Method of identifying parameters of a motor system

A non-transitory computer program comprising computer code stored on a non-transitory computer readable medium, the computer code when executed by a processing circuitry of a control system causes the control system to perform the steps of a method of identifying parameters of a motor system that includes an electric motor assembly, the method including:

• a) sweeping a frequency of an oscillating reactive torque injected into the electric motor,
• b) determining a natural frequency of the motor system, the natural frequency being the frequency at which the oscillating reactive torque produces a maximum amplitude of a vibration-related parameter obtained based on vibration-related measurements by sensors mounted to the electrical motor,
• c) incrementally increasing a magnitude of reactive torque oscillating at the natural frequency, injected to the electric motor,
• d) obtaining a magnitude of the vibration-related parameter for each magnitude of the reactive torque injected in step c),
• e) determining, for each magnitude of the injected reactive torque, a gain, and a phase response of the motor system, the gain being determined based on the magnitude of the injected reactive torque and the corresponding magnitude of the vibration-related parameter, and the phase response being determined based on a phase angle of the injected reactive torque and a phase angle of the corresponding vibration-related parameter, and
• f) controlling, by the control system, injected reactive torque based on the natural frequency, the gains, and the phase responses in a control scheme to reduce vibrations in the electric motor assembly.

A control system comprising:

• a storage medium including a computer code, and
• processing circuitry configured to execute the computer code, causing the control system to perform a method of identifying parameters of a motor system that includes an electric motor assembly, the method including:
• a) sweeping a frequency of an oscillating reactive torque injected into the electric motor,
• b) determining a natural frequency of the motor system, the natural frequency being the frequency at which the oscillating reactive torque produces a maximum amplitude of a vibration-related parameter obtained based on vibration-related measurements by sensors mounted to the electrical motor,
• c) incrementally increasing a magnitude of reactive torque oscillating at the natural frequency, injected to the electric motor,
• d) obtaining a magnitude of the vibration-related parameter for each magnitude of the reactive torque injected in step c),
• e) determining, for each magnitude of the injected reactive torque, a gain, and a phase response of the motor system, the gain being determined based on the magnitude of the injected reactive torque and the corresponding magnitude of the vibration-related parameter, and the phase response being determined based on a phase angle of the injected reactive torque and a phase angle of the corresponding vibration-related parameter, and
• f) controlling, by the control system, injected reactive torque based on the natural frequency, the gains, and the phase responses in a control scheme to reduce vibrations in the electric motor assembly.

A motor system comprising:

• an electric motor assembly including an electric motor, and
• a control system having:
• a storage medium including a computer code, and
• processing circuitry configured to execute the computer code, causing the control system to perform a method of identifying parameters of the motor system, the method including:
• a) sweeping a frequency of an oscillating reactive torque injected into the electric motor,
• b) determining a natural frequency of the motor system, the natural frequency being the frequency at which the oscillating reactive torque produces a maximum amplitude of a vibration-related parameter obtained based on vibration-related measurements by sensors mounted to the electrical motor,
• c) incrementally increasing a magnitude of reactive torque oscillating at the natural frequency, injected to the electric motor,
• d) obtaining a magnitude of the vibration-related parameter for each magnitude of the reactive torque injected in step c),
• e) determining, for each magnitude of the injected reactive torque, a gain, and a phase response of the motor system, the gain being determined based on the magnitude of the injected reactive torque and the corresponding magnitude of the vibration-related parameter, and the phase response being determined based on a phase angle of the injected reactive torque and a phase angle of the corresponding vibration-related parameter, configured to control the electric motor, and
• f) Controlling, by the control system, injected reactive torque based on the natural frequency, the gains, and the phase responses in a control scheme to reduce vibrations in the electric motor assembly.