Abstract: A method of controlling operation of an electric machine includes: determining a voltage-based torque limit based on a voltage constraint of a direct current (DC) bus supplying power to an inverter for powering the electric machine; determining a motor current-based torque limit based on a motor current limit; determining a supply current-based torque limit based on a supply rating, to supply current to the inverter, of the DC bus; determining a regenerative current-based torque limit based on a receive rating, to receive current from the inverter, of the DC bus; determining a final torque limit based on the voltage-based torque limit, the motor current-based torque limit, the supply current-based torque limit, and the regenerative current-based torque limit; determining a limited command torque based on a torque command and the final torque limit; and calculating at least one current command based on, at least, the limited command torque.

Abstract: A method of controlling operation of an electric machine includes: determining a voltage-based torque limit based on a voltage constraint of a direct current (DC) bus supplying power to an inverter for powering the electric machine; determining a motor current-based torque limit based on a motor current limit; determining a final torque limit based on the voltage-based torque limit and the motor current-based torque limit; determining a limited command torque based on a torque command and the final torque limit; determining an initial current command corresponding to the inverter satisfying a regenerative current limit of the DC bus; and calculating a final current command based on, at least, the limited command torque and the initial current command. The method includes the final current command exceeding the initial current command to cause the electric machine to produce a torque corresponding to the limited torque command.

Abstract: Technical solutions are described for controlling operation of an electric machine such as a permanent magnet synchronous motor (PMSM) drive or motor control system to limit battery current and protect a battery from excessive discharging or charging current from the PMSM drive. Systems and methods employ a torque control algorithm for PMSMs that uses a battery current limit constraint when generating current commands during each of a maximum torque per ampere (MTPA) operation, and maximum torque per voltage (MTPV) operation. Torque search operations are performed in each of the MTPA and MTPV operation regions in a PMSM drive system until current commands are achieved under a given battery current limit constraint and while maintaining maximum voltage utilization throughout all PMSM operation regions.

Abstract: Systems and methods for compensating for a current measurement offset error in a permanent magnet synchronous motor (PMSM) drive are disclosed. The systems and methods include reading an output voltage command signal, extracting a signature of a current measurement offset error from the output voltage command signal, and compensating, based on the signature, for the current measurement offset error in a closed-loop using a feedback path.

Abstract: A method of controlling operation of an electric machine includes: calculating a voltage-based torque limit based on a voltage constraint of a direct current (DC) bus supplying power to an inverter for powering the electric machine; calculating a current-based torque limit based on a motor current limit; determining a final torque limit based on the voltage-based torque limit and the current-based torque limit; determining a limited command torque based on a torque command and the final torque limit; and generating at least one current command based on, at least, the limited command torque. A control system for controlling operation of an electric machine is also provided.

Abstract: A method of controlling operation of an electric machine includes: determining a voltage-based torque limit based on a voltage constraint of a direct current (DC) bus supplying power to an inverter for powering the electric machine; determining a motor current-based torque limit based on a motor current limit; determining a supply current-based torque limit based on a supply rating, to supply current to the inverter, of the DC bus; determining a regenerative current-based torque limit based on a receive rating, to receive current from the inverter, of the DC bus; determining a final torque limit based on the voltage-based torque limit, the motor current-based torque limit, the supply current-based torque limit, and the regenerative current-based torque limit; determining a limited command torque based on a torque command and the final torque limit; and calculating at least one current command based on, at least, the limited command torque.

Abstract: A method of controlling operation of an electric machine includes: determining a voltage-based torque limit based on a voltage constraint of a direct current (DC) bus supplying power to an inverter for powering the electric machine; determining a motor current-based torque limit based on a motor current limit; determining a final torque limit based on the voltage-based torque limit and the motor current-based torque limit; determining a limited command torque based on a torque command and the final torque limit; determining an initial current command corresponding to the inverter satisfying a regenerative current limit of the DC bus; and calculating a final current command based on, at least, the limited command torque and the initial current command. The method includes the final current command exceeding the initial current command to cause the electric machine to produce a torque corresponding to the limited torque command.

Abstract: Systems and methods for detecting a current measurement gain error in a current measurement system is disclosed. The method includes reading an output voltage signal, extracting a signature of a current measurement gain error from the output voltage signal, detecting an existence of the current measurement gain error based on the signature, and responsive to detecting the existence of the current measurement gain error, identifying a diagnostic voltage phase in which the current measurement gain error exists.

