| 摘要 |
965,223. Paralleling A.C. machines; control of A.C. motors. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Jan. 13, 1961 [July 22, 1960; Sept. 6, 1960; Oct.14, 1960; Nov. 17, 1960], Nos. 25635/60, 30712/60, 35290/60 and 39535/60. Headings H2H and H2J. A synchronous polyphase machine 1 is accelerated to its synchronous speed by an auxiliary A.C. machine 5 which subsequently acts as an exciter through a rectifier 17 for the synchronous machine. The auxiliary machine may be an induction motor having a smaller pole number than the synchronous machine or may have the same pole number and be of the synchronous induction type. The synchronous machine may act as a condenser, motor or generator and be coupled to a load or prime mover 37, through a coupling, or in the case of a pumped storage scheme through a reversing gear 36. The auxiliary machine may also supply its own excitation through a rectifier 12. In another arrangement (Fig. 2, not shown), the stator A.C. windings of the two machines are connected in series for starting. In a further arrangement an auxiliary rectifier fed from the main supply is used during the synchronizing period to supply the synchronous machine. Where both machines have the same pole number they should be arranged for identical phasing of the rotors. The auxiliary machine may be used as a brake either dynamically or by plugging. Specification 869,243 is referred to. |
