不同热老化程度的植物绝缘油太赫兹时域光谱特性研究

Research on Terahertz Time-domain Spectral Property of Vegetable Insulating Oil with Different Thermal Aging Degrees

植物绝缘油因其较好的绝缘性能及绿色环保等优势,逐渐成为传统矿物绝缘油替代品研究的热点。太赫兹波段光谱具有独一无二的指纹特征吸收峰,使其成为近年来物质检测热点技术之一。文中利用绝缘油的太赫兹时域光谱快速、准确、稳定的数据采集特性,对植物绝缘油的老化状态进行诊断。首先,利用改进的电磁波传递函数消除了仪器和容器的法布里—珀罗(F-P)效应。然后计算出植物绝缘油的吸收系数、折射率等THz谱参数,分析了植物绝缘油在太赫兹区域的介电性能。最后,与相应老化状态下的糠醛浓度进行对比,结果表明,糠醛浓度与平均折射率有相同的变化趋势。研究结果为THz-TDS技术在植物绝缘油老化状态评估领域的应用提供了很好的参考。

Vegetable insulating oil has gradually become a study hot spot in the replace of traditional mineral insulating oil due to its such advantages as better insulation performance and environmental protection. The terahertz band spectrum has a unique fingerprint characteristic absorption peak,making it one of the hottest technologies in substance detection in recent years. In this paper,the fast,accurate and stable data acquisition characteristics of the terahertz time domain spectrum of insulating oil is used to diagnose the aging state of plant insulating oil. First,the improved electromagnetic wave transfer function is adopted to eliminate the Fabry-Perot(F-P)effect of instruments and vessels. Then,the THz spectrum parameters such as the absorption coefficient and refractive index of the plant insulating oil are calculated and the dielectric properties of the plant insulating oil in the terahertz region are analyzed. Finally,it is compared with the furfural concentration in the corresponding aging state. The results show that the furfural concentration has the same variation trend as that of average refractive index. The research results provide a good reference for the application of THz-TDS technology in the field of plant insulating oil aging assessment.