Harmonic torque ripple reduction at low motor speeds
First Claim
1. A method for reducing torque ripple in an electric motor for use in an electric motor drive system for a vehicle, wherein the electric motor is coupled to an inverter, which is coupled to a current regulated control module, wherein the inverter is configured to drive the electric motor, the method comprising:
- receiving a torque command;
determining a cancellation current command based on the torque command;
generating a harmonic cancellation command based on the cancellation current command, wherein the harmonic cancellation command is generated to compensate for a phase shift and an attenuation introduced by the current regulated control module; and
providing the harmonic cancellation command to the current regulated control module, wherein the current regulated control module is configured to control the inverter in response to the harmonic cancellation command and the torque command.
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Accused Products
Abstract
Methods and systems are provided for reducing torque ripple in an electric motor. A method comprises receiving a torque command and determining a cancellation current command based on the torque command. The method further comprises generating a harmonic cancellation command based on the cancellation current command, wherein the harmonic cancellation command compensates for a phase shift and an attenuation introduced by a current regulated control module coupled to an inverter coupled to the electric motor. The method further comprises providing the harmonic cancellation command to the current regulated control module, wherein the current regulated control module is configured to control the inverter in response to the harmonic cancellation command and the torque command.
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Citations
20 Claims
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1. A method for reducing torque ripple in an electric motor for use in an electric motor drive system for a vehicle, wherein the electric motor is coupled to an inverter, which is coupled to a current regulated control module, wherein the inverter is configured to drive the electric motor, the method comprising:
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receiving a torque command; determining a cancellation current command based on the torque command; generating a harmonic cancellation command based on the cancellation current command, wherein the harmonic cancellation command is generated to compensate for a phase shift and an attenuation introduced by the current regulated control module; and providing the harmonic cancellation command to the current regulated control module, wherein the current regulated control module is configured to control the inverter in response to the harmonic cancellation command and the torque command. - View Dependent Claims (2, 3, 4, 5)
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6. A method for reducing torque ripple in an electric motor in response to a torque command, wherein the electric motor is coupled to an inverter, which is coupled to a current regulated control module, wherein the inverter is configured to drive the electric motor, the method comprising:
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determining a harmonic cancellation command based on the torque command, wherein the harmonic cancellation command is adjusted to compensate for a phase shift introduced by the current regulated control module; and providing the harmonic cancellation command to the current regulated control module. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A controller for reducing torque ripple in an electric motor in response to a torque command, the electric motor being coupled to an inverter, the controller comprising:
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a current regulated control module, wherein the current regulated control module generates control signals for the inverter in response to the torque command; and a harmonic cancellation command block coupled to the current regulated control module, the harmonic cancellation command block being configured to generate a harmonic cancellation command for the current regulated control module to reduce a torque ripple harmonic, wherein the harmonic cancellation command is generated to compensate for a phase shift introduced by the current regulated control module. - View Dependent Claims (20)
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Specification