GB391843A - Improvements in and relating to means for regulating the energy flow between two alternating current sources connected through a frequency converter set - Google Patents

Abstract

391,843. Motor generators; automatic regulation. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Hull, J. I.; 1338, Dean Street, Schenectady, New York, U.S.A.) Aug, 28, 1931, No. 24275. Convention date, Aug. 28, 1930. [Classes 35 and 38 (iv).] Induction machines.-Current transfer between two systems connected by a frequency-changing set is regulated by a generator cascaded with the asvnchronous machine of the set, the generator excitation being supplied by a transformer having two primary windings in opposition, one of which is fed in proportion to the primary current of the asynchronous machine. In the form shown, power may be transferred between systems 10 and 12, which are interlinked by synchronous and asynchronous machines 11, 14 respectively in either direction according to the position of the switch 34, and the amount transferred is regulated by the transformer secondary 36 which varies the voltage induced in the winding 40 of the transformer 31 provided with opposing primary windings 32, 33. The winding 40 feeds through a frequency changer 29 the exciting winding 27 of the exciter 21 for the regulating machine 17. The exciter 21 has an additional exciting winding 24 which minimizes fluctuations of the power transferred when a change of frequency occurs. The machines 14 and 29 have the same number of poles. By connecting the machine 21 direct to the machine 14, machine 17 may be omitted, or alternatively, a single machine with its slip rings connected to the transformer winding 40, and coupled to the main machine may be used in place of machines 17, 21, 29 ; this machine would have the same number of poles as the asynchronous machine 14, and would have rotary and stationary exciting windings to perform the functions of windings 27, 24 in the Figure. The Specification as open to inspection under Sect. 91 comprises also arrangements wherein the machine 14 may drive a load, such as a fan, and it is stated that the invention may be applied to the control of the current in any circuit; thus, instead of a machine 15 there may be in series with winding 32 any alternating-current circuit, the current of which is to be controlled. The transformer may be replaced by any equivalent voltage-producing means. This subject-matter does not appear in the Specification as accepted.