基于声表面波的GIS开关触头温度监测的研究

发布时间：2019-05-22 06:57

【摘要】：在GIS开关触头温度监测领域应用方法中,无线测温存在电池维护的问题,且存在电池安全隐患；红外温度监测技术对GIS腔体改造大,部分区域光路被阻不能直接监测；光纤光栅温度监测技术布线困难,且存在闪络风险。与传统的温度监测技术相比,声表面波(Surface Acoustic Wave, SAW)温度监测技术具有绝缘性能好、抗电磁干扰能力强、无线信号传输、不需要现场电源等优点,可以广泛应用于GIS开关触头温度状态监测领域。本文首先对声表面波的测量原理进行了分析。研究了声表面波的芯片制造方法,使用YX-石英为压电材料的声表面波谐振器。探索了制作工艺对声表面波器件性能的影响,掌握了声表面波芯片的甄选方法,提高了器件的温度测量稳定性。研究了振动对声表面波温度传感器检测结果的影响,结果表明GIS内振动主要频段低于声表面波信号检测频段,振动不会对检测产生影响。开展了传输路径对声表面波温度传感器测量的影响研究,分析了声表面波信号频段在GIS内部不同结构中的衰减,提出了将读写器天线预埋入GIS腔体实现声表面波信号导入GIS的方法。根据GIS的特殊结构和绝缘要求,设计了高增益低损耗的环形声表面波温度传感器。该传感器安装在靠近触头的导杆上,直接测量该导杆温度,利用传热学模型仿真计算获得触头温度和导杆温度的定量关系,间接获得GIS触头部位的温度。设计了高性能读写器侧天线,该天线具有全向性、高增益、宽频带的优点,保证了安装在腔体内的传感器与腔体外的检测系统通讯,在不需要检测声表面波温度信号的时候,该天线还可以作为局放天线使用。设计了读写器模块,读写器采用混频的方式发射间歇正弦激励信号,对回波信号进行一次变频处理获得下变频信号。基于Lab VIEW设计了GIS触头温度监测系统软件,软件利用传感器标定结果将下变频信号转化为温度信息。通过有限积分法,研究了GIS内电磁波信号的传播特性,证实了声表面波温度监测系统的测量准确性。设计了读写器硬件滤波电路,提高了系统的抗干扰性能。为了检验所研制的传感器的工作性能,在实验室中对传感器进行了静态性能试验。试验结果显示：温度在0℃～100℃范围内变化时,声表面波温度传感器的非线性误差为0.98%,灵敏度为7.072kHz/℃,传感器迟滞误差为2.1%,传感器精度为2.49%,最高响应速度为1.7℃/s。为了检验实际工况中传感器的工作性能,对声表面波温度监测系统进行了温度试验。试验结果表明,在恶劣的电磁环境下,声表面波温度传感器工作正常,性能并未受电磁环境的影响而降低,通过声表面波传感器测量结果可以获得GIS开关触头的温度变化。
[Abstract]:In the field of GIS switch contact temperature monitoring, wireless temperature measurement has battery maintenance problems and hidden dangers of battery safety, infrared temperature monitoring technology has a large transformation of GIS cavity, some areas of optical path can not be directly monitored. Fiber grating temperature monitoring technology is difficult to route and flashover risk. Compared with the traditional temperature monitoring technology, saw (Surface Acoustic Wave, SAW) temperature monitoring technology has the advantages of good insulation performance, strong anti-electromagnetic interference ability, wireless signal transmission, no need for field power supply and so on. It can be widely used in the field of GIS switch contact temperature condition monitoring. In this paper, the measuring principle of surface acoustic wave is analyzed. The fabrication method of saw chip is studied. YX- quartz is used as piezoelectric saw resonator. The influence of fabrication process on the performance of saw devices is explored, the selection method of saw chips is mastered, and the stability of temperature measurement is improved. The effect of vibration on the detection results of saw temperature sensor is studied. the results show that the main frequency band of vibration in GIS is lower than that of saw signal, and the vibration has no effect on the detection. The influence of transmission path on the measurement of saw temperature sensor is studied, and the attenuation of saw signal band in different structures of GIS is analyzed. A method of introducing saw signal into GIS by embedding reader antenna into GIS cavity is proposed. According to the special structure and insulation requirements of GIS, a annular saw temperature sensor with high gain and low loss is designed. The sensor is installed on the guide rod near the contact, and the temperature of the guide rod is measured directly. The quantitative relationship between the contact temperature and the guide rod temperature is obtained by using the heat transfer model, and the temperature of the GIS contact is obtained indirectly. A high performance read and write side antenna is designed, which has the advantages of omnidirectivity, high gain and wide band, which ensures the communication between the sensor installed in the cavity and the detection system in vitro, when there is no need to detect the surface acoustic wave temperature signal. The antenna can also be used as a local antenna. The reader module is designed. The reader transmits the intermittent sinusoidal excitation signal by mixing, and carries on the one frequency conversion processing to the echo signal to obtain the down conversion signal. Based on Lab VIEW, the software of GIS contact temperature monitoring system is designed. The software converts the down conversion signal into temperature information by using the calibration results of the sensor. The propagation characteristics of electromagnetic wave signal in GIS are studied by finite integration method, and the measurement accuracy of saw temperature monitoring system is verified. The hardware filter circuit of the reader is designed to improve the anti-interference performance of the system. In order to test the working performance of the sensor, the static performance test of the sensor was carried out in the laboratory. The experimental results show that when the temperature varies from 0 鈩，

本文编号：2482763