Method and Apparatus for Adjusting Motor Commutation Phase and Period
AssigneeThe Boeing Company
InventorsDouglas Conrad Cameron, Kevin T. Colangelo, Suhat Limvorapun
Life of this patent
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Abstract
A method and apparatus for controlling commutation of a motor. A voltage is measured at each of a plurality of windings of a motor using an electric circuit. A controller computes an overall back electromotive force for the motor using the voltage measured at each winding in the plurality of windings. The controller generates a result having either a first value or a second value based on the overall back electromotive force. The controller adjusts the commutation phase and the commutation period of the motor using the result.
Claims21
An apparatus comprising:
- an electric circuit that measures a voltage at each of a plurality of windings of a motor;
- and
- a controller that is connected to the electric circuit and that:
- computes an overall back electromotive force for the motor using the voltage measured at each winding in the plurality of windings,
- generates a value based on the overall back electromotive force,
- adjusts a phase counter by adding the value and a constant to the phase counter,
- adjusts a commutation period by subtracting the value from the commutation period,
- compares the phase counter to the commutation period after adjusting the phase counter and the commutation period, and
- commutates the motor in response to a determination that the phase counter is greater than or equal to the commutation period.
(canceled)
A method for controlling commutation of a motor, the method of comprising:
- measuring a voltage at each of a plurality of windings of the motor using an electric circuit;
- computing, by a controller, an overall back electromotive force for the motor using the voltage measured at each winding in the plurality of windings;
- generating, by the controller, a value based on the overall back electromotive force;
- adjusting, by the controller, a phase counter by adding the value and a constant to the phase counter;
- adjusting, by the controller, a commutation period by subtracting the result from the commutation period;
- comparing the phase counter to the commutation period after adjusting the phase counter and the commutation period;
- and
- commutating the motor in response to a determination that the phase counter is greater than or equal to the commutation period.
(canceled)
A method for performing sensorless commutation of a motor, the method of comprising:
- receiving, from a voltage measurement system that is connected to an electrical ground, a first phase voltage, a second phase voltage, and a third phase voltage measured at a first winding, a second winding, and a third winding, respectively, of the motor;
- computing an overall back electromotive force for the motor using the first phase voltage, the second phase voltage, and the third phase voltage;
- generating a first value when the overall back electromotive force is not positive and a second value when the overall back electromotive force is positive;
- updating a phase counter by decreasing the phase counter using the result first value when the overall back electromotive force is not positive and by increasing the phase counter using the second value when the overall back electromotive force is positive;
- updating a period adjustment by increasing the period adjustment using the first value when the overall back electromotive force is not positive and by decreasing the period adjustment using the second value when the overall back electromotive force is positive;
- computing a new commutation period for the motor using the period adjustment and a baseline commutation period for the motor;
- comparing the phase counter to the new commutation period;
- and
- commutating the motor in response to a determination that the phase counter is greater than the new commutation period.
Dependencies are inferred from the claim text.