GB129828A - Improvements in or relating to the Control of Dynamo Electric Machinery. - Google Patents

Abstract

129,828. Wilson, J. C. July 29, 1918. Exciting.-To minimize the lag or delay in regulation due to the self-induction of the fieldmagnet circuit of dynamo-electric machines, an additional winding a<x>, Fig. 1, is arranged on the field-magnet system of the main machine a and is connected in circuit with an additional winding d<2> on the exciter d, the windings a<x>, d<2> being connected also to a constant-potential source l. When the current flowing through the main field winding a<1> of the machine a is being increased by a manipulation of a regulating-resistance b in the circuit of the exciter main field winding d<1>, an electromotive force is induced in the current containing the coils a<x>, d<2> by transformer action of the winding a<1> on the winding a<x>, and the consequent alteration of the current through the winding d<2> has the effect of causing the exciter d to increase its voltage, producing an increased current in the winding a<1>. Similarly, decrease of current in the winding a<1> causes an automatic further decrease of voltage in the exciter d. In a modification, Fig. 2, the main machine a has one field-magnet winding a<x> connected to a source of exciting-current in series with an auxiliary machine f which may oppose or assist the voltage of the source l by suitable adjustment of the field regulator b ; additional windings a<1>, f<2> on the main and auxiliary machines are also connected together and to the source l. The invention is applicable to dynamo-electric machines employed in the driving of rolling-mills.