Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. A position sensor is adapted to determine a rotor position of the electric motor. The system includes a controller having instructions recorded for determining the rotor position when a sensor fault condition is detected. The controller is adapted to selectively command injection of a voltage signal in a direct magnetic axis in a synchronous reference frame when a motor speed of the electric motor is below a predefined motor speed threshold and the sensor fault condition is detected. The rotor position is estimated based in part on a motor current response to the voltage signal. The voltage signal is defined by an alternating periodic shape having respective constant segments in each of a plurality of control periods, the respective constant segments being discontinuous between the control periods.

Abstract: A method and system are contemplated for determining a final speed and position of a motor used in an electric vehicle. The final speed and position is calculated as a function of a sensed position when a resolver of a position system is available and as a function of a sensorless position when the resolver is unavailable.

Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. A position sensor is adapted to determine a rotor position of the electric motor. The system includes a controller having instructions recorded for determining the rotor position when a sensor fault condition is detected. The controller is adapted to selectively command injection of a voltage signal in a direct magnetic axis in a synchronous reference frame when a motor speed of the electric motor is below a predefined motor speed threshold and the sensor fault condition is detected. The rotor position is estimated based in part on a motor current response to the voltage signal. The voltage signal is defined by an alternating periodic shape having respective constant segments in each of a plurality of control periods, the respective constant segments being discontinuous between the control periods.

Abstract: A vehicle is described that includes a multi-mode powertrain system having a first drive unit and a second drive unit. A controller is arranged to monitor the high-voltage DC power bus and is in communication with and operatively connected to first and second inverters. The controller is able to detect operation of one of the first inverter or the second inverter in an uncontrolled generating (UCG) mode, determine a driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode, and determine a compensating torque that is needed to counteract the driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode. The controller can further operate to detect a fault that may induce unintended lateral motion (ULM), and control torque outputs of the inverters based thereon.

Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. The electric motor includes a stator and a rotor with one or more permanent magnets. A controller is in communication with the electric motor and has recorded instructions for a method for minimizing demagnetization in the one or more permanent magnets. The controller is adapted to select a starting point and an intermediate point on a current trajectory in a stator current graph. The controller is adapted to obtain a final point on the stator current trajectory based on a comparison of the intermediate point and a predetermined voltage limit. A demagnetized torque capability is generated based on the final point on the current trajectory.

Abstract: A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

Abstract: A method for estimating a magnet temperature of a rotor magnet within a rotary electric machine includes, while a rotor of the electric machine is stationary, injecting a high-frequency voltage component onto a control voltage of the electric machine, via a controller, to generate an adjusted voltage command, and extracting a high-frequency component of a resulting current as an extracted high-frequency component. The method also includes calculating an inductance value of the electric machine using the extracted high-frequency component of the resulting current. The magnet temperature is estimated using the calculated inductance value and an angular position of the rotor. The method includes controlling an operation of the electric machine using the estimated magnet temperature. An electric powertrain uses the electric machine and controller noted above.

Abstract: A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

Abstract: A vehicle is described that includes a multi-mode powertrain system having a first drive unit and a second drive unit. A controller is arranged to monitor the high-voltage DC power bus and is in communication with and operatively connected to first and second inverters. The controller is able to detect operation of one of the first inverter or the second inverter in an uncontrolled generating (UCG) mode, determine a driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode, and determine a compensating torque that is needed to counteract the driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode. The controller can further operate to detect a fault that may induce unintended lateral motion (ULM), and control torque outputs of the inverters based thereon.

Abstract: A method, system, and apparatus for controlling and regulating operation of a permanent magnet rotary electric machine including a stator and a rotor includes determining a first reactive power term associated with the electric machine based upon voltage, and determining a second reactive power term associated with the electric machine based upon flux. A first motor temperature associated with the electric machine is determined based upon the first and second reactive power terms, and power output from the permanent magnet electric machine is controlled based upon the first motor temperature.

Abstract: A resolver disposed to monitor a rotatable member is described, along with an associated method for evaluating an output signal therefrom. The method for monitoring the resolver includes supplying an excitation signal to the resolver, and monitoring, at an oversampling rate, first and second output signals from the resolver. An oversampling routine is executed to determine averages of the first and second output signals from the resolver. A demodulation angle error is determined based upon the first and second output signals from the resolver, and provided as feedback. A position of the resolver is also determined based upon the first and second output signals from the resolver.

