GB196586A - Improvements in or relating to synchronized asynchronous machines - Google Patents

Abstract

196,586. Compagnie GÚnÚrale Electrique. April 22, 1922, [Convention date]. Motors, controlling; exciting.-A synchronous induction machine is constructed with the stator as field magnet and the rotor as armature and is provided with a continuous-current commutator winding on the rotor in addition to the polyphase minding, the stator winding being of the star three-phase type, two of the phases being excited from the continuous-current winding at synchronous speed, while the third is short-circuited for damping; the commutator brushes are set back 60‹ from the neutral line at no load. The continuous-current winding C, Fig. 4, is connected in series with the stator phase winding 3. The machine is started up by gradually diminishing the resistances r<1>, r<2>, r<3>, and when these have been eliminated the short-circuit across the phasewindings 1 and 2 is replaced by a short-circuit across the phase-winding 1, Fig. 6. The phasewindings 2, 3 are thus left in series with the continuous-current winding and the winding 1 acts as a damping winding. If it is desired to reverse the direction of rotation of the machine, the winding C is connected to the phase-winding 1, and for synchronous running the phase-winding 3 is short-circuited and the two windings 1 and 2 connected in series with the winding C. The resulting flux is thus shifted 120‹ so that no movement of the brushes on the commutator C is necessary. The starting of the machine may be controlled by a three-armed switch.