基于光纤传感器的输电杆塔角钢应变在线监测研究

Research on Online Monitoring of Angle Steel Strain of Transmission Tower Based on FBG Sensor

针对目前输电杆塔结构应力-应变监测方法中存在较大测量误差的问题,从提高输电杆塔角钢应变的测量精度出发,基于光纤光栅传感器提出一种考虑传感器在角钢表面安装位置及安装方式的输电杆塔角钢应变精准在线监测方法。首先,对输电杆塔角钢表面不同位置的应变分布特性进行有限元仿真分析;其次,根据输电杆塔结构中L角钢的形状特点,设计了一种可拆卸手环式的L型传感器固定夹具,对比分析了传感器不同安装方式对角钢应变测量精度的影响;最后,利用该方法设计了输电杆塔角钢应变在线监测系统。对某220 kV输电线路杆塔薄弱位置角钢进行应变数据实测分析,结果表明:实测数据和有限元仿真数据应变测量误差小于1.5×10^(-5),相对误差小于6.28%。研究结果为输电杆塔结构健康状态精准在线监测提供了参考依据,具有较高的工程实用价值。

Aiming at the problem of large measurement errors in the current stress-strain monitoring methods of transmission tower,this study was carried out to improve the accuracy of strain measurement of transmission pole and tower angle steel.Based on fiber bragg grating(FBG)sensor,an accurate online monitoring method for angle steel strain of transmission towers was proposed considering the position and mode of sensor installation on the surface of angle steel.Firstly,the transmission tower angle steel surface strain distribution characteristics of different positions were analized based on the finite element simulation,and then according to the transmission tower structure in L shape characteristics of angle steel,a removable hand ring type L-type joint angle sensor was designed on the surface of the fixed clamp.The comparison and analysis of different sensor installation methods and their influence on the angle steel strain measurement accuracy were examined.Finally,this method was used to design an accurate online monitoring system of transmission pole tower angle steel strain based on fiber bragg grating sensor.The strain data of angle steel in weak position of pole tower of a 220 kV transmission line was measured and analyzed.The results show that the strain measurement error of the measured data and the finite element simulation data was less than 1.5×10^(-5);and the relative error was less than 6.28%,which could effectively improve the measurement accuracy of the Angle steel strain of transmission tower.