磁势自平衡回馈补偿式直流传感器特性研究

在磁势自平衡回馈补偿式直流传感器中，检测补偿回路对系统的精度有很大影响。检测回路利用一对铁芯和线圈对一次被测电流和二次平衡电流磁势之差进行检测。根据铁芯近似矩形磁化曲线在分析其磁通变化的基础上，对检测回路进行了理论研究，给出了检测灵敏度的计算表达式。通过分析表达式，认为通过增大激励电压和总电流，提高取样电阻，增加铁芯材料相对磁导率、检测绕组匝数，增大铁芯截面积，减小平均等效磁路长度可以提高检测灵敏度，这些措施在实验中得到了验证，灵敏度最高达到了124mV／AT。根据磁势自平衡回馈补偿式直流传感机理，设计了实验样机，实验结果证明了这种新理论的正确性。

Theoretical Analysis of Characteristic for DC Sensor Based on Magnetic Potential Self-balance and Feed-back Compensation

The detection circuit has a major influence on the accuracy and sensitivity of DC sensor based on magnetic potential self-balance and feedback compensation.The difference of primary measured current and secondary balanced current is detected by the detection circuit with a pair of cores and coils.The theoretical research of the detection circuit is carried out based on the analysis of the detection cores' active states change,and the expression of detection sensitivity is given.In the expression,detection sensitivity can be improved by increasing power voltage,current and resistance,augment of cores specific magnetism,coils number and cores acreage,decreasing average equivalent magnetism way.These measures are proved in experiments,and the detection sensitivity reached to 124 mV/AT.Based on the magnetic potential self-balance and feed-back compensation,the testing of the prototype machine is made.Experiments confirm the validity of the new theory.