GB310887A - - Google Patents

Abstract

310,887. Siemens - Schuckertwerke Akt.-Ges. May 2, 1928, [Convention date]. Void [Published under Sect. 91 of the Acts]. Alternating-current commutator and induction machines; commutating windings; exciting.- The commutating pole or compensating windings of a continuous or alternating-current working on a circuit of constant resistance are energized by the potential across the constant resistance circuit or by the energizing potential of the commutator machine whereby the use of large conductors carrying line currents is avoided. Fig. 1 shows the invention applied to a commutator machine 2 cascaded with an asynchronous wattless output machine 1. The compensating winding 4 is in series with the armature winding in the usual way, but the commutating pole windings 3 are star-connected in parallel with the secondary circuit of the main machine 1. Fig. 2 shows a rotor excited commutator machine cascaded with a wattless output machine 1. The compensating winding 7 in this case is connected in parallel with the secondary circuit of the main machine. The winding 7 may be so dimensioned and adjusted in phase that its current has a. component which produces the energizing field of the machine whereby the regulating transformer 6 is relieved of part of the exciting current. The resistance 8 serves for the regulation of the compensating action. The invention is also applicable to commutating machines connected in the secondary circuit of asynchronous machines having outputs independent of slip. In this case, the commutator machine introduces into the secondary of the main machine two potentials one of which increases proportionately to the slip while the second is independent of the slip. This second potential works on a circuit of constant resistance and may energize the commutating pole windings. If, as in the case of the energizing windings of synchronous machines or asynchronous wattless output machines, the resistance varies with temperature, a correspondingly variable resistance may be connected in the circuit of the commutating pole or compensating windings. Commutating pole or compensating windings may be connected partly in series and partly in shunt.