直流配电网隧道磁电阻传感器外磁场干扰模型及其抑制方法研究

隧道磁电阻传感器作为新一代磁传感器，具有温度特性好、灵敏度高等优点，在电能计量中得到大量研究和应用。外磁场干扰是影响磁传感器测量准确度的重要因素，文中针对直流配电网电流测量场景，建立了隧道磁电阻元件传感器阵列的外磁场干扰模型，继而基于自适应滤波(LMS)分析的算法，提出了磁传感器最优结构参数，并通过数值分析和有限元仿真验证了该模型的有效性。研究结果表明，当被测电流在±50 ~±300 A之间、阵列半径与母排间距比例为1:2.5时，外磁场影响最小，通过自适应滤波算法可将磁传感器测量误差降到1%以下。

Research on External Magnetic Field Interference Model and Suppression Method of Tunnel Magnetoresistive Sensor in DC Distribution Network

As a new generation of magnetic sensors, tunnel magnetoresistive sensors possess such advantages as good temperature characteristics, high sensitivity and so on, so it has been researched and widely applied in electric power measurement. External magnetic field interference is the key factor impacting the measurement accuracy of the magnetic sensor. In allusion to current measurement scenario of DC distribution network, firstly, an external magnetic field interference model of tunnel magnetoresistive element sensor array was established. Secondly, based on the algorithm of adaptive filtering analysis the optimal structural parameters of the magnetic sensor was proposed, and the effectiveness of the established model was verified by numerical analysis and Finite element simulation. Research results show that when the measured current is between ±50 A and ±300 A, and the ratio of the array radius to the busbar spacing is 1:2.5, the impact of external magnetic field is minimal. By means of adaptive filtering algorithm the measuring error of magnetic sensor can be reduced to less than 1%.