基于光功率损耗的外绝缘表面污秽度检测系统影响因素研究

Study on influencing factors of external insulation surface contamination detection system based on optical power loss

为了提高基于光功率损耗的绝缘表面污秽度测量方法的精度,搭建了基于裸光纤的表面污秽度检测系统。基于该系统,对盐溶液浓度、灰悬浊液浓度、光纤形状、光源类型和光纤类型对表面附盐导致的光功率损耗的影响进行了实验研究,并对实验结果进行了较为深入的理论分析。实验结果表明:随着盐溶液浓度的增加,光功率损耗逐渐增大;灰悬浊溶液浓度对光功率损耗影响不大;采用U型光纤时的光功率衰减比直线型光纤更显著;采用宽谱(多纵模)光源时的光功率衰减比窄谱(单纵横)光源更显著;采用多模光纤的光功率衰减比单模更显著。理论分析结果很好地解释了以上实验结果,验证了实验结果的可靠性。进行基于光纤的外绝缘表面污秽度测量时应采用U型状态、半导体光源和多模光纤以提高测量精度。

In order to improve the accuracy of measuring method of insulation surface contamination degree based on optical power loss,a surface contamination degree measurement system based on bare fiber is established. Based on the established system,the influences of salt solution concentration,non-soluble salt solution suspension concentration,fiber shape,light source type and fiber type on the optical power loss caused by the salt deposit are experimentally investigated and the results are analyzed theoretically. The experimental results reveal that the optical power loss increases gradually along with the increase of salt solution concentration;the influence of the non-soluble salt solution suspension concentration on the optical power loss is not obvious;the optical power loss using U-shape optical fiber is more significant than that using linear shape optical fiber;the optical power loss using broadband(multi-longitudinal mode) light source is more significant than that using narrow spectrum light(single longitudinal mode)source;the optical power loss using multi-mode fiber is more significant than that using single mode fiber. The theoretical analysis results explain the experimental results well and verify the reliability of the experimental results. The semiconductor light source,multi-mode fiber and U-type state should be used in the contamination degree measurement based on the bare fiber in order to improve the measuring accuracy.