠性是输配电网高压绝缘子最重要的性能指标之一。一般情况下,通过研究绝缘材料的憎水性、表面粗糙度、扫描电镜图像和及其相关的放电特性以评估复合绝缘子的老化性能。据此,本研究提出了一种基于水滴振荡周期的复合绝缘子老化评价方法——振荡水滴法(Oscillating Water Droplet,OWD)。首先,通过在不同老化程度的绝缘试样上进行了OWD试验,利用高速摄影机记录并分析了水滴与复合材料表面接触的全过程。其次,利用光学接触角仪研究其憎水性,得到了表面振荡水滴与接触角的关系,并使用光学轮廓仪进行表面粗糙度测试。该试验结果表明,随着老化程度与粗糙度增加,绝缘材料的表面憎水性降低。最后,介质沿面击穿试验的结果表明,随着老化时间增加,绝缘材料的介质沿面击穿电压降低,绝缘可靠性变差。本研究提出OWD法可以作为一种评估复合绝缘子憎水性的补充方法。

Long-term reliability is one of the most important performance indicators for high-voltage insulators in power transmission and distribution networks.Typically,the aging performance of composite insulators is evaluated by studying the hydrophobicity,surface roughness,scanning electron microscope images,and related discharge characteristics of insulation materials.A novel aging evaluation method for composite insulators based on the oscillating water droplet(OWD) technique is proposed.Firstly,OWD tests were conducted on insulation samples at different aging stages,and the entire process of water droplet contact with the composite material surface was recorded and analyzed using a high-speed camera.Secondly,the relationship between the oscillating water droplet and the contact angle was investigated using an optical contact angle meter to study the hydrophobicity of the insulator.The loss of hydrophobicity was determined by conducting surface roughness tests using an optical profilometer.The experimental results demonstrated that with increased aging and surface roughness,the hydrophobicity of the insulation material decreased,leading to a significant decline in insulation performance.The breakdown test results indicated that the surface flashover voltage of the insulation material decreased with increasing aging time,resulting in deteriorated insulation reliability.In conclusion,the OWD method proposed in this paper can serve as a supplementary approach to assess the hydrophobicity of composite insulators and evaluate their long-term performance and stability.