US 2022/0286067 A1 · DRIVE METHODS FOR A THREE-PHASE MOTOR

Abstract

A method of driving a three-phase motor includes, while a first phase is energized, driving a second phase using a first drive function which is sinusoidal. The first phase is switched to a non-energized state and a back electromotive force (BEMF) voltage of the first phase is detected. For at least a portion of a time when the first phase is non-energized the driving of the second phase depends on the output of a second drive function different from the first drive function. The second drive function may be non-sinusoidal and may be a cosine function. The second drive function may drive the second phase when the output of the second drive function is a modulation ratio less than 1. When the output of the second drive function is a modulation ratio greater than or equal to 1 the second phase may be driven to a modulation ratio of 1.

Claims20

Dependent claims

A method of driving a star-connected three-phase motor, comprising:

driving a first phase of the star-connected three-phase motor using a first sinusoidal drive function when all three phases are energized;
driving the first phase using a first non-sinusoidal drive function for at least a portion of a time when one phase other than the first phase is not energized and when the first non-sinusoidal drive function results in a modulation ratio less than 1;
and
driving the first phase to a modulation ratio of 1 for at least a portion of a time when one phase other than the first phase is not energized and when the first non-sinusoidal drive function results in a modulation ratio greater than or equal to 1.

1 more element

A method of driving a star-connected three-phase motor, comprising:

driving a first phase of the star-connected three-phase motor using a first sinusoidal drive function when all three phases are energized;
driving the first phase using a first cosine drive function for at least a portion of a time when one phase other than the first phase is not energized and when the first cosine drive function results in a low torque ripple modulation ratio less than 1;
and
driving the first phase to a low torque ripple modulation ratio of 1 for at least a portion of a time when one phase other than the first phase is not energized and when the first cosine drive function results in a low torque ripple modulation ratio greater than or equal to 1.

1 more element

Dependencies are inferred from the claim text.

Drive methods for a three-phase motor

Life of this patent

Drive methods for a three-phase motor

Life of this patent

Abstract

Claims20