THREE-PHASE AC MOTOR SYSTEM, DRIVE UNIT FOR THE THREE-PHASE AC MOTOR SYSTEM AND CONTROL METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a three-phase AC motor system capable of suppressing the generation of lower-order harmonics and carrier harmonics and of inhibiting generation of torque pulsation, with high efficiency.

SOLUTION: This three-phase AC motor system includes: a three-phase AC motor, having four groups of three-phase stator windings attached to a stator core, each electrical angle of which has a phase difference of 15 degrees; and four groups of inverters arranged so as to respectively become as a single pair with the four groups of three-phase stator windings. In the phase differences of modulating signals for determining the voltage chopped phases of the inverters, the second group with a phase difference of 15 degrees from the first group of windings has a phase difference of 135 degrees; the third group with a phase difference of 30 degrees from the first group has a phase difference of 270 degrees; and the fourth group with a phase difference of 45 degrees from the first group has a phase difference of 45 degrees. Alternatively, the second group with a phase difference of 15 degrees from the first group has a phase difference of 225 degrees; the third group with a phase difference of 30 degrees from the first group has a phase difference of 90 degrees; and the fourth group with a phase difference of 45 degrees from the first group has a phase difference of 315 degrees.

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