磁悬浮转子的轴向位移常常利用电涡流传感器从转子轴向方向来检测,这一方法具有一定局限性。针对这一情况,在分析了电涡流传感器的工作原理以及输出特性的影响因素后,研究了利用被测导体的台阶表面来检测导体沿传感器径向方向的位移的方法。在该方法中,采用与差动相反的思想,将关于被测导体对称布置的两个传感器的输出进行加和,来消除传感器线圈与导体间距离的变化对检测结果的影响。结合磁悬浮转子的特性,提出了磁悬浮转子轴向位移径向检测的方法,并进行了实验验证,结果表明传感器的输出电压之和与转子轴向位移之间具有良好的线性关系和灵敏度,验证了该方法的正确性和可行性。
The axial displacement of maglev rotor is commonly detected by an eddy current sensor in the rotor axial direction;however this method is not suitable for some special applications.It is necessary to find a new method for detecting the axial displacement of maglev rotor.The operation principle and output characteristic influence factors of eddy current sensor are analyzed in this paper.A new method is proposed to detect the displacement of the tested conductor in sensor radial direction,which employs a step surface on the conductor.The output voltages of two sensors fixed symmetrically about the conductor are added together,which could eliminate the influence of the variation of the distance between the sensor coils and the conductor on the detection results.The new method was applied to detect the axial displacement of maglev rotor.Experiment results show that the sum of the two sensor output voltages has good linear relationship and high sensitivity with the rotor axial displacement,which proves the correctness and feasibility of the new method.