GB446690A - Improvements in or relating to dynamo-electric machines - Google Patents

Abstract

446,690. Controlling generators. CESKOMORAVSKA - KOLBEN - DANEK CO., Ltd., 36, PalackÚho, and KAUDERS, V., 19, PetrskÓ, both in Prague. Nov. 17, 1934, No. 33143. [Class 35] In a generator with the main field winding opposed by the armature field or by a series winding, one or both field windings have twc parallel branches on poles of opposite polarity, the distribution of current in the two branches is variable and leakage paths are provided separating the exciting and counteracting windings. In the form shown, adjustment of the rheostat 18 varies the relative strength of the poles the flux of which is opposed by the armature cross field and by the winding 23 connected in parallel with the main winding 9 on pole 5. The upper pole, which has the greater excitation is saturated and may have its cross section reduced by slots whilst the section of the yoke near the pole 5 may be increased. The yoke may have projections extending towards the pole tips to conduct the leakage flux and the field windings may be subdivided. The opposing field winding 23 may be omitted from crossfield machines, but in other machines the opposing windings are on the field poles and near to the armature and are well separated from the main field windings. The saturation may be varied by removing or adding plates to the yoke in the vicinity of the poles.