GB205114A - Improvements in and relating to rectifier installations - Google Patents

Abstract

205,114. Akt.-Ges. Brown, Boveri, et Cie. Oct. 9, 1922, [Convention date]. Void [Published under Sect. 91 of the Act]. Vapour apparatus, arrangements for; phase, changing.-In order to reduce upper harmonic currents in a vapour rectifier installation comprising a number of rectifiers fed from a common primary net-work, each rectifier or group of rectifiers is fed with currents which are out of phase with the currents feeding the other rectifiers or groups of rectifiers. In one arrangement two rectifiers are fed from six-phase secondary windings on a pair of transformers, the primary windings of one transformer being connected in star, and those of the other transformer in delta, to a three-phase net-work. In the arrangement shown, the rectifiers are divided into two groups with two rectifiers in each group, one group being fed from the six-phase secondary windings S<1>, S<2>, and the other group from the windings S<3>, S<4>. Phase differences of 30‹ are produced in the rectifiers of each group, while the two groups themselves are 15‹ out of phase, the phase differences being obtained by varying the arrangement of the primary windings as shown. The groups of rectifiers may be connected in parallel to a single direct-current net-work, or they may supply separate net-works, which may be at a distance from each other, e.g. in different sub-stations. The polyphase systems for feeding a number of rectifiers may be obtained in a single transformer, and the secondary terminals may be connected to the anodes of the various rectifiers without regard to symmetry in order to simply the wiring.