GB405234A - Improvements in or relating to regulating arrangements for electric generators - Google Patents

Abstract

405,234. Maintaining defined speeds of motors. LORENZ AKT.-GES., C., 1, Lorenzweg, Tempelhof, Berlin, and KUHLMANN, K., 11, Breite Strasse, Wallisellen, Zurich, Switzerland. April 16, 1932, No. 10984. Void [Abridged as open to inspection under Sect. 91 of the Acts, April 19, 1932]. [Class 38 (iii).] Fig. 6 shows apparatus for regulating the frequency of an asynchronous generator R, S, driven by a prime-mover P and supplying mains N. Q is a synchronous generator supplying current at constant frequency to a motor 20, the rotor of which is fed from the mains N. Any deviation of the mains frequency from the standard causes the armature to move to close either contacts 21, 22, or contacts 21, 23. Closure of contacts effects adjustment of the throttle of the prime mover P to give frequency control. To maintain constant the speed of the induction motor U driving the synchronous generator Q an eddy current brake E mounted on the shaft is fed from the D.C. mains 10 through a resistance F which is periodically short-circuited by means of a governor D, the period of short-circuit during each revolution being determined by the speed. This effects a fine regulation of speed. To obtain a coarse regulation a relay K is connected across the resistance F which alternately connects a motor 0 across opposite halves of a potentiometer L. When the period of open-circuit of the governor contacts exceeds the period of short-circuit or vice-versa the motor 0 operates to reset a resistance 19 connected to the armature of the motor U.