Abstract: A system and method for improved anti-windup that minimizes supply current draw under voltage saturated current control operation of synchronous motor drives are provided. The system and method use a voltage limiting module configured to receive a pre-limit voltage command and generate a post-limit voltage command when the motor control system reaches configured threshold; and an anti-windup module configured to determine a voltage difference between the post-limit and pre-limit voltage commands, and compute an anti-windup feedback current using the voltage difference and compensation gains selected to minimize supply current. The compensation gains comprise a gain matrix of values selected to move a motor current trajectory toward a null motor current vector, and the anti-windup module multiplies the gain matrix values by the voltage difference. The anti-windup feedback current and an input current command are then added and provided as an input to the controller.

Abstract: Technical solutions are described for attenuating dither noise in a steering system. An example method includes computing multiple filter parameters, each filter parameter based on a corresponding signal in the steering system. The method further includes determining at least one final filter parameter from the plurality of filter parameters by arbitrating the plurality of filter parameters. The method further includes dynamically configuring a filter using the at least one final filter parameter. Further, the method includes filtering a motor torque command using the filter, a filtered motor torque command being applied to a motor to generate a corresponding amount of torque.

Abstract: Systems and methods for compensating for a current measurement offset error in a permanent magnet synchronous motor (PMSM) drive are disclosed. The systems and methods include reading an output voltage command signal, extracting a signature of a current measurement offset error from the output voltage command signal, and compensating, based on the signature, for the current measurement offset error in a closed-loop using a feedback path.

Abstract: A system and method for improved anti-windup that minimizes supply current draw under voltage saturated current control operation of synchronous motor drives are provided. The system and method use a voltage limiting module configured to receive a pre-limit voltage command and generate a post-limit voltage command when the motor control system reaches configured threshold; and an anti-windup module configured to determine a voltage difference between the post-limit and pre-limit voltage commands, and compute an anti-windup feedback current using the voltage difference and compensation gains selected to minimize supply current. The compensation gains comprise a gain matrix of values selected to move a motor current trajectory toward a null motor current vector, and the anti-windup module multiplies the gain matrix values by the voltage difference. The anti-windup feedback current and an input current command are then added and provided as an input to the controller.

Abstract: Technical solutions are described for controlling operation of an electric machine such as a permanent magnet synchronous motor (PMSM) drive or motor control system to protect against excessive machine current or voltage in a PMSM drive. Systems and methods employ a torque control algorithm for PMSMs that uses the constraints of both machine current and voltage capability in PMSM drives, and online torque command modification according to the maximum allowed torque under these machine current and voltage constraints.

Abstract: Technical solutions are described for controlling operation of an electric machine such as a permanent magnet synchronous motor (PMSM) drive or motor control system to limit battery current and protect a battery from excessive discharging or charging current from the PMSM drive. Systems and methods employ a torque control algorithm for PMSMs that uses a battery current limit constraint when generating current commands during each of a maximum torque per ampere (MTPA) operation, and maximum torque per voltage (MTPV) operation. Torque search operations are performed in each of the MTPA and MTPV operation regions in a PMSM drive system until current commands are achieved under a given battery current limit constraint and while maintaining maximum voltage utilization throughout all PMSM operation regions.

Abstract: Technical solutions are described for a control system that includes a current command module configured to receive a torque command and output a current command for controlling a direct current (DC) motor, and a regenerative current limiting module configured to receive a regenerative current limit as an input and actively compute a motor current limit based on the regenerative current limit, the regenerative current limiting module configured to limit the current command based on the motor current limit.

Abstract: Technical solutions are described for attenuating dither noise in a steering system. An example method includes computing multiple filter parameters, each filter parameter based on a corresponding signal in the steering system. The method further includes determining at least one final filter parameter from the plurality of filter parameters by arbitrating the plurality of filter parameters. The method further includes dynamically configuring a filter using the at least one final filter parameter. Further, the method includes filtering a motor torque command using the filter, a filtered motor torque command being applied to a motor to generate a corresponding amount of torque.

Abstract: Technical solutions are described for providing torque ripple compensation when a motor control system is operating in feedforward mode. An example motor control system includes a feedforward controller that receives a first current command corresponding to an input torque command, and receives a second current command corresponding to a torque ripple. The feedforward controller generates a voltage command based on the first current command and the second current command, the voltage command being applied to a motor.

Abstract: Technical solutions are described for providing torque ripple compensation when a motor control system is operating in feedforward mode. An example motor control system includes a feedforward controller that receives a first current command corresponding to an input torque command, and receives a second current command corresponding to a torque ripple. The feedforward controller generates a voltage command based on the first current command and the second current command, the voltage command being applied to a motor.

Abstract: Technical solutions are described for a control system that includes a current command module configured to receive a torque command and output a current command for controlling a direct current (DC) motor, and a regenerative current limiting module configured to receive a regenerative current limit as an input and actively compute a motor current limit based on the regenerative current limit, the regenerative current limiting module configured to limit the current command based on the motor current limit.