50-Hz THREE-PHASE-TO-60-Hz SINGLE-PHASE VOLTAGE CONVERTER Russian patent published in 1994 - IPC

FIELD: current conversion. SUBSTANCE: converter has two transformers with a three-phase primary winding and six-phase secondary winding connected in two inverse in two stars, and a unit consisting of twelve fully controlled switches with bilateral conductivity. The primary winding of one transformer is star-connected, and that of the other is delta-connected. A twelve-phase symmetrical system of voltage is formed on the secondary side of both transformers. Each switch is connected to the lead of one phase of the secondary windings. Connected to the converter output are common point of the switches and the common neutral conductor of the secondary windings. Each switch carries the voltage of one phase of the twelve-phase system to the converter output during a half cycle of the 60-Hz frequency. Each pair of switches is changed over at the instant when the voltage applied to the output approximately equals the voltage of the adjacent leading phase in instantaneous values. EFFECT: obtaining of output voltage close to the sinusoidal one with a low content of high harmonics. 2 cl, 2 dwg