Abrégé

A linear actuator includes: at least one electromagnet arranged horizontally and magnet groups disposed at two sides of the electromagnet separately. Each electromagnet includes two magnetic poles, and the two magnetic poles are arranged at two ends of the electromagnet along an axial direction thereof. Each magnet group is opposite to the magnetic poles on sides of the electromagnet correspondingly, each magnet group includes at least two magnets, a side of a part of the magnets facing the electromagnet is S pole, and a side of another part of the magnets facing the electromagnet is N pole. After energizing the electromagnet, the magnet groups are driven to reciprocate along a direction perpendicular to a central axis of the electromagnet through magnetic induction action between the electromagnet and the magnet groups. A volume of the linear actuator can be reduced by the above structure.

Classes IPC  ?

• H02K 33/18 - Moteurs avec un aimant, un induit ou un système de bobines à mouvement alternatif, oscillant ou vibrant avec des systèmes de bobines se déplaçant, du fait de mises sous tension intermittentes ou inversées, par interaction avec un système de champ magnétique fixe, p. ex. des aimants permanents
• B26B 19/28 - Systèmes d'entraînement des tondeuses à cheveux ou des rasoirs à sec, p. ex. à commande électromotrice
• H02K 3/34 - Enroulements caractérisés par la configuration, la forme ou la réalisation de l'isolement entre conducteurs ou entre conducteur et noyau, p. ex. isolement d'encoches

Abrégé

A coil structure for an electromagnetic device comprising a conductor configured to provide a coil comprising one or more coil turns around a magnetic core to induce a magnetic flux in the magnetic core when in use. The conductor comprises one or more a first parts comprising a plurality of sub-conductors in parallel, and one or more second parts coupled in series with the first part(s), wherein the or each second part comprises a single sub-conductor or a lesser number of sub-conductors in parallel.

Classes IPC  ?

• H02K 3/26 - Enroulements caractérisés par la configuration, la forme ou le genre de construction du conducteur, p. ex. avec des conducteurs en barre constitués par des conducteurs imprimés
• B33Y 80/00 - Produits obtenus par fabrication additive
• H02K 3/28 - Schémas d'enroulements ou de connexions entre enroulements
• H02K 15/04 - Procédés ou appareils spécialement adaptés à la fabrication, l'assemblage, l'entretien ou la réparation des machines dynamo-électriques d'enroulements avant leur montage dans les machines
• H02K 15/0407 - Fabrication d’enroulements par gravure, impression ou emboutissage de bobines complètes

Abrégé

A control system for an electrical motor comprises a rotor, a stator having a plurality of phase windings, and an inverter for applying voltage to the plurality of phase windings by connecting individual phase windings to a first or second voltage level. The control system is configured to measure a first rate of change of current in a first phase winding, of said plurality of phase windings, connected to the first voltage level, to measure a second rate of change of current in a second, different phase winding connected to the first voltage level, and to calculate a difference between the first and second rate of change of current. The control system is further configured to use the calculated difference to obtain data related to a position of the rotor.

Classes IPC  ?

• H02P 6/18 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position
• H02P 6/182 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position utilisant la force contre-électromotrice dans les enroulements
• H02P 21/14 - Estimation ou adaptation des paramètres des machines, p. ex. flux, courant ou tension
• H02P 21/18 - Estimation de la position ou de la vitesse
• H02P 21/28 - Commande basée sur le flux statorique
• G01R 15/18 - Adaptations fournissant une isolation en tension ou en courant, p. ex. adaptations pour les réseaux à haute tension ou à courant fort utilisant des dispositifs inductifs, p. ex. des transformateurs

Abrégé

A control system for an electrical motor comprises a rotor, a stator having a plurality of phase windings, and an inverter for applying voltage to the plurality of phase windings by connecting individual phase windings to a first or second voltage level. The control system is configured to measure a first rate of change of current in a first phase winding, of said plurality of phase windings, connected to the first voltage level, to measure a second rate of change of current in a second, different phase winding connected to the first voltage level, and to calculate a difference between the first and second rate of change of current. The control system is further configured to use the calculated difference to obtain data related to a position of the rotor

Classes IPC  ?

