人工盐雾环境下环氧树脂的绝缘特性

Insulation Performance of Epoxy Resin Under DC Electric Field and Artificial Saline Fog Environments

采用超声波盐雾发生器模拟沿海地区环境,在直流电场条件下测试了盐雾电导率对环氧树脂小绝缘间隙的绝缘特性的影响;借助单筒连续变倍视频显微镜观察实验前后试样表面状况,分析绝缘破坏过程。实验结果表明:盐雾液滴在环氧树脂表面的接触角随盐雾电导率的增大而减小;放电起始电压随盐雾电导率的增大而降低,随绝缘间隙的增大而升高;绝缘破坏电压随盐雾电导率的增大而降低,随绝缘间隙的增大而升高。

Epoxy resin is one of typical polymer materials and being widely used in the electric and electronic devices. With the miniaturization, high accumulation and environmental diversification of electrical devices, the epoxy resin is not only used in the normal environment but also in the contaminated conditions, especially in the saline-fog environment. Due to the effects of electric field and saline fogs, the chemical composition and physical morphology will change to accelerate the insulation failure, which reduces the lifetime of electrical devices, even causes the electrical accidents. In this paper, an ultrasonic vibration saline fog generator filled with saline solutions is employed to simulate the contaminated environment of littoral areas. The effects of saline fog conductance on the insulation performance of epoxy resin under a DC electric field are tested. The comparative observation reveals the changes of the sample surface before and after the test by using a monocular video-zoom-microscope. The study demonstrates that the contact angle of saline fog droplets on the sample surface decreases with increasing the conductance; the inception voltage decreases with increasing the conductance and increases with increasing the gap distance; the inception voltage decreases with increasing the conductance and increases with increasing the gap distance; the breakdown voltage decreases with increasing the conductance and increases with increasing the gap distance.