GB191415155A - Improvements in Controlling Arrangements for Direct Current Electric Motors. - Google Patents

Abstract

15,155. Soc. Anon. Dite S. T. A. R., (SystÞme de Traction Auto-Regulateur). July 21,1913, [Convention date]. Systems for continuouscurrent motors only.-In a system for the control of motors by connecting an auxiliary generator in series with the motors across the line, the voltage of the machine varies with the current through the system and the voltage across the motor terminals. In the arrangement shown, the auxiliary generator R is connected with the series motors M1, M2 between the main X and ground G. It is provided with a field coil P connected with an adjustable resistance r across the motor M1, and a series coil S the effect of which is opposed to the effect of the coil P. When the motors are to be started, the machine R is driven to run at its normal speed, and the end of the field coil P is disconnected from the point b in the main lead and connected to the point c in order to diminish the shock caused by the starting-current. The motor circuit is completed by closing the switch 1. The temporary connexion at the point c is broken and the connexion replaced at the point b. The first stage of starting may be obtained without reconnecting the coil P, thereby using only the series field coil S. For regenerative braking, the motor fields m1, m2, and the series coil S are reversed, and the field coil P is connected to the point c as for starting, so that it will be reversed also. To ensure the current in the coil P acting more quickly upon the system than that in the coils m1, m2, S, a choking-coil may be connected in series with the latter coils, or the coils m1, m2 may be shunted by auxiliary dynamos. Specifications 8108/12, 27,923/12, 7983/13, and 27,988/13 are referred to.