GB446518A - Improvements relating to the control of electric generators - Google Patents

Abstract

446,518. Self - - contained supply systems; automatic control of speed. STONE & CO., Ltd., J., Deptford, and NIXON, L. R., 54, Sidewood Road, New Eltham, both in London. Oct. 30, 1934, Nos. 31'090 and 36277. [Class 38 (iv)] The field circuit of a variable speed generator 1 in a railway train installation is excited at a definite speed of the generator by a relay 12 energized by a small auxiliary generator 6 driven with the main generator so as precisely to vary in speed therewith. The auxiliary generator is preferably an inductor alternator but it may be a D.C. machine. Excitation may be provided by a permanent magnet or it may be self-excited through a rectifier for example, or, excited from a separate source. The inductor alternator may be connected through a rectifier 15 to a relay which closes the circuit of the exciting winding of an automatic voltage regulator 29 in addition to the circuit of the field winding 14 of the main generator. To maintain polarity of the main generator the main circuit includes contactor switches 16, 17 such as described in Specification 424,127, [Group XXXVII], for example, energized through reversely connected rectifiers 23 and preferably also interlock contacts. The speed at which the relay operates may be adjusted by resistance in series with its winding. According to second Provisional Specification the auxiliary generator may be employed in keeping constant the speed of a shaft driven from a variable speed driving shaft or in controlling the speed of an electric motor, the excitation of any speed-sensitive control means being obtained from an auxiliary generator driven from or with the electrical apparatus controlled.