磁阀式电流互感器抗直流特性研究

磁阀式电流互感器(MVCT)气隙中的磁场传感器输出能够反映铁芯磁场强度与励磁电流的变化，因此在一定范围内能补偿畸变的二次电流，但已有研究缺乏理论分析与实验验证。在已有研究的基础上详细分析了MVCT的3种工作状态，推导了MVCT的等效磁化曲线与直流测量特性，使用温度特性好且灵敏度高的隧道磁阻(TMR)传感器进一步提高了补偿信号的补偿效果，并进行了直流电流、全波带直流偏磁、正弦半波电流与暂态电流的仿真与测量实验。仿真与实验结果表明，使用TMR传感器的MVCT同时具有测量直流电流、补偿电流互感器因直流偏磁电流而造成的稳态饱和与暂态饱和的能力。

Research on anti DC characteristics of magnetic-valve-type current transformer

The magnetic field sensor output in the incision of MVCT(Magnetic-Valve-type Current Transfor-mer) can reflect the variations of iron core magnetic field intensity and excitation current, and thus can compensate the distorted secondary current within limits. But the existing research is still lack of theoretical analysis and experimental verification. Based on the existing research, the three working states of MVCT are analyzed, and the equivalent magnetization curve and DC measurement characteristics of MVCT are deduced. The TMR(Tunnel MagnetoResistance) sensor with better temperature characteristics and higher sensitivity is used to improve the compensation effect of compensation signal. The simulations and measurement experiments of DC current, sinusoidal current with DC bias, half-sinusoidal current and transient current are carried out. The simulative and experimental results show that the MVCT using TMR sensor has the ability to measure DC current and compensate the steady saturation caused by DC bias current and transient saturation of current transformer.