GB391767A - Improvements in and relating to electric transmission systems - Google Patents

Abstract

391,767. Electric systems for transmitting mechanical power; dynamoelectric machines. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Soc. Generale de Constructions Electriques et Mecaniques Alsthom ; 146, Avenue des Champs Elysees, Paris.) July 31, 1931, No. 21910. Convention date, Aug. 2, 1930. Void [Published under Sect. 91 of the Acts]. [Classes 35 and 38 (iv).] Exciting.-The external characteristic of the dynamo-electric generator 7 of a power transmission system for vehicles, for example, is approximated to that of the prime mover 6 driving it, i.e. to a hyperbola, by excitation arrangements comprising a field 8 energized by a constant but adjustable source of potential, such as the battery 9, in series with an exciter 10 energized by the constant source and by the current of the generator in opposition. The constant potential source may be in series with a second exciter 25 energized in a similar manner to the first exciter. In a modification, the constant source 9 energizes the two exciters only, in opposition to their energization by the generator current. One or both exciters may have an excitation 37 in shunt with the generator assisting the constant potential excitation. The two exciters may be combined in one machine, for example by two independent magnetic circuits operating upon a single armature. The exciters may be independently driven by constant speed motors or from the shaft of the main generator. The generator or an exciter may have a series winding to allow for starting by means of the battery.