• H02P 6/18 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position
• H02P 6/182 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position utilisant la force contre-électromotrice dans les enroulements
• H02P 21/00 - Dispositions ou procédés pour la commande de machines électriques par commande par vecteur, p. ex. par commande de l’orientation du champ
• H02P 21/14 - Estimation ou adaptation des paramètres des machines, p. ex. flux, courant ou tension
• H02P 21/24 - Commande par vecteur sans utilisation de détecteurs de position ou de vitesse du rotor
• H02P 25/03 - Moteurs synchrones avec excitation sans balai
• H02P 6/185 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position utilisant la détection par inductance, p. ex. excitation par impulsion

Abrégé

This supercharger has a magnetic flux switching motor that has: a rotor (26); a stator (24) that is an annular member that rotatably accommodates the rotor (26) and that has a plurality of stator protruding parts (60) that protrude radially inward from an internal circumference part (56A) toward the rotor (26); field parts (80) that are provided in field slots (62B) which are a portion of slots (62) among a plurality of the slots (62) formed between the stator protruding parts (60), the field parts (80) generating a magnetic field in a constant direction; armature coils (82) that are provided in armature slots (62A) which are the other slots (62) among the plurality of slots (62); and a control part that applies a single phase current to the armature coils (82), changes the direction of a magnetic field generated by the armature coils (82) by changing the direction of the applied signal phase current, and rotates the rotor (26). The supercharger also has a wheel that is attached to the rotor (26) and compresses a gas by rotating with the rotation of the rotor (26).

Classes IPC  ?

• H02K 3/52 - Fixation des enroulements de pôles saillants ou de leurs connexions
• H02K 11/30 - Association structurelle à des circuits de commande ou à des circuits d’entraînement

Abrégé

There is described a synchronous reluctance machine having a plurality of poles and comprising a stator with a plurality of spaced slots and a rotor. The rotor has one direct axis and one quadrature axis for each pole and comprises a plurality of flux barriers, each extending to a circumference thereof at least one barrier point. Successive angular separations between barrier points around the circumference of the rotor increase or decrease when moving around half a pole pitch from an initial axis to an adjacent finishing axis, the initial axis being one of a direct axis or a quadrature axis and the finishing axis being the other of a direct axis and a quadrature axis. The increase or decrease in size may be governed by a systematic progressive series.

Classes IPC  ?

• H02K 1/14 - Noyaux statoriques à pôles saillants
• H02K 1/24 - Noyaux rotoriques à pôles saillants
• H02K 21/16 - Moteurs synchrones à aimants permanentsGénératrices synchrones à aimants permanents avec des induits fixes et des aimants tournants avec des aimants tournant à l'intérieur des induits avec des noyaux d'induits annulaires à pôles saillants
• H02K 1/27 - Noyaux rotoriques à aimants permanents

Abrégé

There is described a synchronous reluctance machine having a plurality of poles and comprising a stator with a plurality of spaced slots and a rotor. The rotor has one direct axis and one quadrature axis for each pole and comprises a plurality of flux barriers, each extending to a circumference thereof at least one barrier point. Successive angular separations between barrier points around the circumference of the rotor increase or decrease when moving around half a pole pitch from an initial axis to an adjacent finishing axis, the initial axis being one of a direct axis or a quadrature axis and the finishing axis being the other of a direct axis and a quadrature axis. The increase or decrease in size may be governed by a systematic progressive series.

Classes IPC  ?

• H02K 1/24 - Noyaux rotoriques à pôles saillants

Abrégé

There is described a system for measuring an environmental parameter such as temperature experienced by a resistive component such as a thermistor (107) in a galvanically isolated circuit, or for measuring the voltage developed by a component. The system comprises a measurement circuit (1) comprising a voltage pulse generator (114). The measurement circuit is inductively coupled to the galvanically isolated circuit by a flyback transformer (101) such that a stable voltage (V104) across a first capacitor (114) in the measurement circuit after many voltage pulses is proportional to a stable voltage (V106) across a second capacitor (106) connected across the component in the galvanically isolated circuit. The stable voltages across the first and second capacitors are adjustable by adjusting a duty cycle of the voltage pulses.

Classes IPC  ?

