GB628830A - Improvements in and relating to dynamo-electric machines - Google Patents

Abstract

628,830. Exciting dynamo-electric machines. HOLLYER, E. B., and METROPOLITANVICKERS ELECTRICAL CO., Ltd. Sept. 20, 1946, No. 28271. [Class 35] [Also in Group- XXXVII] An exciter for controlling two electrical quantities independently of one another in accordance respectively with separate controlling or input currents or voltages to the exciter, comprises a metadyne with adjacent brushes connected together externally of the armature through load elements which determine currents in respective pairs of brushes electrically in quadrature with one another for controlling the two quantities, the exciter exciting arrangement being such that on a departure of either controlled quantity from a reference value, a voltage is generated between the brushes producing the voltage which controls the other of said quantities. As shown, when the primary current of the main machine departs from a value corresponding to exciter excitation given by the winding 7, opposing winding 8 modifies the voltage at brushes a and b, d and c, and causing currents to flow in armature 1 and windings 5, 6 which by arma-, ture reaction adjusts the excitation of coils 34 on the main machine while similarly the excitation of coils 5, 6 on the main machine depends on a change of the resultant excitation of exciter coils 10, 11, which depends in turn on the secondary current of the main machine, i.e. that through resistance 12. Instead of the four coils 3-6 being all on a metadyne transformer, there may be two on each of a pair of motors having. their armatures in series, the purpose being to maintain identical voltages across the two armatures. In a modification, one end of each of four field coils on a metadyne transformer is connected to one brush on the exciter, the other ends of all the coils having a common terminal. Windings 7, 8 or 10, 11 may be replaced by a common winding. Specifications 628,827 and 628,831 are referred to.