METHOD FOR ALTERNATE CONTROL OF THREE-PHASE FREQUENCY CONVERTER Russian patent published in 2020 - IPC H02M5/44 

FIELD: electrical engineering.

SUBSTANCE: invention relates to the electrical equipment. Invention comprises in each of three phases in-series connected N rectifier-inverter units 1–9, each of which is connected by input to windings of transformers 10–18 with different connection group and which are controlled in turn depending on value of required value of output voltage, in which in this range from zero to 1/N, pulse-width modulation (PWM) of one unit of 1–9 in phase, in range up to 2/N – of another unit, etc., while others are in limit mode (+1, -1, or 0), which is achieved due to nonlinearity units 24.

EFFECT: novelty is that in each of three phases by output in PWM mode there are units with different group of connection of transformer supply windings so that phase shift between adjacent ones makes 60/N electric degrees.

1 cl, 2 dwg