GB769731A - Improvements in or relating to means for transforming the phases in electric power systems - Google Patents

Abstract

769,731. Phase changing. GENERAL ELECTRIC CO. Jan. 25, 1955 [Jan. 25, 1954], No. 2218/55. Class 38 (2). A nine-phase alternator 23 is connected to a three-phase distribution system 25a, 25b, 25c through three transformers 24, whereby the currents and voltage regulation are balanced. The input phases are divided into three symmetrical three-phase groups for connection respectively to the three primary windings 24a, 24b, 24c. Two of these windings, 24b, 24c, have windings directed into sections so coupled to the various star-connected secondary windings that the output voltages of these are displaced from the primary phase volts to the extent that they are in phase with the volts of the third transformer, in which the phase change which occurs is that resulting normally from the mesh-star winding arrangement. In a modification, in which one transformer only is used for voltage transformation, one input group is connected in reverse to the transformer primary winding through series reactors, and the other two groups are connected thereto through phaseshifting mesh-connected auto-transformers, Fig. 2 (not shown). The series reactors are designed to have the same impedance drop as the autotransformers.