Universal adaptive torque control for pm motors for field-weakening region operation

A motor controller comprising:

• control circuitry configured to generate a control signal for driving a three phase inverter based at least in part on a value of a normalized direct-axis current, wherein the control circuitry is configured to determine the value of the normalized direct-axis current based on a normalized torque command, a stator frequency, a rated voltage of the motor, a characteristic current of the motor, a rotor flux of the motor, and an inductance ratio value of the motor.

A computer memory device for use in controlling a permanent magnet motor in above base speed operation comprising:

• a machine readable medium;
• and
• a lookup table encoded on the machine readable medium including a plurality of normalized values for optimum direct-axis current, wherein each of the plurality of normalized values for optimum direct-axis current corresponds respectively to a value for optimum direct-axis current in a permanent magnet motor when multiplied by a characteristic current of the permanent magnet motor.