• G01K 1/02 - Moyens d’indication ou d’enregistrement spécialement adaptés aux thermomètres

Abrégé

Disclosed herein is a design for flux switching machines with one or more armature windings which can deliver controlled torque, in either selected direction on start up, without the use of a mechanical position sensor. Flux switching machines without sensors can operate equally well in either direction. The invention discloses design features for such machines which improves the torque profile of the motor with angle. In three phase machines this delivers higher torque and lower ripple torque. In single phase flux switching machines the invention allows the rotor to be placed in a position where maximum torque can be delivered in either direction by selection of either positive or negative armature current. Rotor slotting is introduced to create a path of low permeability across a rotor tooth with minimal impact on the normal torque producing flux paths. Asymmetry of stator slots is used to further create a stable rotor position when energized by predominantly field means or armature means. Starting of the rotor from this stable position can be achieved in either direction. The method is suitable for starting permanent magnet flux switching motors. The invention results in low cost single phase motors which can start and run in either direction and three phase flux switching motors with improved performance over the prior art.

Classes IPC  ?

• H02K 1/22 - Parties tournantes du circuit magnétique
• H02P 25/08 - Moteurs à réluctance
• H02K 19/06 - Moteurs ayant un stator bobiné et un rotor en fer doux à réluctance variable, sans bobinage, p. ex. moteurs à fer tournant

Abrégé

A control system for an electrical machine drive system which actively controls the machine excitation during conditions of rapid acceleration or deceleration to bring the machine to rest at the point when a specified torque or force has been applied to a mechanical load. This is achieved without requiring any load torque transducer and automatically compensates for inertial energy in an active manner so that when the electrical machine comes to rest the load which has been applied is close to the specified value, irrespective of the rate of change of speed which has occurred. The system comprises an electrical machine, a mechanical drive mechanism connected between the output of the electrical machine and the load, a circuit to supply current to one or more of the windings of the electrical machine, the torque controller having a function of expected load torque variation with electrical machine speed and involving the steps of monitoring the electrical machine speed to calculate rate of change of speed; estimating inertial torque of the electrical machine system; estimating the electrical machine torque from measurements of currents and/or voltages; estimating load torque; calculating a load torque error between the estimated load torque and expected load torque obtained from the function of expected load torque variation evaluated at the instantaneous electrical machine speed and using the load torque error to increase or decrease the electrical machine torque.

Classes IPC  ?

• H02P 23/14 - Estimation ou adaptation des paramètres des moteurs, p. ex. constante de temps du rotor, flux, vitesse, courant ou tension
• B25B 23/00 - Parties constitutives ou accessoires des clés à écrous, clés anglaises, tournevis
• G05D 17/02 - Commande d'un coupleCommande de la puissance mécanique caractérisée par l'utilisation de moyens électriques

Abrégé

A control system for an electronically commutated motor (401) can rotate smoothly to very low speeds without using a high resolution encoder and can respond to variations in load without excessive speed fluctuations. The control system can be applied to motors operating with low resolution encoders and motors operating with sensorless rotor position feedback. The electronic control system can vary the magnitude and frequency of the stator excitation applied to one or more stator phase windings, the electronic control system comprising a frequency setting section (402) and a magnitude setting section (403) characterised by the fact that the frequency setting section (402) is constrained to operate over a limited range of frequencies, the maximum frequency being a function which is closely related to the frequency associated with rotation of the rotor at the desired speed.

Classes IPC  ?

• H02P 6/14 - Commutateurs électroniques

Abrégé

An observer (404), operating during a time when open loop control (402) is being used to drive a synchronous motor (401), the output of the observer (404) being a signal, E_I_angle, related to the angle between a rotational EMF vector and the current excitation vector, the observer (404) determining the angle by an iterative calculation incorporating a summation term, the summation term summing the variation of the quadrature component of a rotational EMF vector relative to an estimated EMF position vector, and using the angle output of the observer to update the estimate of the rotational EMF position vector. In a further aspect of the invention the observer output signal, E_I_angle, can be used to determine the transition to closed loop control (405), when the observer output signal reaches a value indicating conditions close to pull out conditions.

Classes IPC  ?

