物理科学与技术学院知识库

隧道磁电阻（TMR）作为一种高灵敏度，宽响应范围的磁阻技术，受到了世界范围磁学及磁性材料研究工作者的广泛关注。特别是其低激励电流，大变阻比，以及其线性输出的特征，非常适合电流传感应用。但到目前为止实验室所获得的TMR传感器的传感性能与理论差距很大，其主要原因是由于传感器的结构设计方面的原因所导致的。本文重点对TMR数字式电流传感器的结构设计进行了研究，通过对TMR组成数字式电流传感器的结构及电路系统优化，提高了电流测量的可靠性和准确性。根据国际标准规范IEC61036及国标GB/T17215中对电能计量设备的要求，通过实验对传感器系统的性能进行了测量研究。另外还研究了温度及外磁场对电流测试准确性的影响。结果表明，基于TMR的开环数字式电流传感器具有非常大的动态范围和精度，但是温度及外磁场对TMR数字式电流传感器仍有非常大的影响。

Tunneling magnetoresistance (TMR) was greatly focused by investigators in all the world due to its high sensitivity and wide frequency response range for MR technology. Specifically, TMR can be driven by very low power with wide resistance variation range also with good linearity. It can be ideally applied to current sensor application. However, the key parameters for the field sensing based on the TMR sensor in laboratory have quite large difference from the theoretic value due to the structure design. In this work, a TMR based digital current sensor was selected as the object for study. It shows a great improvement of the accuracy for the current measurement by optimizing the structure of the sensor and the electronic circuit design. The performance of the current sensor was verified in laboratory based on international standard IEC61036 and National standard GB/T17215 . Moreover, the influences of ambient temperature and magnetic field on the sensor performance were also investigated. The study showed that such a TMR based open-loop digital current sensor performs great dynamics and high linearity properties. However, the ambient temperature and magnetic field will still have a heavy influence on its properties.