Improved method of diminishing the risk of back-ignition in series-connected electric rectifiers

摘要

182,462. Akt.-Ges. Brown, Boveri, et Cie. July 2, 1921, [Convention date]. Vapour apparatus, arrangements of. - In mercury-vapour rectifiers connected in series through transformer windings, the risk of backignition is diminished by magnetically interlinking the series-connected anode circuits. In the arrangement shown in Fig. 2, the rectifiers G1 G2, are supplied from the secondary windings S1, S2 of a three-phase transformer the direct-current net Ng being connected to the neutral point O1 of the winding S, and to the cathode of the rectifier G2. The anode currents of the same phase in each rectifier are interlinked inductively in pairs by the windings a - - f, as shown. In normal working, when corresponding currents are flowing simultaneously through both rectifiers, the currents in these windings act as choking-coils in respect of backignition or short-circuit currents occurring in one only of the rectifiers. In another arrangement, Fig. 3, each rectifier is supplied from a pair of secondary windings displaced in phase and having separate neutral points as shown. The various anode currents are linked together bv the windings a - - d of which a is inductively interlinked with c, and b with d. In another arrangement, Fig. 4, the secondary windings S1, S2 allotted to the rectifiers G1, G2 are similar and symmetrical polyphase systems and are shifted in phase as shown, adjacent phases in each rectifier, such as the phases 1, 1', being linked together by windings a, b, &c. This interlocking causes an overlapping of the anode currents in addition to the choking effect on backignition currents. The windings S1 S2 may be on two transformers, the primary windings of which are connected in series. The inter-linking in this arrangement may be made on six single-phase tranformers, or on a polyphase transformer with one limb unwound.