A magnetic bearing control apparatus and a vacuum pump which do not require a displacement sensor, which enable control with high accuracy, and which are small and low cost. A rate of change (di/dt) that is a time derivative of a current value I.sub.m flowing through an electromagnet varies in accordance with a magnitude of a displacement of a gap between a target member and the electromagnet. The rate of change (di/dt) can be obtained by detecting a voltage value V.sub.s that is generated at both ends of an inductive element. Therefore, by detecting the voltage value V.sub.s, the magnitude of the displacement of the gap can be estimated by calculation. Inductive elements are connected in series to electromagnets and the voltage V.sub.s between the inductive elements is detected by the differential input amplifier. A single period of switching of a PWM switching amplifier is constituted by a current control period of the electromagnet and a displacement detection period for detecting the rate of change (di/dt). In addition, the displacement detection period is further constituted by a current increase period and a current decrease period which are certain periods of time. The current increase period and the current decrease period are equal to each other.

There is provided a controller for magnetic levitation equipment comprising a plurality of current source modules for connecting to at least one power supply for direct current, DC, and said current source modules comprising current channels for actuating coils of the magnetic levitation equipment, and a controller device connected to the current source modules by a control connection for controlling switching of electric current by the current source modules to the current channels. The current source modules combine discrete components for amplifying and switching electric current to the current channels into a single package. In this way, manufacturing and maintenance of the controller is facilitated, since manufacturing and maintenance may be based on the current source modules instead of discrete components, e.g. gate drivers, IGBTs, power mosfets and diodes.

The present disclosure provides a wiring structure of a magnetic suspension bearing, a compressor and an air conditioner. The wiring structure of a magnetic suspension bearing, for electrically connect a control coil of the magnetic suspension bearing with an external power source, includes a circuit board; wherein the number of the magnetic suspension bearing is two or more, and the control coils of the two or more magnetic suspension bearings are all configured to electrically connect to the circuit board, and the circuit board is configured to connect to the external power source. The present disclosure has the advantages of reasonable design, simple structure, implementation of integrating wiring of multiple magnetic suspension bearings, simplification of wiring work, improvement of production efficiency, and improvement of wiring reliability.

A downhole-type system includes a rotatable shaft; a sensor that can sense an axial position of the shaft and generate a first signal corresponding to the axial position of the shaft; a controller coupled to the sensor, in which the controller can receive the first signal generated by the sensor, determine an amount of axial force to apply to the shaft to maintain a target axial position of the shaft, and transmit a second signal corresponding to the determined amount of axial force; and multiple magnetic thrust bearings coupled to the shaft and the controller, in which each magnetic thrust bearing can receive the second signal from the controller and modify a load, corresponding to the second signal, on the shaft to maintain the target axial position of the shaft.

A magnetic bearing device for magnetically suspending a rotor (22) for rotation about a rotation axis (A) comprises an amplifier device, a first main coil (p) and a second main coil (n). In order to compensate for a stray flux that is created when the main coils are supplied with currents from the amplifier device, a compensation coil (c) is connected between a common node of the main coils and the amplifier device with such polarity that a current flowing through the compensation coil will diminish the stray flux caused by the main coils (p, n).

A compressor assembly is provided. Embodiments of the present disclosure generally relate to compressors used in chiller air conditioning systems for indoor spaces. The disclosed compressors have magnetic bearings that support rotating components. In one embodiment, the compressor comprises a partially segmented thrust bearing stator core. Additional systems, devices, and methods are also disclosed.

The present invention discloses a magnetic bearing of a stator permanent magnet motor with magnetic pole bypasses and a bias force adjusting method thereof, and belongs to the technical field of power generation, power transformation or power distribution. A typical magnetic field loop formed by permanent magnets extending out of stator sections, radial magnetic conduction bridges, circumferential magnetic conduction bridges, magnetic collecting shoes, radial/axial working air gaps and magnetic conduction blocks of radial/axial magnetic field closed main loops is used for designing the magnetic pole bypasses, so as to achieve the distribution of the magnetic field energy with multiple paths and controllable magnetic field strength of the permanent magnets in the stator permanent magnet motor. The present invention further provides a bias magnetic circuit structure. The number of magnetic poles and the magnetic field strength of a bias magnetic field are adjusted by selecting the materials of connecting sections between magnetic collecting blocks and the volume embedded in adjacent magnetic collecting blocks, so as to adjust the bias force of the magnetic pole, the space at an end of a motor winding is used to the greatest extent, the axial length of a magnetic suspension bearing motor system is reduced, the dynamic performance of a rotor is improved, and the objectives of high compactness and high integration level of “a magnetic suspension bearing and a permanent magnet motor system” are achieved.

Magnetic bearing control device and control method are disclosed. A magnetic bearing control device according to an embodiment of the present invention comprises: a bearing control unit for outputting a plurality of switch control signals on the basis of gap information of a bearing coil and a rotor and current information applied to the bearing coil; and a coil driving unit for turning a plurality of self-formed switching elements on/off in accordance with the plurality of switch control signals and controlling the amount of current applied to the bearing coil and thus adjusting the magnetic field strength between the bearing coil and the rotor. The bearing control unit generates and outputs the plurality of switch control signals such that bootstrap capacitor charging time of the coil driving unit may be secured. Therefore, a magnetic bearing control circuit structure may be simplified by means of an additional bootstrap capacitor structure.

A system for compensating for the stresses applied to a bearing that rotatably supports a rotor shaft of a rotating machine relative to a stator of the machine. The system provides at least one sensor for measuring an input signal positioned on an element of the bearing, a module for acquiring the input signal configured to convert the input signal into a value of the deformation applied to the rolling bearing, a module for determining a compensation signal as a function of the deformation value, and an amplifier module configured to control a magnetic actuator rotatably supporting the shaft of the rotor and including at least one electromagnet, the amplifier module being configured to convert the compensation signal into a voltage signal transmitted to the electromagnet of the magnetic actuator, the magnetic actuator being configured to exert a force on the rotor shaft as a function of the voltage signal.

An electrical drive includes an electrical machine, a first converter stage connected to terminals of stator phase-windings of the electrical machine, and a second converter stage connected to intermediate points of the stator phase-windings. A control device determines first component currents and second component currents so that torque is generated in accordance with electrical machine control and magnetic levitation force is directed to a rotor of the electrical machine in accordance with levitation control when portions of the phase-windings between the terminals and the intermediate points carry both the first and second component currents and the other portions of the phase-windings carry the first component currents. The reference currents for the first converter stage are determined based on the first and second component currents, and the reference currents for the second converter stage are determined based on the second component currents.