Pole-to-pole asymmetry in interior permanent magnet machines with arc-shaped slots

摘要

An interior permanent magnet machine includes a rotor formed with a plurality of slots that are substantially arc-shaped and referred to herein as arc segments. A first layer of arc segments are disposed in a first pole. The first layer defines a first configuration relative to a first arc center. A second layer of arc segments are disposed in a second pole. The second layer defines a second configuration relative to a second arc center. The rotor is configured such that the first configuration is different from the second configuration, thereby exhibiting pole-to-pole asymmetry. The first configuration is sufficiently different from the second configuration such that torque ripple may be minimized. In one embodiment, the first layer includes first, second and third arc segments. The rotor may be configured such that the second arc segment is radially offset relative to the first and third arc segments.

主权项

1. An interior permanent magnet machine comprising:
a rotor having a plurality of arc segments that are substantially arc-shaped; wherein the rotor includes a first and a second pole; wherein the plurality of arc segments includes a first layer disposed in the first pole, the first layer defining a first configuration relative to a first arc center; wherein the plurality of arc segments includes a second layer disposed in the second pole, the second layer defining a second configuration relative to a second arc center; wherein the rotor is configured such that the first configuration is sufficiently different from the second configuration to minimize torque ripple; the first layer includes first, second and third arc segments in the first pole, the second arc segment being adjacent to the first and third arc segments; the first and third arc segments are located at a first distance from the first arc center, the first and third arc segments being symmetric relative to a first pole axis; the second arc segment is located at a second distance from the first arc center; and the first distance is different from the second distance.