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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsTomokazu Nakamura, Noriyoshi Nishiyama, Yasufumi Ikkai
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Torque ripples of a motor having interior permanent magnets can be reduced through the following method and the torque ripple controller using the same method: first, drive the motor having a plurality of phase windings and interior permanent magnets with a basic current supply circuit which outputs a basic current having a predetermined waveform, then store torque ripple waves produced in the running motor or obtained through a numerical analysis into a torque-ripple-wave-memory, next, compensate the torque ripple wave tapped off from the memory according to a prepared torque ripple compensation pattern and transform it to a torque compensation waveform with a torque-compensation-waveform-producing-circuit, further, multiply the torque compensation waveform tapped off from the waveform producing circuit by the basic current with a multiplier to output a torque ripple control current, and, supply the torque ripple control current to the plurality of phase windings shifting a phase by a predetermined electrical angle sequentially.
A method of controlling a torque ripple of a motor having an interior permanent magnet and a plurality of phase windings comprising the steps of:
A method of controlling a torque ripple of a motor having an interior permanent magnet and a plurality of phase windings comprising the steps of:
A torque ripple controller for a motor having an interior permanent magnet and a plurality of phase windings, said torque ripple controller comprising:
A torque ripple controller for a motor having an interior permanent magnet and a plurality of phase windings, said torque ripple controller comprising:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Term ended 29 Jul 2018 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a driving motor utilized in an electric vehicle and the like, more specifically, a controlling method of a torque ripple of the motor incorporating an interior permanent magnet and a controller using the same method.
Regarding a motor having permanent magnets pasted on a rotor surface (hereinafter called "surface permanent magnet type motor"), a conventional method of reducing torque ripples is described as follows:
When the motor is not yet powered on, either a shape of a permanent magnet which is to be pasted on a surface of a rotor or a shape of a stator core is modified so that a waveform of an induced voltage which occurs at stator windings can be a sine wave when a rotor is rotated by some means from outside. Then, a driving current of a sine wave is applied to the windings, thereby reducing a torque ripple.
FIG. 1 is a block diagram depicting a controlling procedure of the torque ripple produced in a motor having interior permanent magnets used in the first exemplary embodiment of the present invention.
FIG. 2 is a block diagram depicting a controlling procedure of the torque ripple produced in a motor having interior permanent magnets used in the second exemplary embodiment of the present invention.
FIG. 3 is a block diagram depicting a controlling procedure of the torque ripple produced in a motor having interior permanent magnets used in the third exemplary embodiment of the present invention.
Exemplary embodiments of the present invention are described by referring to the attached drawings.
Exemplary Embodiment 1
FIG. 1 is a block diagram depicting a controlling procedure of the torque ripple produced in a motor having interior permanent magnets used in the first exemplary embodiment of the present invention.