GB556132A - Improvements in or relating to electric generators for constant current systems - Google Patents

Abstract

556,132. Controlling dynamo-electric machines. LANCASHIRE DYNAMO & CRYPTO, Ltd., and STANSFIELD, W. April 22, 1942, No. 5387. [Class 35] [Also in Group XXXVII] The field winding 6 of a constant current generator 2 is energized in opposition by a constant voltage source 3 and a variable voltage exciter 4, which has two field windings, of which 11 is in series with the generator and 12 is connected across the terminals of the generator. The winding 6 may be in two parts separately connected to the constant voltage supply 3 and the variable voltage exciter 4. The generator field may also comprise a series winding 5 to compensate armature reaction. As shown, the system may consist of the generator exciters 3 and 4 and a motor 1 directly coupled together. Alternatively the exciter 3 may be replaced by any other constant voltage source. According to modifications, the winding 5 may be omitted, and replaced by a shunt winding of moderate ampere turns, and a shunt winding may be added to the exciter 4. Fig. 3 shows an arrangement in which two generators 21, 22 supply banks of constant current motors 18, 19 as described in Specification 556,133, either in series or separately from one or both of the generators. The double pole and triple pole double throw switches 20, 25, 26 are used to connect one or other or both of the generators to one or both of the banks in series. Linked double pole double throw switches 27, 28 connect the constant voltage exciters of the motors to the sources 23, 24. An alternative arrangement is illustrated in Fig. 4 (not shown).