三次元解析による誘導電動機のスキューの効果に関する検討

抄録

In the paper, I study some effects of the rotor skew in a 3-phase cage induction motor using 3-D finite element analysis. At first, the calculation method of the equivalent circuit parameters by the results of the analysis is proposed and variations of the parameters by rotor skew are calculated. The harmonic secondary copper loss, which is a part of the stray losses, is calculated at each skew ratio. The calculation method of the iron loss is proposed and the effects of rotor skew about the harmonic iron loss are clarified. The reduction of the magnetic vibration force by rotor skew is understood quantitatively by the analysis. The following results are obtained.
X₁ and X₂ which are T-type equivalent circuit parameters are increased and X_m is decreased by rotor skew. The harmonic secondary copper loss is reduced but harmonic iron loss is increased by rotor skew. The harmonic flux by the rotor slot pulsation are reduced by rotor skew in proportion to the skew coefficient but magnetic vibration force are not reduced in proportion to it, because the distribution of the flux density toward the axial direction is not uniformity by the axial direction flux made by the circular direction bar current, and many harmonic flux with different phase each other are overlapped at the air gap.