• H02P 23/03 - Dispositions ou procédés pour la commande de moteurs à courant alternatif caractérisés par un procédé de commande autre que la commande par vecteur spécialement adaptés pour les très faibles vitesses
• H02P 21/00 - Dispositions ou procédés pour la commande de machines électriques par commande par vecteur, p. ex. par commande de l’orientation du champ

Abrégé

Disclosed herein is a design for flux switching machines with one or more armature windings which can deliver controlled torque, in either selected direction on start up, without the use of a mechanical position sensor. Flux switching machines without sensors can operate equally well in either direction. The invention discloses design features for such machines which improves the torque profile of the motor with angle. In three phase machines this delivers higher torque and lower ripple torque. In single phase flux switching machines the invention allows the rotor to be placed in a position where maximum torque can be delivered in either direction by selection of either positive or negative armature current. Rotor slotting is introduced to create a path of low permeability across a rotor tooth with minimal impact on the normal torque producing flux paths. Asymmetry of stator slots is used to further create a stable rotor position when energised by predominantly field means or armature means. Starting of the rotor from this stable position can be achieved in either direction. The method is suitable for starting permanent magnet flux switching motors. The invention results in low cost single phase motors which can start and run in either direction and three phase flux switching motors with improved performance over the prior art.

Classes IPC  ?

• H02P 6/00 - Dispositions pour commander les moteurs synchrones ou les autres moteurs dynamo-électriques utilisant des commutateurs électroniques en fonction de la position du rotorCommutateurs électroniques à cet effet
• H02P 25/08 - Moteurs à réluctance
• H02K 19/06 - Moteurs ayant un stator bobiné et un rotor en fer doux à réluctance variable, sans bobinage, p. ex. moteurs à fer tournant

Abrégé

An inverter for the control of an electrical machine with p phase windings employs a control sequence for control of the inverter output voltage in which an inverter control block delivers a complete range of switching sequences determined by a single variable parameter, α, the variable parameter providing continuous variation of the fundamental component of the inverter output voltage from zero to a maximum value, the switching sequence for each inverter switching leg having an even integer number of switching transitions per electrical cycle, such that 2p points per electrical cycle exist where the state of the switching devices of the inverter are predetermined and independent of the single variable parameter, α.

Classes IPC  ?

• H02P 27/06 - Dispositions ou procédés pour la commande de moteurs à courant alternatif caractérisés par le type de tension d'alimentation utilisant une tension d’alimentation à fréquence variable, p. ex. tension d’alimentation d’onduleurs ou de convertisseurs utilisant des convertisseurs de courant continu en courant alternatif ou des onduleurs
• H02M 7/5387 - Transformation d'une puissance d'entrée en courant continu en une puissance de sortie en courant alternatif sans possibilité de réversibilité par convertisseurs statiques utilisant des tubes à décharge avec électrode de commande ou des dispositifs à semi-conducteurs avec électrode de commande utilisant des dispositifs du type triode ou transistor exigeant l'application continue d'un signal de commande utilisant uniquement des dispositifs à semi-conducteurs, p. ex. onduleurs à impulsions à un seul commutateur dans une configuration en pont

Abrégé

There is an increasing need for simple and low cost power supplies to control loads such as battery chargers and LEDs. It is the object of this invention to provide an alternative method for the control of current in such loads with very high efficiency and to reduce the variation of load current with supply voltage. This invention is particularly relevant to LED power supplies or battery chargers and provides an electronic power supply for the control of an electrical load connected to an electrical source, the electrical load comprising a main load with at least one LED and an auxiliary load with at least one LED, the electronic power supply comprising a series compensation block connected in series with the main load and the voltage source, the series compensation block providing a voltage in opposition to the voltage source by directly controlling the power delivered to the auxiliary load and indirectly controlling the power converted in the main load.

Classes IPC  ?

• H05B 33/08 - Circuits pour faire fonctionner des sources lumineuses électroluminescentes

Abrégé

The present invention relates to control of synchronous machines. A sensorless control system for an electrical machine is provided comprising a rotor and a stator having one or more phase windings for generating a rotating stator magnetic field. The current in the phase windings is monitored to determine real and imaginary components of the current vector in a rotating reference frame, from which real and imaginary components of the emf vector rotating in the rotating reference frame can also be determined. The ratio of the real and imaginary emf components is calculated, and an angular position of the rotational emf vector is estimated from this ratio. An angular error signal indicative of the deviation of the estimated angular position from a desired position in line with the real axis of the rotating reference frame is determined, and the machine is controlled such that the error signal tends towards zero.

Classes IPC  ?

