| 摘要 |
1,152,216. Inductor alternators. NATIONAL RESEARCH DEVELOPMENT CORP. 22 Sept., 1967 [28 Sept., 1966], No. 43435/66. Heading H2A. In an inductor alternator, flux-reversal instead of only flux-ripple, is achieved by placing a squirrel-cage winding in alternate rotor slots. The stator is D.C. excited by distributed conductors in the bottoms of the slots to produce two poles on either side of the neutral axis B-B<SP>1</SP>. This induces a similar pattern of currents in the rotor bars, and since these are in alternate slots, the intervening teeth are given alternate polarities, which induces flux-reversal in the stator teeth. The output A.C. winding is at the top of the slots. The region of the neutral axis B-B<SP>1</SP> is not thus polarized but acts as a " commutation " zone for the rotor currents and interpoles may be provided for this purpose. The machine may be made polyphase by increasing the number of slots to accommodate additional windings, the rotor bars being grouped in threes spaced by three empty slots (Fig. 3, not shown). The excitation of the machine may be increased by replacing the rotor bars by one or more turns a-d round individual teeth, as shown in Fig. 8. The machine may be of any polenumber, and stator and rotor may have different slot-numbers. " Commutation " of the rotor currents may be facilitated by grading the stator excitation winding in a sinusoidal manner (Fig. 13, not shown). |
