Capacitance Measuring Displacement Sensor Structure and It's Transducer for Radial Active Magnetic Bearing

摘要

A capacitance measuring displacement sensor structure for radial active magnetic bearing and a malfunction decision method thereof are provided to improve endurance against the noise delivered from the inverter or rotor by disconnecting the power ground in which a noise passes. A capacitance measuring displacement sensor structure for radial active magnetic bearing comprises a rotor providing virtual ground, cylindrical sensor electrode surfaces(110,111,112,113) arranged apart from the surface of the rotor, a guard electrode(120) covering the sensor electrode surfaces, a signal contact surface(130) surrounding the sensor electrode surfaces and the guard electrode surface and providing the reference of measurement signal, a stator body(300) placed outside the signal contact surface, a transducer(500) blocked from the sensor electrode, the guard electrode, and the signal ground of each sensor, a magnetic bearing controller(600) controlling a magnetic bearing, and a magnetic bearing driver(800) and an electric motor driving inverter(700) for the drive of the magnetic bearing.