GB362150A - Improvements in and relating to apparatus for converting electrical power - Google Patents

Abstract

362,150. Converting; transformers. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Lennox, T. C. ; 24, Waverly Street, Pittsfield, Massachusetts, U.S.A.) Nov. 29, 1930, No. 36000. Convention date, Nov. 29, 1929. [Class 38 (ii).] In a polyphase rectifier installation in which the rectifier 13 is fed by a group of polyphase secondaries 16, 17 on a main transformer 12 the star points of the groups being interconnected by an interphase transformer 14 to which the negative side of the D.C. circuit 11 is connected, a condenser 19 dimensioned to carry the full load current of the transformer is associated with the interphase transformer in order to improve the voltage regulation of the installation over the whole or a substantial part of the load range. The condenser may be connected in shunt to a secondary winding on the transformer 14 as shown in Fig. 1, or across the primary winding extended to apply an increased voltage as shown in Fig. 3. The interphase transformer may be designed to saturate at a particular value of load current so as to produce resonance conditions in the condenser circuit and thus produce a sharp drop in D.C. voltage at that load current. In the case of a 12-anode rectifier, Fig. 4 (not shown), fed by four sets of polyphase secondaries, two interphase transformers having secondaries shunted by condensers are used for interconnecting the star points. In an alternative arrangement, Fig. 6, in which the rectifier is fed by a single polyphase secondary winding 33, a similar effect is obtained by connecting a condenser 35 and inductance 36 in parallel across a tertiary winding 34 provided on the main transformer.