Magnetic suspension bearing control method and device, magnetic suspension bearing, compressor

Abstract

The invention provides a magnetic bearing control method and device, a magnetic bearing and a compressor. The magnetic bearing control method comprises the steps of acquiring a first current Ia of a first coil and a second current Ib of a second coil; comparing |Ib-Ia| with a first preset threshold value M; and when |Ib-Ia| is greater than or equal to M, adjusting the currents in the first coil and the second coil to be a third current and a fourth current correspondingly so as to drive an axial thrust disk to generate first axial displacement towards one side of the coil with the current to be increased and to be stabilized in a dynamic suspended equilibrium position. According to the magnetic bearing control method and device, the magnetic bearing and the compressor provided by the invention, when axial external force is applied to a rotor shaft, the rotor shaft shifts towards one side of the coil with the current to be increased, so that stable suspension of the axial thrust disk onthe rotor shaft increases the magnitude of the control current, and the risk of rotor shaft unstable collision caused by excessive coil currents and bearing coil overcurrent saturation is reduced.

Description

technical field [0001] The invention belongs to the technical field of magnetic suspension bearing control, and in particular relates to a magnetic suspension bearing control method and device, a magnetic suspension bearing and a compressor. Background technique [0002] When the magnetic suspension bearing system is statically suspended, the axial direction of the rotor is only affected by the balanced electromagnetic force, and the axial thrust plate is suspended at the electromagnetic center position, which is the static suspension equilibrium position. The current of the front axial bearing coil is almost equal to the current of the rear axial bearing coil. When the magnetic levitation centrifugal compressor is running normally, the axial direction of the rotor will be subjected to increasing system pressure (the component force of the pressure generated by the internal compressed refrigerant in the axial direction of the rotor), and the system pressure will be superimpos...

AI Technical Summary

Problems solved by technology

When the axial shaft suddenly introduces an external force in the direction of the system force, the current of the bearing coil is too large and exceeds the controllable range of the bearing control, which will cause the risk of instability and collision of the shaft. At the same time, the current of the magnetic suspension bearing coil is too large. The current range becomes smaller, so this requires that the control current in the magnetic levitation bearing coil current should not be too large, so as to prevent the bearing instability that may be caused when the coil current reaches saturation.

Images