| 摘要 |
PURPOSE:To improve the building factor of iron loss of the central leg of a three-phase transformer iron core, by forming the central leg by laminating electrical sheets provided with minute distortion in the direction perpendicular to the rolling direction. CONSTITUTION:Electrical sheets cut into given shapes are laminated to form outer legs 1, 2, upper yoeks 4, 5 and lower yokes 6, 7. Electrical sheets provided with linear minute distortion 12 in the direction perpendicular to the magnetizing direction are laminated to form a central leg 11. Thereby, not only the eddy- current loss due to fundamental wave magnetic flux can be reduced, but also the eddy-current loss due to the higher harmonic component of the distorted wave magnetic flux can be reduced. Moreover, since, owing to the linear minute distorsion, the magnetic permeability in the rolling direction decreases by about 25%, there is a decrease in amount of magnetic flux flowing in the central leg 11 in the state where it is not excited, so that the distortion of the magnetic flux waveform is eased. As a result, the building factor of the iron loss of the central leg is improved. |
