GB306529A - Improvements relating to the regulation of the starting potential of electrical machines connected up through booster transformers - Google Patents

Abstract

306,529. Siemens - Schuckertwerke Akt.-Ges. Feb. 23, 1928, [Convention date]. Systems depending on static transformers.-In systems in which an alternating-current machine such as a rotary converter 1 or a synchronous motor with starting cage windings is supplied through a boosting transformer 3 , means mechanically controlled by the main switch 4, on the switch 4 being opened automatically or by hand, cause the transformer 3 to be brought into the starting position in which the machine will receive the minimum voltage favourable for starting. The transformer 3 may have one coil rotatable and is controlled by a reversible motor 6 energized from a separate supply 10. If the transformer 3 is not in its starting position when the switch 4 is opened, the motor 6 is energized through the trailing switch 7 connected to the transformer 3 and through the switch 41 connected to the switch 4. To regulate the starting potential, the transformer 3 can be adjusted in one direction or the other, prior to closure of the switch , by depressing one or the other of two control keys 11, 12. Limit switches 8, 9 automatically switch out the motor 6 when the transformer 3 has reached an end position. After the machine has started, the booster transformer is adjusted to raise the voltage. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a booster comprising a " tapping " transformer. This subjectmatter does not appear in the Specification as accepted.