A stabilization system for a rotating load, such as a flywheel, includes a mechanical bearing to continuously support a shaft of the rotating load so as to hold the shaft at a substantially fixed axis of rotation. A magnetic stabilization assembly includes a plurality of electromagnets arranged around the shaft. Control circuitry for controls a resultant magnetic field generated by the electromagnets such that the magnetic field acts on a ferromagnetic element of the shaft to reduce imbalance forces acting on the shaft.

A magnetic levitation control device comprises: a control signal generation section configured to generate a first excitation current control signal based on current deviation information on the excitation current detection signal with respect to the current setting signal and a second excitation current control signal based on the current setting signal; and a selection section including a first switching section configured to select either one of the first excitation current control signal or the second excitation current control signal or a second switching section configured to select either one of a third excitation current control signal obtained by summation of the first excitation current control signal and the second excitation current control signal or the second excitation current control signal. The excitation amplifier is PWM-controlled based on the excitation current control signal selected by the selection section.

An object of the present invention is to provide a magnetic bearing device designed to achieve reduction in cost and size of a circuit by omitting a DC/DC converter that has been used for obtaining a control power voltage of a magnetic bearing, and to provide a vacuum pump having the magnetic bearing device. The magnetic bearing device has: position detection means for detecting a radial position and an axial position of a rotor; magnetic bearing means for controlling the radial position and the axial position with an electromagnet based on the radial position and the axial position detected by the position detection means; an excitation circuit that includes a switching element for connecting/disconnecting between the electromagnet and a power supply; electromagnetic current detection means for detecting a signal of a current flowing through the electromagnet; power supply voltage detection means for detecting a signal of a voltage of the power supply; and pulse width calculation means for calculating, at each timing, a pulse width for operating pulse control for the switching element. The pulse width is calculated based on the voltage of the power supply detected by the power supply voltage detection means and the current detected by the electromagnetic current detection means.

An integrated journal bearing (IJB) includes a shaft extending in an axial direction, a housing through which the shaft extends in the axial direction, the housing surrounding the shaft in a radial direction, an active magnetic bearing (AMB) arranged within the housing and surrounding the shaft in the radial direction, and at least a first fluid film journal bearing (JB) arranged within the housing and surrounding the shaft in the radial direction. The first JB is axially adjacent to the AMB such that first JB and the AMB do not share a common radial clearance, while both are commonly flooded with oil. A controller in signal communication with the AMB can be variously configured to supply current thereto to operate the AMB by controlling a magnetic force generated thereby.

Provided is a magnetic bearing device which allows easy initial adjustment and allows optimal bearing control to be performed by a simple algorithm without increasing a memory capacity of a controller. A pair of square multipliers and an adder acquire respective steady-state current values of a pair of electromagnets which attract a rotor shaft of a magnetic bearing not shown in opposite radial directions, square the respective steady-state current values, and add up the respective squared steady-state current values. Then, to optimally change respective currents in the electromagnets in accordance with a mounting posture of the magnetic bearing, a correction coefficient arithmetic operator calculates a correction gain instruction value acting on the electromagnets from the steady-state current values squared/added up. Then, a gain instruction value obtained by adding the correction gain instruction value to a fundamental gain of a control circuit for the electromagnets is input to a gain amplifier. The gain amplifier generates a corrected current instruction value on the basis of the gain instruction value and optimally controls the magnetic bearing.

A magnetic bearing device includes a magnetic bearing including a plurality of electromagnets, a displacement sensor configured to output an output signal in accordance with a displacement of a shaft, and a controller configured to control the electromagnets. The controller compensates for a change in levels of the output signal, the change occurring in accordance with a change in ambient temperature around the displacement sensor, based on one or more reference values correlating with the change in levels of the output signal. The one or more reference values are detected for use in controlling the rotary electric machine, a fluid machine system including the rotary electric machine, or an apparatus including the fluid machine system.

A fluid module includes a fluid rotor configured to rotatably drive or be driven by fluid produced from a wellbore. A first shaft is coupled to the fluid rotor. The first shaft is configured to rotate in unison with the fluid rotor. A thrust bearing module includes a thrust bearing rotor. A second shaft is coupled to the thrust bearing rotor. The second shaft is configured to rotate in unison with the thrust bearing rotor. The second shaft is coupled to the first shaft. An electric machine module includes an electric machine rotor. A third shaft is coupled to the electric machine rotor. A third shaft is configured to rotate in unison with the electric machine rotor. The third shaft is coupled to the second shaft. The third shaft is rotodynamically isolated from the first shaft and the second shaft.

A device includes a rotor to rotate about a longitudinal axis, a magnetic bearing actuator, and an axial gap generator including a stator assembly adjacent to the rotor, the axial gap generator to generate an amount of power as a function of a gap spacing between the stator assembly and the rotor, the gap spacing parallel to the longitudinal axis, and the axial gap generator to supply the amount of power to a control coil of the magnetic bearing actuator.

A magnetic bearing control apparatus includes a plurality of output elements configured to generate electromagnetic force, a magnetic bearing configured to float a rotation shaft from a surface of the magnetic bearing based on the electromagnetic force generated by the plurality of output elements, at least one displacement sensor configured to sense a displacement of the rotation shaft, and a controller. The controller is configured to control a current supplied to the plurality of output elements, to control a position of the rotation shaft based on the current supplied to the plurality of output elements according to the displacement of the rotation shaft, and to determine a failure of the displacement sensor.

A shaft control method and device for a magnetic suspension system. The shaft control method for the magnetic suspension system includes: acquiring a displacement signal obtained by detecting displacement of a shaft in the magnetic suspension system (Step 101); separating whirling displacement from the displacement signal (Step 102); and controlling whirling of the shaft according to the whirling displacement (Step 103). By the disclosure, the effect of suppressing the whirling of the shaft during high-speed rotation of the magnetic suspension system is achieved.