Determining motor position with complementary drive and detect and slight move
AssigneeAllegro MicroSystems, LLC
InventorsYisong Lu, Lyndon Ambruson
Life of this patent
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Abstract
Methods and apparatus for determining a position of a rotor in a three-phase motor by determining first and second ones of sectors in which a first one of the magnetic poles of the rotor may be positioned by respectively driving phase pairs complementary signals and examining a voltage of a floating one of the phases. Embodiments can include applying torque to the motor by driving at least one phase pair with respective signals aligned in phase and unequal duty cycles to move the rotor a given amount from the rotor position in the first or second ones of the sectors for determining the position of the rotor.
Claims21
A method of determining a position of a rotor in a three-phase motor having phase A, phase B, and phase C, comprising:
- determining first and second ones of sectors in which a first one of the magnetic poles of the rotor may be positioned, wherein the first and second ones of the sectors are oppositely located, by respectively driving phase pairs A-B, A-C, and B-C with complementary signals and examining a voltage of a floating one of the phases;
- and
- applying torque to the motor by driving at least one phase pair with respective signals aligned in phase and unequal duty cycles to move the rotor a given amount from the rotor position in the first or second ones of the sectors for determining the position of the rotor.
A system for determining position of a rotor of a three-phase motor, comprising:
- a first module to generate drive signals for the three-phase motor;
- a second module configured to determine first and second ones of sectors in which a first one of the magnetic poles of the rotor may be positioned, wherein the first and second ones of the sectors are oppositely located, by driving phase pairs A-B, A-C, and B-C with complementary signals and examining a voltage of a floating one of the phases;
- and
- a third module configured to apply torque to the motor by driving at least one phase pair with respective signals aligned in phase and unequal duty cycles to move the rotor a given amount from the rotor position in the first or second ones of the sectors for determining the position of the rotor.
Dependencies are inferred from the claim text.