Abstract: A propulsion system having an electric motor and corresponding method. A controller is configured to receive a torque request and selectively command the electric motor. The controller has a processor and tangible, non-transitory memory on which instructions are recorded for a method of generating an auxiliary power. The controller is configured to obtain a desired auxiliary power and a delta factor (?). The delta factor is set as a speed modifier (??=?) when the cosine of an angle (?), between a constant torque unit vector and a decreasing voltage ellipse unit vector, is less than a predefined threshold. A modified rotor speed is obtained as a sum of an original rotor speed and a speed modifier (??). The controller is configured to obtain modified stator current commands based on the modified rotor speed and torque request. The auxiliary power is generated by commanding the modified stator current commands.

Abstract: A method, system, and apparatus for controlling and regulating operation of a permanent magnet rotary electric machine including a stator and a rotor includes determining a first reactive power term associated with the electric machine based upon voltage, and determining a second reactive power term associated with the electric machine based upon flux. A first motor temperature associated with the electric machine is determined based upon the first and second reactive power terms, and power output from the permanent magnet electric machine is controlled based upon the first motor temperature.

Abstract: A method for estimating a magnet temperature of a rotor magnet within a rotary electric machine includes, while a rotor of the electric machine is stationary, injecting a high-frequency voltage component onto a control voltage of the electric machine, via a controller, to generate an adjusted voltage command, and extracting a high-frequency component of a resulting current as an extracted high-frequency component. The method also includes calculating an inductance value of the electric machine using the extracted high-frequency component of the resulting current. The magnet temperature is estimated using the calculated inductance value and an angular position of the rotor. The method includes controlling an operation of the electric machine using the estimated magnet temperature. An electric powertrain uses the electric machine and controller noted above.

Abstract: A propulsion system having an electric motor and corresponding method. A controller is configured to receive a torque request and selectively command the electric motor. The controller has a processor and tangible, non-transitory memory on which instructions are recorded for a method of generating an auxiliary power. The controller is configured to obtain a desired auxiliary power and a delta factor (?). The delta factor is set as a speed modifier (??=?) when the cosine of an angle (?), between a constant torque unit vector and a decreasing voltage ellipse unit vector, is less than a predefined threshold. A modified rotor speed is obtained as a sum of an original rotor speed and a speed modifier (??).The controller is configured to obtain modified stator current commands based on the modified rotor speed and torque request. The auxiliary power is generated by commanding the modified stator current commands.

Abstract: A resolver disposed to monitor a rotatable member is described, along with an associated method for evaluating an output signal therefrom. The method for monitoring the resolver includes supplying an excitation signal to the resolver, and monitoring, at an oversampling rate, first and second output signals from the resolver. An oversampling routine is executed to determine averages of the first and second output signals from the resolver. A demodulation angle error is determined based upon the first and second output signals from the resolver, and provided as feedback. A position of the resolver is also determined based upon the first and second output signals from the resolver.

Abstract: A method of controlling an interior permanent magnet (IPM) motor includes receiving a motor torque command, and selecting a nominal d-axis current and a nominal q-axis current stored in a first lookup table. The nominal d-axis current and the nominal q-axis current correspond with a predetermined efficiency of the IPM motor at a nominal temperature and are based on at least the motor torque command and magnetic flux at a nominal temperature of the IPM motor. A d-axis adjustment current and a q-axis adjustment current are then selected from a stored second lookup table. The adjustment currents correspond with the predetermined efficiency of the IPM motor and are based at least on the magnetic flux and an operating temperature of the IPM motor. A corrected d-axis current and a corrected q-axis current are commanded. The corrected currents are the sum of the respective nominal current and adjustment current.

Abstract: An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the d- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

Abstract: An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the B- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

Abstract: A method for regulating operation of an induction motor having a rotor includes calculating a rotor flux angle error value, via a flux observer of a controller, using estimated d-axis and q-axis flux values of the rotor, estimating rotor position using a position observer of the controller, and calculating slip position of the rotor using d-axis and q-axis stator currents. The method also includes estimating a rotor flux angle as a function of slip position and estimated rotor position, calculating a corrected rotor flux angle by selectively adding the rotor flux angle error value to the estimated rotor flux angle, and controlling output torque of the motor using the corrected rotor flux angle. A logic switch may be used to selectively add the rotor flux angle.