隧穿磁阻(TMR)电流传感器失调与噪声消除技术  

Offset and Noise Elimination Technology for TMR Current Sensor

作　　者：刘卿[1] 张卫欣[1] 王崇 王季孟 侯昱丞 赵俊杰 杨挺 LIU Qing;ZHANG Weixin;WANG Chong;WANG Jimeng;HOU Yucheng;ZHAO Junjie;YANG Ting(State Grid Tianjin Electric Power Research Institute,Tianjin 300384,China;School of Electrical and Information Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]国网天津市电力公司电力科学研究院,天津市300384 [2]天津大学电气自动化与信息工程学院,天津市300072

出　　处：《电力建设》2019年第11期8-15,共8页Electric Power Construction

基　　金：国家电网公司总部科技项目“基于电磁诱导透明(EIT)和隧穿磁阻(TMR)效应的电磁测量技术研究”~~

摘　　要：采用隧穿磁阻(tunnel magnetoresistance,TMR)磁性元件的电流传感器具有精度高、体积小、功耗低等优点,在泛在电力物联网全面感知系统建立中具有很好的应用前景。TMR电流传感器的低频噪声与失调电压会对监测精度造成严重影响。针对该问题,文章分析了TMR电流传感器低频电路磁电阻薄膜1/f噪声、电路热噪声以及电路不匹配造成的失调噪声,提出了2种噪声消除方法:硬件电路斩波技术抑制噪声和基于自动调零原理的数值式自校正方法。通过实验实测,提出的方法能够抑制零点漂移电压,为高精度TMR电流传感器在泛在电力物联网中的应用提供技术支撑。The current sensors using TMR magnetic component, with the advantages of high precision, small size, and low power consumption, have good application prospects in the construction of ubiquitous power internet of things. In the practical application of TMR current detecting device, low frequency noise and offset voltage will cause quite serious effects. This paper analyzes the 1/f noise of the low-frequency circuit in the TMR current sensors, the thermal noise of the circuit and the offset noise caused by the circuit mismatch. Two noise elimination methods are proposed: the chopper circuit and the numerical self-calibration method based on automatic zeroing principle. In our experiment, the methods proposed can successfully suppress the drift voltage, providing technical support for the application of high-precision TMR current sensors in the ubiquitous power internet of things.

关 键 词：隧穿磁阻(TMR) 电流传感器 电路噪声 斩波 自校正 

分 类 号：TM933[电气工程—电力电子与电力传动]