GB190911339A - Improvements in and relating to Electric Systems for Power Transmission. - Google Patents

Abstract

11,339. Alleremeine Elektricitõts-Ges. May 13, 1903, [Convention date]. Dynamos and motors combined for transmitting power.-In an electric power-transmission system, the speed of the working motor is rendered independent of the current by providing the starting- generator with an auxiliary field winding, energized by an exciter with a field coil shunted across a resistance in the main circuit. The exciter 7 supplies the fields 3, 6 of the motor 1 and the starting-generator 4 respectively. The exciting- circuit includes a switch 10 for controlling the working motor 1. The auxiliary field 12 of the generator 4 is connected to a machine 11, shown on the same shaft as the generator 4, but which may be separately driven, and which has a field coil 13 connected in parallel with the resistance 14. A resistance 15 is connected in the circuit of the field coil 12, and is regulated by the controller 10. As the motor current increases, the excitation of the auxiliary machine 11 increases, thereby increasing the current through the field coil 12 and raising the voltage of the generator 4. The resistance 15 may be connected in circuit with the field 13. During retardation, the motor 1 acts as a generator, and the electro-motive force of the auxiliary machine 11 reverses, so that the current in the coil 12 weakens the field of the starting- generator. When the latter machine is reversed by the controller, the current in the field coil 12 is also reversed.