GB434451A - Improvements in and relating to dynamo electric machines - Google Patents

Abstract

434,451. Controlling induction machines. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. July 12, 1934, No. 20483. Convention date, July 12, 1933. [Class 35] An induction motor is given an increased pole number by energizing it with single phase current supplied at terminals different from those used when the machine operates with three phase current. In the form shown in Fig. 4, the machine operates with four poles when a three phase supply is connected to the delta points and with six poles when single phase current is supplied at the terminals indicated, the phase winding halves then being all in parallel. In a modified form, the phase winding halves are all in series, half of them being reversed for six poles or connected all in the same sense for twelve poles. In the form shown in Fig. 5, three phase connection to the star points gives four poles while single phase current at the points indicated yields six. Other pole numbers may be obtained by using known pole-change methods in addition.