Improvements relating to the indication and/or control of the stability of synchronous dynamo-electric machines

摘要

646,255. Automatic control systems for alternators. GRAY, A. H., FENWICK, D. R., and METROPOLITAN - VICKERS ELEC. TRICAL CO., Ltd. July 27, 1948, Nos. 20029 and 24008. [Class 38 (iv)] [Also in Group XXXVI] The power taken from a generator 9 is applied to a wattmeter 4 which is combined with an ammeter 6 fed with the exciting current so that the pointer 15 measures the ratio of output power to exciting current; on approaching the value of this ratio which corresponds to instability, the pointer 15 preferably closes contacts 14, 13 to actuate a relay 16 to close contacts to energize a motor 17 which adjusts rheostat 18 to vary the input to a circuit 19 controlling the exciting current. Motor 17 may also adjust rheostat 21 to alter the sensibility of ammeter 6 and thus prevent hunting.