非接触式直流输电差动GMI电流传感器及其传感特性研究

Research on non-contact differential GMI current sensor and its current-sensing characteristics for DC transmission lines monitoring

提出并表征了一种由铁基纳米晶带材FeCuNbSiB作为敏感元件的差动式巨磁阻抗效应GMI电流传感器,通过测试FeCuNbSiB带材在不同激励频率下巨磁阻抗变化率随外加磁场的变化关系,得出传感器工作频率以及最佳静态工作点。实验结果表明,非接触式差动GMI电流传感器的输出与所施加电流具有良好的线性关系,且灵敏度为0.46 V·A^(-1),与理论值0.5 V·A^(-1)吻合较好;线性度可达2.86%,比GMI电流传感器线性度提高了31.7%。本研究所提出的差动式GMI电流传感器具有非接触测量、高线性度、高灵敏度等突出优点,对直流输电线路在线监测具有潜在的应用价值。

A differential GMI current sensor consisting of iron-based nanocrystalline ribbon FeCuNbSiB as the key sensitive component was proposed and characterized.The variations of giant magneto-impedance ratio were measured with field sweeping under various driving frequencies,and then the working frequency and the optimum bias were obtained from the results.The experimental results demonstrate that the output of the presented sensor has a favorable linear relationship with the applied current,and the measured sensitivity of 0.46 V·A-1 matches well with the estimated value.The linearity of the sensor can reach the value of 2.86%approximately 31.7%higher than that of the one without differential.Therefore,these unique advantages of non-contact measurement,high linearity and high sensitivity exhibit great potentials for the GMI current sensor in the field of DC transmission lines monitoring.