GB545055A - Improvements in or relating to the excitation control of alternating current generators - Google Patents

Abstract

545,055. Exciting arrangements for alternators ; automatic control of voltage. IGRANIC ELECTRIC CO., Ltd. Dec. 13, 1940, No. 17659. Convention date, Dec. 14, 1939. [Classes 35 and 38 (iv)] In an exciting arrangement for an alternator 1 which is automatically connected to the load circuit L1, L2 by a switch 10, when its voltage approaches normal and wherein regulation is normally effected by a vibratory regulator 7 operating to short-circuit a resistance 6 in the field circuit of an exciter 4, provision is made for weakening the excitation during the run up so as to prevent the alternator voltage reaching a value sufficient to cause closure of the load switch 10 until the speed and therefore the frequency of the alternator has reached normal value. This may be done by including a resistance 8 in the field circuit of the exciter which resistance is cut out by a switch 9 when the voltage of the alternator approaches normal whereupon full excitation under control of the regulator 7 is established. Closure of switch 9 also completes the closing circuit for load switch 10. In a modification, the voltage responsive switch 9 is adapted, during the run up, to open the circuit through the normal regulating resistance 6 and to complete the field circuit of the exciter through a high resistance.