| 摘要 |
PCT No. PCT/SE91/00293 Sec. 371 Date Dec. 16, 1992 Sec. 102(e) Date Dec. 16, 1992 PCT Filed Apr. 24, 1991 PCT Pub. No. WO91/16754 PCT Pub. Date Oct. 31, 1991.A synchronous machine having a stator and a rotor, of which one, preferably the stator, is provided with a three-phase, symmetrical, Y-connected armature winding intended to have a sinusoidal line voltage or a sine-wave supply current, whereas the other, preferably the rotor, carries a field magnet system. The magnetic flux generated in the air gap between the ferromagnetic cores of the stator and the rotor and linked with the armature winding has a density whose mean value, as determined over the axial extension of the air gap, varies along the air gap in its circumferential extension in accordance with a uniform periodic function whose positive and negative half-periods are mirror images of one another and whose period coincides with the extension of two pole pitches of the field magnet system, and whose shape deviates from a purely sinusoidal shape. Within one-half of one positive half-period of the function f( alpha , beta )=1 for 0</= alpha </= pi /2 and f( alpha , beta )=cos( alpha - beta )-sin beta /1-sin beta for beta < alpha </= pi /2, where alpha is the angle in the circumferential direction of the air gap and varies from 0 DEG to 90 DEG electrical over half of one-half period and beta is a constant not greater than about 40 DEG electrical.
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