Abstract: A multiphase motor comprises a plurality of ferromagnetic stator core segments, the core segments being substantially uniformly spaced around an axis of rotation and isolated from direct contact with each other. Each core segment forms at least one pair of poles having coils wound thereon to form a phase winding. Each stator phase winding is configured with a topology different from the topology of each of the other phase windings. Each phase winding has a different total number of coils from one or more of the other phase windings. Each phase winding comprises coils of a gauge different from the coil gauge of one or more of the other phase windings. Preferably, all of the phase windings have substantially the same total coil mass.

Abstract: A permanent magnet motor has rotor structure that includes magnetically permeable backing material attached to magnets for enhancing flux density distribution. A plurality of permanent magnets are circumferentially distributed about an axis of rotation, adjacent magnets successively alternating in magnetic polarity. The magnetically permeable material is configured with apertures therethrough at areas of low flux density, such as at central portions of the magnets, while in contact with perimeter areas of the magnets. Additional apertures in the material may be located at spaced intersections at which no significant flux density exists. The apertures may be replaced with backing material portions of reduced radial thickness.

Abstract: A multiphase motor has a plurality of ferromagnetically isolated stator electromagnets distributed about an axis of rotation. Successive ranges of speed during which the motor can be expected to operate are defined. A specific subset of the electromagnets is associated for each speed range, each specific subset comprising a different combination of electromagnets. Respective voltage magnitudes to be applied to each phase winding for each defined speed range are predefined. The motor speed is sensed throughout motor operation. In each defined speed range, only the electromagnets of the associated subset are energized, each of the energized electromagnets having applied thereto a different predefined voltage magnitude.

Abstract: Rotary permanent magnet motors have salient stator poles with nonuniform pole thickness in the radial direction for compensating effects of cogging torque. Pole base portions terminate at pole shoes at the radial air gap. The pole shoes extend in the circumferential direction from the bulkier base portions. Variation of the thickness of the pole shoe changes the concentration of the effective flux at the point of coupling between the stator poles and the permanent magnet pole shoes. As there is no change in the active interfacing area of the pole shoes a uniform air gap is maintained. The torque signature for each stator pole/rotor permanent magnet interface can be selectively changed to smooth motor operation by configuring the stator pole shoe thickness to vary along its circumferential extent as appropriate. Pole shoes may have tapered leading or trailing edges with respect to a pole base to change the effective flux density in the air gap at a specific pitch of rotation.

Abstract: A novel cruise control system is provided for adaptively controlling an electric vehicle to maintain desired speed under variable driving conditions. This system utilizes multiple motor control scheme for controlling the motor using various waveform profiles of the control current, and involves phase advance angle adjustment provided for adaptively controlling a phase advance angle between the control current and back-EMF in response to changes in driving conditions to produce the control current sufficient to achieve the desired speed. A motor control scheme selection circuit enables the cruise control system to select a current waveform profile appropriate for present driving conditions. A selected current waveform profile is modified, if the control current with the adjusted phase advance angle is not sufficient to achieve the desired speed.

Abstract: A permanent magnet motor includes salient pole stator cores. The poles and/or linking portions therebetween are wound with a plurality of winding coil sets. Mutually exclusive speed ranges are established between startup and a maximum speed at which the motor can be expected to operate. A different number of the motor stator winding coils are designated to be energized for each speed range for maximum operating efficiency. The number of energized coils are changed dynamically as the speed crosses a threshold between adjacent speed ranges.

Abstract: An electrically powered vehicle has a motor, controller and power supply contained within a wheel compartment. A cylindrical stator frame is fixed on the wheel axle, with an inner surface of the stator frame defining a space for housing the power supply and controller circuitry. A plurality of electromagnet stator segments are mounted on an outer surface of the stator frame. A cylindrical rotor frame is coupled to the axle through bearings. An inner surface of the rotor frame supports a plurality of permanent magnets that surround the stator segments to form a radial air gap therebetween. Mounted to the outer surface of the rotor frame by appropriate supporting structure is a vehicle tire.

Abstract: Reconfiguration of stator winding sections of each phase of a multiphase motor is controlled for successive ranges of speed during which the motor can be expected to operate to obtain optimum operating efficiency throughout the entire operating range. All winding sections for a stator element are energized throughout the motor operating speed range but connected, through appropriate switches, in different circuit configurations for respective portions of the speed range. The switches are activated by a controller in response to a sensed motor speed signal. The reconfiguration of stator winding sections may be incorporated within a motor control system that is adaptive to control various motor parameters in response to sensed conditions as well as user input commands.

Abstract: A control system is provided for a multiphase motor having a plurality of stator phase components, each stator phase component comprising a phase winding formed on a core element, and a permanent magnet rotor. A plurality of motor control schemes are stored in memory. Subject to user or system selection, one of the motor control schemes is accessed from the memory by a controller for implementation. The controller generates control signals that are applied to energization circuitry for supplying current to the phase windings with a particular current waveform profile in accordance with the selected motor control scheme. The controller has an input terminal for receiving a user initiated torque command signal representing a desired motor torque. Each motor control scheme provides motor driving current that corresponds to torque command signals received at the controller input terminal.

Abstract: A novel system for adaptively controlling an electric vehicle to maintain desired speed under variable driving conditions. The system includes a control circuit for producing a control signal to control an electric motor of the vehicle. The control signal is formed based on a control current required to achieve the desired speed. The control strategy selection circuit is configured in the system to determine a motor control scheme that provides an appropriate waveform profile of the control current.

