GB245410A - Improvements in or relating to the compensation of asynchronous machines by shunt commutator machines connected in cascade - Google Patents

Abstract

245,410. Sachsenwerk Licht - und Kraft-Akt.-Ges. Dec. 30, 1924, [Convention date]. Alternating-current commutator and induction machines.-In a shunt commutator machine which is cascaded with an asynchronous machine for phase compensation, the exciting brushes are completely separated from and adjustable with regard to the brushes connected to the main windings. By these means, the necessity of displacing the exciting windings by ninety electrical degrees from the compensating winding is removed and the compensation and speed of the commutator machine may be controlled by moving the exciting brushes. In the form shown in Fig. 1, the brushes d of the exciting coils e bear on the same commutator as the main brushes c of the compensating coils b which are cascaded at a with the asynchronous machine. Further control of the compensation may be made by means of a choke coil or resistance f. In an alternative form, the excitation is provided by a separate winding preferably in the same slots as the main winding and brought out to a second commutator upon which the exciting brushes bear. By displacing the exciting brushes from the main brushes, a simplified arrangement of the coil heads may be obtained. An example is given of a machine with 3-phase 6-pole compensating and. commutating windings with the brushes displaced by 90‹ and the coil heads arranged in two planes, in place of the four planes which would be necessary if the brushes were collinear.