GB242002A - Electric relays for automatic voltage regulation - Google Patents

Abstract

242,002. Railing, A. H., and Angold, A. E. Aug. 5, 1924. Systems depending on two or more machines; regulation, automatic.-A device for switching a generator into circuit with an existing supply, when its voltage has been correctly adjusted, and for continuing the voltage regulation when the machine is running parallel, comprises two solenoids A, B controlled by the line and generator voltages respectively. The coils act in opposition and are arranged as shown in Fig. 1, or at opposite ends of a pivoted lever. Three contacts F1, F2, F3 at the end of the control lever are operated in turn to raise the machine voltage, to operate the parallelling switch, and to reduce the machine voltage if in excess. The upper contact F1 energizes one field in a reversible rheostat-controlling motor S to increase the machine voltage to the required value; at the instant the line core is overcome the contact F2 is made and the parallelling switch M, M1 is closed by means of the contactor T. A delay action is preferably incorporated, and should the difference in voltage be excessive the contact F3 is made before the switch M, M1 is closed and the paradlelling is deferred by the short circuiting of the contactor T until the voltage is reduced by the rheostat-controlling motor, which is reversed when either of the contacts F2 or F3 is made. When the switch M, M1 is closed the generator coil B only remains to control the rheostat, the line coil being cut out by an interlocked switch M2. By making the core of the line coil in two parts, which separate when the coil is de-energized, part of the weight opposing the generator coil is thereby relieved.