Abstract: A multiphase brushless permanent magnet motor has a stator provided with at least one winding for each phase, the windings permanently connected to each other at a plurality of junctions. A power source is coupled, via controlled motor energization circuitry, to a plurality of terminals connected to respective junctions, the number of which terminals is fewer than the number of motor phases. The motor energization circuitry is appropriately controlled by a central processor. A reduced number of controllable states is achieved while retaining a high degree of precision controllability. Thus, duplication of identical energization circuitry for each phase is avoided.

Abstract: A motor has a rotor and a stator. The stator is made up of a plurality of separate electromagnet core segments disposed coaxially about an axis of rotation. The core segments are affixed, without ferromagnetic contact with each other, to a non-ferromagnetic support structure. The rotor is configured in an annular ring that at least partially surrounds the annular stator to define two parallel axial air gaps between the rotor and stator respectively on opposite axial sides of the stator. Permanent magnets are distributed on each side of the rotor annular ring that faces an air gap. Preferably, each stator electromagnet core segment has a pair of poles aligned in a direction generally parallel to the axis of rotation with pole faces generally perpendicular to the axis of rotation. A winding is formed on a core portion that links the poles to produce, when energized, magnetic poles of opposite polarity at the pole faces.

Abstract: A rotary electric motor is formed within a cylindrical rotor housing structure that surrounds an annular stator ring. The permanent magnet rotor is configured in an annular ring coaxial with, and outside of, the stator. The stator ring contains a plurality of wound core segments that are ferromagnetically isolated from each other. The core segments are secured to a rigid skeletal structure that is centrally fixed to a stationary shaft. The stator support structure is formed of spine members that extend radially away from the center. U-shaped plates at the outer ends of the spine members engage adjacent pair of stator segments. Within the inner periphery of the stator ring, space is provided within which motor control circuitry and battery power supply may be incorporated.

Abstract: A dynamoelectric generator comprises a rotor having a plurality of permanent magnet elements disposed in an annular ring configuration about an axis of rotation, the magnet elements successively alternating in magnetic polarity along an inner annular surface, and a stator spaced from the rotor by a radial air gap. The stator includes a plurality of magnetic core segments having respective coils wound thereon to form stator windings, the core segments separated from direct contact with each other and disposed along the radial air gap. Each stator segment comprises a plurality of poles aligned with each other in a direction parallel to the axis of rotation. Thus the stator comprises a plurality of sets of stator poles in radial alignment, the sets being axially displaced from each other.

Abstract: A multiphase motor comprises a plurality of ferromagnetic stator core segments, the core segments being substantially uniformly spaced around an axis of rotation and isolated from direct contact with each other. Each core segment forms at least one pair of poles having coils wound thereon to form a phase winding. Each stator phase winding is configured with a topology different from the topology of each of the other phase windings. Each phase winding has a different total number of coils from one or more of the other phase windings. Each phase winding comprises coils of a gauge different from the coil gauge of one or more of the other phase windings. Preferably, all of the phase windings have substantially the same total coil mass.

Abstract: A cascaded motor arrangement is configured with a plurality of rotor/stator sets that extend in an axial direction. A stator set contains a plurality of separate electromagnet core segments disposed coaxially about an axis of rotation. The core segments may be affixed, without ferromagnetic contact with each other, to a non-ferromagnetic support structure. A rotor set is configured in a U-shaped annular ring that at least partially surrounds the annular stator set and may define two parallel axial air gaps between the rotor and stator respectively on opposite axial sides of the stator and at least one radial air gap. Permanent magnets are distributed on each inner surface of the U-shaped rotor annular ring that faces an air gap. A winding is formed on a core portion that links axially aligned stator poles to produce, when energized, magnetic poles of opposite polarity at the pole faces.

Abstract: A permanent magnet motor has rotor structure that includes magnetically permeable backing material attached to magnets for enhancing flux density distribution. A plurality of permanent magnets are circumferentially distributed about an axis of rotation, adjacent magnets successively alternating in magnetic polarity. The magnetically permeable material is configured with apertures therethrough at areas of low flux density, such as at central portions of the magnets, while in contact with perimeter areas of the magnets. Additional apertures in the material may be located at spaced intersections at which no significant flux density exists. The apertures may be replaced with backing material portions of reduced radial thickness.

Abstract: A permanent magnet motor includes salient pole stator cores. The poles and/or linking portions therebetween are wound with a plurality of winding coil sets. Mutually exclusive speed ranges are established between startup and a maximum speed at which the motor can be expected to operate. A different number of the motor stator winding coils are designated to be energized for each speed range for maximum operating efficiency. The number of energized coils are changed dynamically as the speed crosses a threshold between adjacent speed ranges.

Abstract: A rotary electric motor has a stator with a plurality of axially spaced sets of corresponding stator and rotor elements. The stator of each set is an annular ring with poles circumferentially positioned about an axis of rotation. The rotor of each set has a plurality of permanent magnets disposed circumferentially along an annular air gap opposite the stator poles. The permanent magnets of adjacent rotor element sets and/or the poles of adjacent stator sets are offset from each other in the axial direction to cancel the effects of cogging torque produce by each of the sets.

Abstract: A control system for a multiphase permanent magnet motor compensates for physical variations among individual motor phase circuit elements. The control system successively develops a control voltage for switched energization of the motor phase windings that is closely matched with particular parameters of the corresponding windings. The system can be applied to a motor in which each stator phase component comprises a ferromagnetically isolated stator electromagnet, the electromagnet core elements being separated from direct contact with each other and formed with separate phase windings. A digital signal processor may be utilized that applies an algorithm incorporating the parameters as constant values, the parameters for a particular phase being accessed for generating the appropriate control signals for energizing that phase.