Gm Global Technolgoy Operations, Inc.

Borgwarner Inc.

Dwarakanath V Simili

Anno Yoo

Yo Chan Son

Brent S Gagas

Jihoon Jang

Caleb W Secrest

Bon Ho Bae

Sinisa Jurkovic

Siddharth Ballal

Caleb Wayne Secrest

Aayush Gupta

Gilsu Choi

A method of controlling a motor controlled by a motor controller that includes a complex vector flux regulator (CVλR). The method includes: receiving at a field weakening regulator of the motor controller a modulation index that is a scaled version of an available voltage available to be provided to the motor by a voltage source; comparing the modulation index to a feedback modulation index to produce an error scalar that has a magnitude in a flux domain; determining a final direction (α) of the error scalar in the flux domain; and providing the CVλR with flux commands in the d and q domain based on the error scalar and the direction.

Field weakening regulator for CVFR current regulator

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.

Method for motor and inverter temperature control

A propulsion system for a device having an electric motor configured to selectively provide a first torque contribution to propel the device. At least one sensor is configured to obtain a respective signal related to the electric motor. A controller is in communication with the sensors and configured to determine a magnet flux linkage (&#x3bb;) based in part on the respective signal. The controller has a processor and tangible, non-transitory memory on which instructions are recorded for a method of determining a demagnetized torque capability (T) for the electric motor in real-time. In the event of a threshold level of demagnetization of the electric motor, the method estimates the torque capability in real time of the electric motor, taking the demagnetization level into account. At least one operating parameter of the device is controlled based at least partially on the demagnetized torque capability (T).

Determination of demagnetized torque capability in real-time for electric motor in propulsion system

A current regulator is provided for an electric machine drive system for driving an electric machine. The current regulator includes an adjustable damping module that has a value of virtual damping resistance that is applied at the current regulator. The value of virtual damping resistance is adjustable as a function of sampling frequency. A controller can control the current regulator by determining whether the sampling frequency has changed since a previous execution cycle of the current regulator, and when the sampling frequency has changed since the previous execution cycle, the controller can modify the damping value as a function of the sampling frequency to allow the damping value to change with the sampling frequency. The damping value has a new value of virtual damping resistance that is applied at the current regulator after modifying the damping value. The controller can then execute the current regulator in accordance with the modified damping value to generate the voltage commands.

Methods, systems and apparatus for controlling current supplied to control a machine

A current regulator is provided for an electric machine drive system for driving an electric machine. The current regulator is configurable to operate in a first configuration or a second configuration depending on a synchronous speed of the electric machine. A controller can configure an operational mode of the current regulator by selecting, based on the synchronous speed of the electric machine, either the first configuration of the current regulator or the second configuration of the current regulator as a currently active configuration, and can then execute the current regulator in accordance with the currently active configuration. The first configuration of the current regulator comprises a first set of elements and cross-coupling gain blocks, whereas the second configuration of the current regulator can include the first set of elements without the cross-coupling gain blocks. The first set elements can vary depending on the implementation, but can generally include: summing junctions, integrators, and gain blocks. In one embodiment, the current regulator is configured to operate as a complex vector current regulator when configured in the first configuration, and is configured to operate as a state feedback decoupling (SFbD) current regulator when configured in the second configuration.

A method in a motor controller for an electric motor is disclosed. The method includes receiving a motor current measurement, a motor reference voltage or measured voltage, and an estimated temperature from the electric motor, determining a reference flux linkage estimate (&#x3bb;pm,ref) from a lookup table based on the motor current measurement and the estimated temperature, determining a back-EMF (electromotive force) estimate based on the motor current measurement, the motor voltage and the estimated temperature, determining an observed flux linkage estimate (&#x3bb;pm,obs) from the back-EMF estimate, determining a magnetic strength as a ratio of the observed flux linkage estimate to the reference flux linkage estimate, and determining that a rotor magnet has been demagnetized to an unacceptable level when the magnetic strength is below a threshold level.

Apparatus and method for monitoring magnet flux degradation of a permanent magnet motor

An electric machine assembly includes an electric machine having a stator configured to have a stator current and a controller configured to receive a torque command (T). The controller stores a modulation flag (F) and a six step active flag (F), each having a respective status. The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method of controlling a six step pulse width modulation operation in the assembly. The controller is programmed to determine the respective status of a six step active flag (F) based at least partially on the torque command (T) and the respective status of the modulation flag (F). The controller is configured to control at least one operating parameter of the electric machine based at least partially on the respective status of the six step active flag (F).

Control of six step pulse width modulation with flux weakening

An electric machine assembly includes an electric machine having a stator configured to have a stator current and a controller configured to receive a torque command (T). The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method of modifying the stator current for enhanced flux weakening. The controller is programmed to obtain a base stator current [I, I] from a look-up table based at least partially on the torque command (T). The controller is programmed to obtain a characteristic angle (&#x3b8;, i=1, 2, 3) based at least partially on a value of the torque command (T) and the base stator current [I, I]. A stator current modifier [&#x394;I, &#x394;I] is obtained based at least partially on the characteristic angle (&#x3b8;, i=1, 2, 3) and a flux weakening factor (&#x394;I) such that: &#x394;I=(&#x394;I*cosine (&#x3b8;)) and &#x394;I=(&#x394;I*sine (&#x3b8;)).

Modification of stator current for enhanced flux weakening

An electric machine assembly has an electric machine having a stator and a rotor. The rotor has a rotor temperature and is configured to rotate at a rotor speed (&#x3c9;). The stator has stator windings at a stator winding temperature (t) and the electric machine defines a number of pole pairs (P). A controller is operatively connected to the electric machine and is configured to receive a torque command (T*). The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a total permanent magnetic flux (&#x3c8;) as a function of the rotor temperature. Execution of the instructions by the processor causes the controller to determine a high-speed magnetic flux factor (&#x3c8;) and a low-speed magnetic flux factor (&#x3c8;).

Determination of permanent magnetic flux in an electric machine

An electric machine assembly includes an electric machine having a stator and a rotor. The stator has stator windings at a stator winding temperature (t) and the rotor is configured to rotate at a rotor speed (&#x3c9;). A controller is operatively connected to the electric machine and has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining stator winding resistance. The controller is configured to determine a high-speed resistance factor (r) which is based at least partially on the torque command (T*), the stator winding temperature (t), the rotor speed (&#x3c9;), a characterized torque error and the number of pole pairs (P). The controller may determine a total resistance value (R) based on a weighting factor (k), the high-speed resistance factor (r) and the low-speed resistance factor (r).

Determination of stator winding resistance in an electric machine

An electric motor system includes a motor configured to produce a torque signal in response to a torque command. The torque signal has a fundamental frequency component, a first ripple harmonic and a second ripple harmonic. The first ripple harmonic is an integer multiple of the fundamental frequency component. The second ripple harmonic is an integer multiple of the first ripple harmonic. A system and method is provided to generate a ripple reduction signal in response to the torque command that simultaneously cancels the first and the second ripple harmonic in the torque signal. The second ripple harmonic may be canceled with the first ripple harmonic by being projected onto the first ripple harmonic through a transformation matrix.

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Oakland Township, MI, United States of America

Dwarakanath V Simili