荧光光纤温度传感器护套材料在变压器油中的热老化  

Thermal Aging of the Fluorescence Optical Fiber Temperature Sensor Sheath Materials in Transformer Oil

作　　者：高树国[1] 高骏[1] 潘瑾[1] 范辉[1] 王亚林[2] 尹毅[2] 

机构地区：[1]国网河北省电力公司电力科学研究院,石家庄050021 [2]上海交通大学电气工程系,上海200240

出　　处：《高电压技术》2017年第8期2599-2607,共9页High Voltage Engineering

基　　金：国家电网公司科技项目(5204HB15001S)~~

摘　　要：荧光光纤温度传感器长期浸没在变压器油中,随着使用时间的增加,其护套材料不可避免地会经历老化过程。通过有限元仿真发现荧光光纤温度传感器及其护套在工作时所处的电场很小,热老化是护套材料老化的主要形式。为此,针对荧光光纤温度传感器的3种不同护套材料即交联聚烯烃、聚氨酯和聚氯乙烯,在不同温度的变压器油中进行了热老化;然后使用Fourier变换红外光谱(Fourier transform infrared spectroscopy,FTIR)对试样的化学结构进行了辅助分析,并且基于机械拉伸实验和使用沿面电极布置形式的等温松弛电流方法,对不同护套材料的老化状态进行了分析评估。红外光谱实验结果表明:交联聚烯烃和聚氨酯护套在变压器油中热老化后均发生一定程度的分解,聚氯乙烯护套的红外光谱在老化前后没有大的变化。机械拉伸实验结果表明:交联聚烯烃护套的断裂伸长率和拉伸强度都大幅下降,聚氨酯护套的断裂伸长率下降但是拉伸强度却增加,而聚氯乙烯护套的断裂伸长率和拉伸强度均没有太大变化。等温松弛电流方法计算结果表明:老化后各种护套的老化因子值均大于未老化护套的值。综合评估可得:交联聚烯烃护套在油中热老化性能最差,聚氨酯护套次之,聚氯乙烯护套性能最好。With the increase of working time, a fluorescence optical fiber temperature sensor sheath will inevitably de- grade in power transformer. According to electrostatic simulation results, the sensor and its sheath normatly endures a quiet small electric force. Thus, thermal aging is the main factor influencing the insulation performance of the sheath dur- ing long working time. In this study, the fluorescence optical fiber temperature sensor sheaths made of three kinds of materials, such as cross-linked polyolefin, polyurethane and polyvinyl chloride, were subjected in hot transformer oil to degrade. The Fourier transform infrared spectroscopy （FTIR） experiments were used to explore the chemical structure of the sheaths. Moreover, the sheath insulation conditions were estimated based on the mechanical tensile test and the iso- thermal relaxation current test using a setup of surface electrodes. The FTIR results show that the cross-linked polyolefin and polyurethane sheaths may decompose after aging in transformer oil, whereas no obvious change of polyvinyl chloride sheath is observed. The tensile tests results manifest that the tensile strength and the elongation of cross-linked polyolefin sheath decrease dramatically. The elongation of polyurethane sheath decreases whereas the tensile strength increases with the increase of aging time. However, the elongation and the tensile strength of polyvinyl chloride sheath do not change much after aging. The isothermal relaxation current results demonstrate that the aging factor of aged sheath is larger than that of non-aged sheath. To sum up, the performances in hot transformer oil of different sheaths can be evaluated. The cross-linked polyolefin sheath is the worst, and the anti-aging characteristic of polyurethane sheath is better than cross-linked polyolefin sheath. The polyvinyl chloride sheath is the best.

关 键 词：等温松弛电流 荧光光纤温度传感器 护套材料 变压器 聚合物 热老化 状态评估 

分 类 号：TM41[电气工程—电器] TP212.11[自动化与计算机技术—检测技术与自动化装置]