Method and system for improved closed loop control of sensorless brushless DC motors
AssigneeInternational Business Machines Corporation
InventorTimothy M. Trifilo
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Abstract
A method for electronically commutating a motor having a plurality of phase windings associated therewith is disclosed. In an exemplary embodiment, the method includes sensing a back electromotive force (BEMF) generated by each of the phase windings, and scaling the magnitude of the sensed BEMF values for each of the phase windings to a normalized value to produce gain corrected BEMF signals. The gain corrected BEMF signals are then used to determine a rotor position of the motor.
Claims14
A method for electronically commutating a motor having a plurality of phase windings associated therewith, the method comprising:
- sensing a back electromotive force (BEMF) generated by each of the phase windings;
- and
- scaling the magnitude of sensed BEMF values for each of the phase windings to a normalized value to produce gain corrected BEMF signals using an automatic gain control circuit;
- wherein said gain corrected BEMF signals are used to determine a rotor position of the motor.
A control circuit for a sensorless brushless motor, comprising:
- a controller for receiving a sensed back electromotive force (BEMF) generated by each of a plurality of phase windings of the motor;
- and
- an automatic gain control circuit for scaling the magnitude of sensed BEMF values for each of the phase windings to a normalized value to produce gain corrected BEMF signals;
- wherein said gain corrected BEMF signals are used by said controller to determine a rotor position of the motor.
A sensorless brushless motor, comprising:
- a plurality of phase windings energized by a direct current source;
- an inverter for sequentially applying phase current from said direct current source through selected pairs of phase windings;
- a controller for receiving a sensed back electromotive force (BEMF) generated by each of said plurality of phase windings of the motor, said controller providing corresponding control signals to control switching of said inverter;
- and
- an automatic gain control circuit for scaling the magnitude of sensed BEMF values for each of said plurality of phase windings to a normalized value to produce gain corrected BEMF signals;
- wherein said gain corrected BEMF signals are used by said controller to determine a rotor position of the motor.
Dependencies are inferred from the claim text.