• H02P 21/00 - Dispositions ou procédés pour la commande de machines électriques par commande par vecteur, p. ex. par commande de l’orientation du champ
• H02P 6/18 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position
• H02P 21/14 - Estimation ou adaptation des paramètres des machines, p. ex. flux, courant ou tension

Abrégé

A power supply circuit which offers a high efficiency and cost competitive solution to driving one or more low voltage LED strings from a higher voltage ac or dc supply. The power supply provides a dimming capability either by direct variation of the input supply or independently of the input supply by a simple internal controller. Aspects of the invention may be used without current feedback while obtaining acceptable current regulation, even under significant changes in the LED voltage or number of LEDs in a string. The power supply can drive one or more LED strings from a single power supply without the need to individually monitor the current in each string. A very low cost method to drive three colour LEDs and independently vary the current through each colour of LED to create a low cost colour blending power supply is provided. The power supply comprises at least two conversion stages, a first conversion stage comprising input terminals for connection to an ac or dc supply, an electronic converter with constant output current characteristics and output terminals for connection to at least one second conversion stages. Each second conversion stage comprises input terminals to receive a substantially constant current input from a first conversion stage, current multiplier circuit and output terminals for connection to a load. Circuits according to this invention are particularly suitable for lighting applications, for controlling the large number of LEDs in LED display panels or in backlighting for televisions and LCD displays.

Classes IPC  ?

• H05B 33/08 - Circuits pour faire fonctionner des sources lumineuses électroluminescentes

Abrégé

This invention relates to the control of electrical machines and is concerned more particularly, though not exclusively, with the control of flux switching brushless permanent magnet and switched reluctance electrical machines without a mechanical shaft position sensor. Brushless Reluctance and permanent magnet motors can be used in many applications, since they do not require the use of commutators or brushes in supplying electrical power to the rotor of the motor. An electrical machine is provided for converting electrical energy into mechanical energy and/or mechanical energy into electrical energy, the machine comprising a stator and a rotor, the stator having one or more electrical windings wherein at least one electrical parameter of the windings have a cyclic variation related to rotor position; at least one control device for controlling supply of electrical current to or from the or each said electrical winding, and at least one rotor position sensor means for detecting at least one electrical signal related to the cyclic variation of at least one electrical parameter of the or each said electrical winding wherein at least one said rotor position sensor means comprises the steps of measuring the said electrical signal at least once during any part of a switching cycle, conversion of the at least one measured electrical signal to a ratiometric quantity representative of an estimate of the rotor position corresponding to the at least one measured electrical signal and using the said ratiometric quantity in a calculation to maintain the current passing through the or each said electrical winding in synchronism with rotor rotation.

Classes IPC  ?

• H02P 6/18 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position
• H02K 29/06 - Moteurs ou génératrices à dispositifs de commutation non mécaniques, p. ex. tubes à décharge ou dispositifs à semi-conducteurs avec des dispositifs détecteurs de la position

Abrégé

The present invention relates to control of electrical machines and in particular, though not exclusively, to control of synchronous machines such as hybrid stepping motors, flux switching machines and brushless permanent magnet motors and generators. A sensorless control system for an electrical machine is provided comprising a rotor, a stator having one or more phase windings for generating a rotating stator magnetic field, the system comprising detection means for monitoring the currents in the phase windings providing a real component Is_real along a real axis at a known angle in line with a rotating reference frame and an imaginary component Is_imag orthogonal to the real component Is_real, calculating means for determining a value of the real component Es_real of the rotational emf along an axis at a known angle in line with a rotating reference frame and an imaginary component (Es_imag) orthogonal to the real component (Es_real), estimating means for estimating an angular position of the rotational emf vector using at least one of the estimated orthogonal components of the emf, error means for determining an angular error signal indicative of the deviation of the estimated angular position from a desired position, and synchronising means for controlling the machine such that the error signal tends towards zero.

Classes IPC  ?

• H02P 6/18 - Dispositions de circuits pour détecter la position sans éléments séparés pour détecter la position

Abrégé

The present invention relates to control of electrical motors and in particular, to the design and control of reluctance motors capable of micro-stepping position control. According to the invention there is provided a single stack variable reluctance machine with salient stator teeth and salient rotor teeth, the stator further comprising field magnet sections created by either permanent magnets or field windings or a combination of permanent magnets and field windings, and further comprising armature windings connected to form at least two armature phase windings, the armature phase windings connected to a power source or power electronic inverter for the supply of positive and negative current to at least two armature phase windings such that the rotor rotates in small incremental steps in response to small changes in the current in one or more of the phase windings.

