Abstract:
A method of controlling an electrical machine. The electrical machine includes a stator having a core and a plurality of windings, and a rotor disposed adjacent to the stator to interact with the stator. The method includes configuring an amplitude value and frequency values of a three-phase alternating current (AC) voltage startup signal having an amplitude and a frequency, providing the three-phase alternating current (AC) voltage startup signal to the plurality of windings, and altering the frequency of the three-phase AC voltage startup signal according to a preprogrammed frequency ramp function defined by the frequency values. The method further includes discontinuing the three-phase AC voltage startup signal after the frequency ramp function has completed, and switching to a back electromotive force (BEMF) control mode after discontinuing the three-phase AC voltage startup signal.
Abstract:
A method for fabricating a rotor for an electric motor is provided. The method includes the steps of fabricating a first set of rotor parts for use in a motor having a first frame size and fabricating a second set of rotor parts for use in a motor having a second frame size. The second frame size is substantially different from the first frame size. The method further includes the steps of fabricating a third set of rotor parts for use in the motor having the first frame size and for use in the motor having the second frame size, ascertaining the desired motor frame size, and selecting one of the first set of rotor parts and the second set of rotor parts in accordance with desired motor frame size. The method also includes the steps of selecting the third set of rotor parts and assembling a rotor with one of the first set of rotor parts and the second set of rotor parts and with the third set of rotor parts, such that a rotor for use with the desired motor frame size is substantially provided.
Abstract:
A permanent magnet rotor is described. The permanent magnet rotor includes at least one permanent magnet and a rotor core including a first end and a second end. The rotor core includes at least one inner wall that defines a permanent magnet opening configured to receive the at least one permanent magnet. The rotor core further includes at least one permanent magnet retention feature extending substantially radially from the at least one inner wall and configured to maintain a position of the at least one permanent magnet with respect to the at least one permanent magnet opening.
Abstract:
An axial flux electric machine and associated method of use that includes a shaft, a rotor attached to the shaft, a plurality of permanent magnets positioned underneath the rotor, an electrical winding positioned below the plurality of permanent magnets, a stator that encircles the shaft that is located below the rotor, a first bearing assembly located below the stator and encircling the shaft of the rotor, a second bearing assembly located below the first bearing assembly and encircling the shaft, and a spring mechanism, located between the first bearing assembly and the second bearing assembly, to distribute load placed on the shaft between the first bearing assembly and the second bearing assembly.
Abstract:
A system and method of controlling an electric motor using a motor controller are provided. The system includes an electric motor controller configured to be coupled to an electric motor and to control the electric motor to produce approximately constant average torque. The controller includes a rectifier configured to convert an AC input voltage to a pulsing DC voltage, a DC link electrically coupled to the rectifier, an inverter electrically coupled to the DC link and configured to generate a three phase AC voltage to drive the electric motor, and a controller configured to receive a measurement of a motor current value for the motor, estimate a torque generated in the electric motor using the measurement of the instantaneous motor current value, and generate a real-time current demand signal using the estimated torque value, the real-time current demand signal compensating the motor controller to produce a substantially constant average motor output torque.
Abstract:
An electric motor that includes an electronic motor controller is described. The electronic motor controller includes a motor management circuit and a power supply circuit physically separate from the motor management circuit. The motor management circuit includes an insulated metal substrate, driver components operably attached to the insulated metal substrate and operable to provide output signals for application to windings of the electric motor, at least one current sensor operable for sensing an amount of current applied to the windings of and electric motor, and at least one control device operably attached to the insulated metal substrate for controlling operation of the driver components. The power supply circuit includes a composite circuit card and power processing components operably attached to the circuit card and operable to convert an input voltage into at least one output voltage to be supplied to the motor management circuit.
Abstract:
Drive circuits that provide power factor correction and input current waveform shaping for controlling the speed and torque in a switched reluctance machine (SRM). The machine's phase windings are split into two segments, one of which is used for active power factor correction, input ac current waveform shaping and partial torque generation and the other of which is used for torque generation.
Abstract:
A manual valve operator with override clutch apparatus is disclosed for selectively actuating a valve. The apparatus includes an operator housing defining an enclosure. An input shaft is rotatably supported by the housing and a worm wheel has a first and a second side, the second side of the worm wheel defining a clutch drive. The worm wheel is disposed within the housing and intermeshes with the input shaft such that when the input shaft is driven, the input shaft drives the worm wheel and the clutch drive about a rotational axis. A sleeve has an outer surface which defines an annular groove. The sleeve has a driven end and an output end. The driven end of the sleeve cooperates with the clutch drive of the worm wheel for selective engagement of the clutch drive and the driven end of the sleeve. A clutch actuating handle is rotatably supported by the housing. The clutch actuating handle has a first and a second end. The second end of the clutch actuating handle defines an offset clutch driver which slidably cooperates with the annular groove of the sleeve. The arrangement is such that when the handle is rotated relative to the housing, the offset clutch driver rides within the annular groove for urging the sleeve axially along the rotational axis so that in a first axial disposition of the sleeve, the clutch drive of the worm wheel and the driven end of the sleeve are engaged relative to each other so that the sleeve is rotated by the worm wheel about the rotational axis. However, when the sleeve is disposed in a second axial disposition thereof, the driven end of the sleeve is disengaged relative to the clutch drive of the worm wheel. A driven shaft has a first and a second end, the second end of the driven shaft being connected to the valve. The driven shaft extends coaxially through the sleeve, the driven shaft being keyed to the sleeve such that relative rotation between the sleeve and the driven shaft is inhibited while axial movement of the sleeve relative to the driven shaft is permitted. The arrangement is structured such that when the sleeve is in the first axial disposition thereof, the worm wheel drivably rotates the sleeve so that the rotating sleeve rotatably drives the driven shaft for actuating the valve. Also, when the sleeve is in the second axial disposition thereof, the driven end of the sleeve is disengaged from the clutch drive of the worm wheel so that rotation of the sleeve and the driven shaft keyed thereto by the input shaft is inhibited.
Abstract:
Methods and systems for starting an electric motor using a motor controller including a processor are provided. The method includes determining if the electric motor is operating, increasing a failed start counter if the electric motor is determined not to be operating, determining a reverse rotation by comparing a failed start counter to a predetermined threshold, and applying a reverse rotation start routine to the electric motor when a reverse rotation is determined.
Abstract:
A system and method of controlling an electric motor using a motor controller are provided. The system includes an electric motor controller configured to be coupled to an electric motor and to control the electric motor to produce approximately constant average torque. The controller includes a rectifier configured to convert an AC input voltage to a pulsing DC voltage, a DC link electrically coupled to the rectifier, an inverter electrically coupled to the DC link and configured to generate a three phase AC voltage to drive the electric motor, and a controller configured to receive a measurement of a motor current value for the motor, estimate a torque generated in the electric motor using the measurement of the instantaneous motor current value, and generate a real-time current demand signal using the estimated torque value, the real-time current demand signal compensating the motor controller to produce a substantially constant average motor output torque.