Linearity for field weakening in an interior permanent magnet machine
AssigneeGM Global Technology Operations LLC
InventorsGabriel Gallegos-Lopez, Yo Chan Son, Milun Perisic, Silva Hiti
Life of this patent
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Abstract
Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. As a result, torque linearity is maintained when the electric machine operates in the field weakening region.
Claims22
A method for linearizing torque generated by an electric machine, the method comprising:
- generating, based on d-axis and q-axis voltage commands, a first adjusting current command;
- multiplying the first adjusting current command by a gain to generate an output current command, wherein the gain is a variable that is influenced by torque and q-axis components of stator current;
- and
- limiting the output current command to generate a second adjusting current command.
A torque linearity control architecture for an electric machine, the control architecture comprising:
- a field weakening control loop that generates a first adjusting current command based on d-axis and q-axis voltage commands;
- a gain module configured to multiply the first adjusting current command by a gain to generate an output current command, wherein the gain is a variable that is influenced by torque and q-axis components of stator current;
- and
- a limiter module coupled to the gain module, the limiter module being configured to generate a second adjusting current command by limiting the output current command.
A method for linearizing torque generated by an electric machine, the method comprising:
- generating, based on first and second voltage commands, a first adjusting current command;
- multiplying the first adjusting current command by a gain to generate an output current command, wherein the gain is a variable that is influenced by torque and q-axis components of stator current;
- and
- limiting the output current command to generate a second adjusting current command.
A torque linearity control architecture for an electric machine, the control architecture comprising:
- a field weakening control loop that generates a first adjusting current command based on d-axis and q-axis voltage commands;
- a gain module configured to multiply the first adjusting current command by a gain to generate an output current command;
- a limiter module coupled to the gain module, the limiter module being configured to generate a second adjusting current command by limiting the output current command;
- a look-up table module that receives a torque command, a rotor angular velocity, and a DC-link voltage, and that generates a q-axis current command and a d-axis current command;
- a first adder that generates a q-axis adjusted current command based on the first adjusting current command and the q-axis current command;
- and
- a second adder coupled to the limiter module and configured to receive the second adjusting current command as one input and the d-axis current command as another input, wherein the adder adds the second adjusting current command to the d-axis current command to generate a d-axis adjusted current command.
Dependencies are inferred from the claim text.