基于超声探测的SF_6浓度在线监测系统  

On- line Monitoring System of SF_6 Concentration Based on Ultrasonic Detection

作　　者：邓扬[1] 王先培[1] 陈鹏[1] 肖伟[1] 胡明宇[1] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430072

出　　处：《仪表技术与传感器》2015年第10期71-74,共4页Instrument Technique and Sensor

基　　金：国家自然科学基金资助项目(50677047);中国南方电网公司科技项目(K-GX2011-019)

摘　　要：长期运行的气体绝缘组合电器(GIS)设备可能存在SF6气体泄漏问题,进而导致设备安全性下降。针对该问题,采用超声原理测量SF6气体浓度,该方法具有测量范围广、设计简单等优点,且易于实现在线式监测。建立了双腔室中超声信号传播相位差与SF6气体浓度的理论模型,并研制了一套基于超声探测的SF6浓度在线监测系统。为提高测量精度,设计了一种基于DFT算法的数字相位计,通过对采样信号进行多项式插值加Hanning窗,进而实现相位和幅值修正。实验表明,使用数字相位计能将SF6浓度误差率控制在5%左右,目前该系统在贵州某变电站已投入运行。SF6 gas leakage can exist in long- term operation of Gas Insulated Switchgear（ GIS） equipment,which led to the reduction of device security. In terms of this problem,ultrasonic technique was used in the SF6 gas concentration detection. This method has the advantages of wide measuring range and simple design. Besides it is feasible to monitor on- line. A theoretical model of ultrasonic signal propagation phase difference in the dual chamber with the SF6 gas concentration was established,and an on- line monitoring system of SF6 concentration based on ultrasonic detection was developed. To improve the measurement accuracy,a digital phase meter was designed based on the DFT algorithm,with polynomial interpolation and Hanning window algorithm used to the sampling signal,the phase and amplitude can be corrected. Experiments show that the SF6 concentration error rate can be controlled at about 5% with this digital phase meter,currently the system has been put into operation in one of transformer substations in Guizhou.

关 键 词：超声 SF6浓度监测 相位差 数字相位计 多项式插值 HANNING窗 

分 类 号：TB55[理学—物理]