Wide-Range Displacement Sensor for Vibration Measurement of Magnetically Suspended Air-Blower

The displacement measurement is critical to the stable suspension and position control of magnetically suspended air-blower, and the eddy current sensor is a typical sensor to measure the dynamic displacements between the rotor shaft and the stator part. The displacement coordinate of magnetically suspended air-blower on multi degrees of freedom is firstly developed, and then the detection principle of eddy current displacement sensor is researched. Furthermore, the design processes of displacement sensor including dimensional parameters and quality factor are presented, and then the simulation had been conducted. Finally, the measurement experiments of magnetically suspended air-blower using the displacement sensor system are conducted, the results indicate that the linear range of displacement measurement approaches to 7.5 mm, the relative error is smaller than 2%, and the temperature stability is 0.022%/°C. Therefore, the displacement measurement and vibration analysis of magnetically suspended air-blower could be realized by the designed displacement sensor system.