Classes IPC  ?

• H02P 8/22 - Commande de la grandeur des pasÉchelonnement intermédiaire, p. ex. micro-échelonnement
• H02P 25/08 - Moteurs à réluctance
• H02K 37/04 - Moteurs à rotor tournant pas à pas et sans rupteur ou commutateur actionné par le rotor, p. ex. moteurs pas à pas du type à réluctance variable les rotors étant disposés à l'intérieur des stators

Abrégé

This invention relates to the control of electrical machines and is concerned more particularly, though not exclusively, with the control of flux switching brushless permanent magnet and switched reluctance electrical machines without a mechanical shaft position sensor. Brushless Reluctance and permanent magnet motors can be used in many applications, since they do not require the use of commutators or brushes in supplying electrical power to the rotor of the motor. An electrical machine is provided for converting electrical energy into mechanical energy and/or mechanical energy into electrical energy, the machine comprising a stator and a rotor, the stator having one or more electrical windings wherein at least one electrical parameter of the windings have a cyclic variation related to rotor position; at least one control device for controlling supply of electrical current to or from the or each said electrical winding, and at least one rotor position sensor means for detecting at least one electrical signal related to the cyclic variation of at least one electrical parameter of the or each said electrical winding wherein at least one said rotor position sensor means comprises the steps of measuring the said electrical signal at least once during any part of a switching cycle, conversion of the at least one measured electrical signal to a ratiometric quantity representative of an estimate of the rotor position corresponding to the at least one measured electrical signal and using the said ratiometric quantity in a calculation to maintain the current passing through the or each said electrical winding in synchronism with rotor rotation.

Classes IPC  ?

• H02P 6/10 - Dispositions pour commander l'ondulation du couple, p. ex. en assurant une ondulation réduite du couple
• H02P 25/08 - Moteurs à réluctance

Abrégé

This invention relates to the control of electrical machines and is concerned more particularly, though not exclusively, with the control of flux switching electrical machines without a mechanical shaft position sensor. An electrical machine for converting electrical energy into mechanical energy and/or mechanical energy into electrical energy, comprises a rotor having a plurality of rotor teeth; a stator having a plurality of stator teeth for rotatably receiving said rotor and having (i) at least one field magnet device for generating a first magnetomotive force between said rotor and said stator and including at least one first electrical winding, and (ii) at least one armature magnet device including at least one second electrical winding adapted to carry electrical current varying in synchronism with rotation of said rotor relative to said stator to generate a second magnetomotive force having a component transverse to said first magnetomotive force; at least one control device for controlling supply of electrical current to or from the or each said second electrical winding by applying a sequence of switching cycles wherein the electrical current in the br each said electrical winding has positive and negative conduction blocks, each of the said conduction blocks has at least two regions, including a first region and an end region; and at least one rotor position sensor device for detecting at least one electrical signal related to the rotational position of the rotor relative to the stator and induced in a respective said first or second electrical winding as a result of a current passing through a respective second or first electrical winding, wherein at least one said rotor position sensor device comprises the steps of measuring the said electrical signal during a switching cycle in the end region, and comparing the said measurement with at least one similar measurement in at least one previous switching cycle to determine if a known rotor position has been reached.

Classes IPC  ?

• H02P 6/10 - Dispositions pour commander l'ondulation du couple, p. ex. en assurant une ondulation réduite du couple
• H02P 25/08 - Moteurs à réluctance

Abrégé

An electrical machine comprising a rotor (11) with magnetic saliency but without windings, a stator (101) having stator teeth, the stator carrying armature windings (106, 111) wound with a pitch corresponding to a plurality of stator teeth and arranged around the stator to make one or more electrical phases, the stator also including a field magnet means, interspersed between every two stator teeth, wherein the field magnet means comprises at least one field winding (191, 192) and at least one permanent magnet (104, 105), and a field current control means such that variation of the direct current in the field windings changes the number of magnetic poles in the machine. The armature coils of the machine can be configured into one or more armature windings and circuits are described to excite the armature coils in the most efficient manner depending on the load or application requirements of the machine.

Classes IPC  ?

• H02K 21/04 - Bobinages disposés sur les aimants pour une excitation additionnelle
• H02K 19/10 - Moteurs synchrones pour courant polyphasé