CONVERTER UNIT WITH PARALLELLY INCLUDED MULTISTAGE SEMICONDUCTOR CONVERTERS AND THEIR CONTROL METHOD Russian patent published in 2017 - IPC H02M1/12 H02M7/483 H02J3/38 

FIELD: electricity.

SUBSTANCE: method of controlling several multistage semiconductor converters (2) parallelly connected with their contact AC voltage outputs (21) is performed. The converters contain each sequential circuit of two-pole submodules. Each of the submodules comprises of at least two controllable electronic switches and a power storage device, while the controlled electronic switches are connected in series to form a sequential circuit. The sequential circuit is located parallel to the power storage device. In the method, a step voltage is created in the corresponding AC voltage contact output (21) of the multistage semiconductor converters (2). In this case, the voltage change of the second multistage semiconductor converter is shifted in time with respect to the voltage change of the first multistage semiconductor converter. The converter unit (1) comprises of means for delaying in time the change of the AC voltage of the at least one multistage semiconductor converter (2) with respect to the change in the AC voltage of the other multistage semiconductor converter (2).

EFFECT: decreased proportion of the upper harmonics of the output AC voltage.

13 cl, 6 dwg