GB407042A - Improvements in or relating to electrical converting arrangements comprising mercury arc rectifiers - Google Patents

Abstract

407,042. Converting; transformer systems. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, GARRARD, G. C., and RENNER, H. H., c /o General Electric Co., Witton, Birmingham. Aug. 31, 1932, No. 24312. [Classes 38 (ii) and 38 (iv).] Relates to the voltage regulation of a rectifier 1 and consists in connecting the secondary windings 6, 7, 8 of auxiliary transformers 9, 10, 11 in the supply leads to the primary of the main transformer 2 so as to inject a bucking voltage dependent on the load. The core of each auxiliary transformer is provided with an additional limb II which forms a shunt path between the primary and secondary windings. Mounted on this limb are voltage coils 20, 21, 22 connected across the load circuit 18, 19, and current coils 15, 16, 17 connected in series with the load circuit. At no load the voltage coils saturate the limbs II so that the bucking effect is largest. As load increases the saturation is reduced, the current coils acting in opposition to the voltage coils, to reduce the bucking effect. In a modification of this no shunt path or voltage coil is provided and the current coil is arranged on the same limb as the secondary winding. As the load increases the voltage buck is reduced by saturation of the core increasing. To prevent too large a magnetising current flowing when the core is saturated, chokes are connected in the supply. leads to the primary windings. In a further modification, to avoid unbalance, the shunt limb is divided longitudinally and the control winding is arranged on the two parts to produce fluxes in opposite directions so that the limb has the same reluctance in each direction. In another modification, to avoid unbalance, part of the primary and part of the secondary are arranged on each of the outer limbs of a three limbed core, the centre limb carrying the control winding. A further arrangement is described for use with a main transformer having a mesh connected primary.