Abstract: A method for estimating the temperature of a stator coil of a magnetic suspension bearing of a rotor that is connected by connection wires to circuits for servo-controlling the position of the rotor includes the following steps: measuring the electric voltage at the terminals of the connection wires of the stator coil; measuring the intensity of the current passing through the stator coil; estimating the electric resistance of the stator coil and of the connection wires on the basis of an adaptive filter, the measured electric voltage and the intensity of the measured current; and estimating the temperature of the coil on the basis of the value of the estimated resistance.

Abstract: A lamination stack for use in a rotating electrical machine includes a plurality of sheets of ferritic material. Each of the sheets has first and second sides that include asperities, and the asperities have a height of about two microns and a width of about two microns. A layer of electrically insulating material is provided between adjacent pairs of the ferritic sheets in the stack, and the asperities extend into the electrically insulating material.

Abstract: The invention relates to a method of manufacturing a lamination stack used in a rotating electrical machine. The method includes providing naked sheets made of ferritic material; preparing both sides of each sheet so as to obtain a determined surface roughness; coating at least one side of each sheet with an chemically protective electrically insulating material; stacking the coated sheets; compressing the stack obtained; heating the compressed stack at a temperature above the melting temperature of the insulating material; and cooling down the compressed stack so as to form an integral lamination stack consisting of alternating sheets of ferritic material and layers of insulating material. The invention also relates to an electrical machine comprising such a lamination stack.

Abstract: A method of protecting ferromagnetic lamination stacks of a component of an electric machine, comprises the following steps: creating a component module by arranging a laminations stack of ferromagnetic sheets into a housing, (b) protecting locations of the component module where coating is unwanted, (c) inserting the component module into a hermetic chamber receiving an ionized gas, (d) polarizing the component module to submit a fixed electric potential to the component module, (e) depositing a thin layer of protective coating on the laminations stack of ferromagnetic sheets through a method of Plasma Enhanced Chemical Vapor Deposition (PECVD) at a temperature lower than 150° C., (f) monitoring the deposition homogeneity and deposition thickness of the thin layer of protective coating until desired thickness, and (g) rectifying the surface of the thin layer of protective coating to have a uniform protective layer.

Abstract: A landing bearing assembly for a rotary machine rotatable around a central axis and having a stator, a rotor with a shaft, a magnetic bearing, an auxiliary rolling bearing with two lateral faces, a landing sleeve facing, in normal operation of the rotary machine when the rotor is supported only by the magnetic bearing, the auxiliary rolling bearing at a nominal distance defined as the landing airgap El, the auxiliary rolling bearing coming into contact with the landing sleeve upon landing of the rotor in the event of a high shock. The assembly further provides a compliance ring with a nominal thickness Eo made from a material with a lower mechanical stiffness than the material constituting the other components of the landing bearing assembly to first absorb some energy of the shock by elastic deformation resulting in a reduction of its thickness.

Abstract: A stator assembly that provides a concentric housing and stator, the stator radially positioned inside the housing, the housing having an inner surface, the stator having an outer surface radially facing the inner surface. One of the outer surface of the stator and the inner surface of the housing has recessed shapes and the other one of the outer and inner surface has protruding shapes. When the two shapes are arranged in a first relative position, the protruding shapes are inserted in the recessed shapes so that the stator can be mounted radially inside the housing along a central axis of the assembly, and in a second relative position that is angularly shifted relative to the first position around the central axis, the protruding shapes exert, against the one of the housing and the stator that bears the recessed shapes, a radial force that angularly and axially locks the stator.

Abstract: The invention concerns an electrical installation providing an apparatus, a three-phase inverter and a control device, the inverter being adapted for generating a three-phase current presenting a first frequency for operating the apparatus and an undesired frequency component presenting a second frequency. The control device is adapted for measuring a parameter of each phase of the current, the measured parameters forming a measurement vector, and for calculating a Clarke transform, providing a first vector represented in a first basis of a two-dimensional vector space, of the measurement vector. The control device is adapted for generating a representation of the first vector in a second basis of the vector space, the second basis rotating at the second frequency with respect to the first basis.

Abstract: A device for detecting the axial position of a rotor shaft of a rotary machine having a stator and a rotor is provided. The detecting device includes a sensor stator ring, secured to the stator, made from ferromagnetic material, facing the shoulder of one end of the hollow or not hollow rotor shaft and arranged so as to leave an axial airgap with the one end of the rotor shaft. The sensor stator ring having at least one annular slot receiving an annular induction coil. The rotor shaft is made from solid magnetic steel, an outer end of the rotor shaft acts as a target surface whose axial position is to be measured by the sensor stator ring.

Abstract: A modular motor and magnetic bearing assembly comprising a positioning casing having a plane reference surface, an outer cylindrical reference surface, a central portion provided on an outer face with cooling liquid flow channels, and intermediate portions provided with openings for gaseous fluid entry and exit; a rotor presenting an inner cylindrical reference surface and a plane reference surface; an electric motor; radial magnetic bearings; an axial abutment; and auxiliary mechanical bearings. The modular assembly can then be incorporated in a main casing simply by sliding and it can be connected directly to a functional unit without reworking adjustments of the magnetic bearings.

