随着直流输电线路逐渐广泛应用,直流电流准确测量的需求日益迫切。文中提出一种新的基于巨磁电阻效应的直流电流测量方法,研究了巨磁电阻传感器静态磁场下的外特性及温度变化对巨磁电阻传感器性能的影响,在此基础上设计了直流电子式电流互感器的整体结构。分析了实际应用中巨磁电阻传感器所表现出的非线性,提出了相应的非线性补偿方法。实际测试结果验证了该方法的有效性。
With the wide application of DC transmission line in the power system, the requirement on the accurate measurement of DC current is urgent. A novel DC current measurement method based on the giant magneto-resistance is presented. The static input-output characteristic of giant magneto-resistance sensor, and the influence of temperature are studied. On that basis, the overall structure of DC electronic current transformer is designed. The non-linear characteristic of the giant magnetoresistance sensor is analysed, and a non-linear compensation method proposed. Measurement results verify the proposed method.