GB949198A - An electric current converter with interphase transformer - Google Patents

Abstract

949,198. Converting. LICENTIA PATENTVERWALTUNGS-G.m.b.H. June 15, 1960 [June 15, 1959], No. 21013/60. Heading H2F. A current converter comprises two parallel partial converters interconnected by an interphase transformer whose windings are electrically separated, i.e. not parts of a tapped choke. As shown a converter comprises a three-phase transformer having a primary winding 1 and two secondary windings the ends of the first secondary winding being connected to the cathodes of rectifying elements 3a whose common anode connection forms the negative D.C. terminal, and the ends of the second secondary winding being connected to the anodes of elements 3b whose common cathode connection forms the positive terminal. The star point of the first secondary winding is connected to this positive terminal through a first winding of the interphase transformer and the star point of the second secondary winding is connected to the negative terminal through a second winding. The windings of the interphase transformer may be single turns passing through a cylindrical magnetic core which may be in two parts. A twelve-pulse embodiment in which the partial converters are polyphase bridge connections of rectifiers connected to star and delta secondary windings respectively is disclosed (Fig. 7, not shown). The rectifying elements may be semi-conductor elements, switch contacts or single anode Hg arc valves (not multi-anode valves). The connections may be altered to give a polyphase bridge fed by two parallel connected transformer secondary wingings (Fig. 3b, not shown).