Abstract: A magnetic bearing, adapted to equip a rotary apparatus. The magnetic bearing comprises: an actuator sub-assembly provided with a magnetic base and at least three actuator bobbins mounted on the magnetic base, and a sensor sub-assembly provided with at least three magnetic sensors associated with the actuator bobbins. At least one sub-assembly amidst the actuator sub-assembly and the sensor sub-assembly comprises at least three sectors mounted together. Each sector includes at least one actuator bobbin when the sector belongs to the actuator sub-assembly, or at least one magnetic sensor when the sector belongs to the sensor sub-assembly. The invention also concerns a rotary apparatus comprising such a magnetic bearing and a method for manufacturing such a magnetic bearing.

Abstract: A magnetic bearing, comprising: a magnetic base; at least three actuator bobbins mounted on the magnetic base; and magnetic sensors associated with the actuator bobbins. At least one magnetic system amidst the magnetic actuators and the magnetic sensors comprises together: a coil holder; a coil wound up around the coil holder; and a connector device integrated to the coil holder and designed for plugging at least one wire. Additionally disclosed is an apparatus comprising such a magnetic bearing and a method for manufacturing such a magnetic bearing.

Abstract: A method and system for determining core losses in a permanent magnet synchronous motor, comprising a measurement of the losses of the motor with the motor not connected to a load, and a deduction of the core losses of the motor from the losses of the motor. The motor is placed in an over-fluxing state during the measurement of the losses.

Abstract: An electronic magnetic bearing controller for controlling the position of a rotor of an electrical machine supported by an active magnetic bearing the position of which being measured by at least one inductive position sensor having an inductive coil, comprising an automatic reactive power compensation device for automatically compensating the reactive power consumed by the inductive position sensor.

Abstract: A hybrid magnetic suspension of a rotor (1) having compressor wheels (2, 3) having permanent magnets (104, 114) integral to shrunk fit rings (8, 18) arranged on the rotor (1) in the vicinity of the compressor wheels (2, 3), permanent magnets (124, 134) integral to stationary rings (23, 33) coaxially arranged with the rotor (1) and associated with a resilient material (5, 15) to define a passive radial magnetic bearing, coils (6, 16) associated with magnetic armatures (10, 20) and facing rotor parts (7, 17) being located perpendicularly to the rotor (1), and axial sensors (60, 160) configured for sensing the axial position of the rotor (1) and control means (200) configured for feeding the coils (6, 16) as a function of the outputs of the axial sensors (60, 160) for generating both axial bearing forces and a motor torque and thereby being adapted for defining an axial bearingless motor.

Abstract: A position detection device of active magnetic bearings (AMB's) maintaining the position of a rotating shaft and comprising two sensing inductance coils, the position detection device comprising a programmable digital component for generating a 25 KHz square waveform signal, a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and, depending on the displacement of the rotating shaft, an analog to digital (A/D) converter for delivering a position value from the voltage difference.

Abstract: A radial magnetic bearing having an inner rotor including a central shaft having a ferromagnetic armature mounted on the shaft and an outer stator providing a plurality of electromagnets including poles made of ferromagnetic material which project radially inwardly towards the rotor is provided. As such, air-gaps (e) are left between end faces of the poles and the ferromagnetic armature, and coils wound around the poles. The poles are extended through outer portions attached to a supporting member. Each pole and the corresponding outer portion are included in an angularly segmented module providing a stack of laminations made of ferromagnetic material. The outer portion defines shoulders with respect to the corresponding pole, the outer portion contacting outer portions of neighboring segmented modules and the outer portions of all segmented modules being assembled by clamping rings, wherein the coils located in free spaces around the poles are mounted in a string.

Abstract: A rotor sensor target for magnetic bearings, the rotor sensor target comprising a ring-shaped assembly of magnetic material mounted on a generally ring-shaped assembly of non-magnetic material. The magnetic and non-magnetic ring shaped assemblies are coaxially arranged and mounted on a shaft having a longitudinal axis of rotation X?-X. The generally ring-shaped assembly of non-magnetic material comprises at least one ring-shaped slit having the longitudinal axis X?-X and may be made of a cheaper material, such as aluminum. The ring-shaped slit provides flexibility which permits operation over a wide range of temperatures without risking of damaging the ring-shaped assembly of magnetic material.

Abstract: A permanent magnet rotor shaft assembly for a high speed electrical machine provides a permanent magnet cylindrical core having a longitudinal axis, the cylindrical core being axially compressed by first and second end shafts and being radially compressed by a sleeve made of a non-magnetic high strength metal. At least one of the first and second end shafts includes, facing the cylindrical core, a central shoulder head that cooperates with a mating central recess made in a central portion of a front face of the cylindrical core. An easy concentric alignment of the first and second end shafts with the permanent magnet cylindrical core is allowed while inserting the sleeve and the stiffness of the assembled set is enhanced.

Abstract: An electrical device comprising a housing having cooling fins located in a central portion along an exterior surface of the housing and a laminated magnetic stack disposed within the housing and interfacing with an interior surface of the housing at the central portion. The cooling fins are configured alternatively higher and smaller on an inlet manifold and in opposition on an outlet manifold.

Abstract: An assembly includes a rotating shaft supported with respect to a stationary housing by at least one active magnetic bearing presenting a mean radial air gap and at least one auxiliary bearing having first and second coaxially arranged annular surfaces is provided. One of the first and second coaxially arranged annular surfaces defines a clearance (E2) with one of the stationary housing and the rotating shaft, the clearance (E2) being less than the mean radial air gap and the other of the first and second coaxially arranged annular surfaces being integral with the other one of the stationary housing and the rotating shaft. The auxiliary bearing provides a first ball bearing and a second ball bearing having a misalignment with respect to each other in order to increase the starting torque.