GB410842A - Improvements in and relating to electric supply systems - Google Patents

Abstract

410,842. Electric supply systems. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Arkenburgh, W. H. ; 1135, Parkwood Boulevard, Schenectady, New York, U.S.A.) Nov. 14, 1932, No. 32188. Convention date, Nov. 13, 1931. [Class 38 (iv).] Regulation, automatic systems for ; systems depending on the use of two or more sources ; equalizing load on generator.-Electrical energy is supplied to a variable load from two or more sources in parallel under the control of a saturable reactor having an alternating current winding connected to control the output of one supply circuit and a direct current saturating winding responsive to the current in another supply circuit. In one arrangement, Fig. 1, a main source 1 of any periodic potential with a direct current component is capable of supplying all the current required by a load 2 while maintaining also, through a rectifier 4, e.g. of the full wave copper oxide type, a substantially constant voltage across the terminals of a direct current auxiliary stand-by source 3 which is preferably, as shown, a storage battery, but may be a direct current generator, a primary battery or an alternating current and rectifier combination. The circuit of the load 2 includes a saturating winding 7 of a reactor 5 of which the variable reactance alternating current winding 6 is in circuit with the source 1. When the load requires little or no current the reactance of the winding 6 is preferably such that a very small charge is put into the battery 3, but when the load requires more current the winding 7 saturates the reactor 5, decreasing the reactance of the winding 6 and maintaining the voltage across the battery 3 substantially constant. The increased load current is thus taken from the source 1 and the battery 3 is maintained fully charged for service should the source 1 fail. When the source 3 is a direct current generator or a primary battery the voltages are so adjusted that no current is supplied to it under normal conditions. Fig. 2 shows a similar arrangement with a reactor 13 such that the direct current generator 12 supplies all the requirements of load 11 up to a predetermined value, whereafter the alternating current source 8 supplied any additional requirements. Up to the predetermined value of the load current the reactance of the winding 14 is high and little or no current is supplied by the source 8. With a higher load current the reactance of the winding 14 is reduced and more current is supplied by the source 8. In a modification of this arrangement the generator 12 is replaced by an alternating current source connected through a rectifier. Reference has been directed by the Comptroller to Specifications 13656/13, [Class 38 (ii)], 377,671, and 383,132.