磁轴承用位移传感器差动安装的误差补偿方法研究

Research on the error compensation method for differential installation of displacement sensor for magnetic bearing

差动测量方法由于具有测量灵敏度高、能减小传感器温漂误差、降低共模信号干扰、消除传感器偏置耦合等特点而广泛应用于位移测量。磁轴承采用差动方式测量转子位移时,虽然具有差动测量的优点,但也引入了因位移特性的不一致性而产生的动态差动误差、及因传感器差动安装位置的不同而导致差分信号与转子实际位移间产生的不同偏差等问题。针对以上问题,提出了一种磁轴承用位移传感器差动安装的误差补偿方法,采用投影补偿法补偿差分信号中的位移特性不一致误差,推导了差动测量下转子的位移方程,并通过位移方程求解出磁轴承转子的实时位移。仿真及实验表明采用位移传感器差动安装的误差补偿方法,转子位移的差动测量误差从2.5%提高到了0.16%,对于提高磁轴承控制精度及稳定性具有重要的意义。

The differential measurement method has advantages of high sensitivity,low drift error of sensor temperature,low common mode signal interference and elimination of sensor bias coupling.Therefore,it is widely used in the displacement measurement of the rotor of the magnetic suspension bearing.When the magnetic bearing utilizes the differential method to measure the rotor displacement,it also introduces the dynamic differential error caused by the inconsistency of the displacement characteristics.In addition,the deviations between differential signal and actual rotor displacement are caused by the difference of sensor differential installation position.To solve these problems,a method of error compensation for differential installation of displacement sensor for magnetic bearing is proposed.The projection compensation method is utilized to compensate the inconsistency error of displacement characteristics in differential signals.The displacement equation of the rotor under differential measurement is derived,and the real-time displacement of the rotor of magnetic bearing is solved through the displacement equation.Simulation and experimental results show that the differential measurement error of rotor displacement is decreased from 2.5%to 0.16%by using the error compensation method of differential installation of displacement sensor.It is of great significance for improving the control precision and stability of magnetic bearing.