GB948127A - Improved circuit arrangement for rectifier groups - Google Patents

Abstract

948,127. Converting. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. June 2, 1960 [June 18, 1959], No. 20988/59. Heading H2F. To avoid excessive voltage drop in a rectifying arrangement employing parallel connected multianode rectifiers which have reactions in the anode circuits to reduce fault currents, and hgh speed D.C. circuit breakers in the cathode circuits, the reactors of the corresponding anodes of pairs of rectifiers are electromagnetically coupled to reduce the voltage drop when normal load current flows and each circuit breaker controls the cathode currents of rectifiers whose anode currents are not magnetically coupled. Rectifier pairs such as 1, 1<SP>1</SP>; 1<SP>2</SP>, 1<SP>3</SP>, are connected in parallel between three-phase supply 3 and D.C. lines 2, 2. Each rectifier has anodes such as 8, 88; 81, 88<SP>1</SP> connected in pairs such as 8, 8<SP>1</SP>; 88, 88<SP>1</SP> through centre-tapped reactors 9, 17, to the respective phase of supply transformer 4. D.C. circuit breakers such as 55b are connected in the cathode circuits of rectifiers such as 11, 13 taken from different rectifier pairs. The voltages induced in the two halves of reactor 9, 11 cancel during normal operation, but not when one of the anodes backfires, particularly in the period between the opening of the D.C. circuit breakers and the A.C. breaker 6. A multianode backfire is also limited.