MULTILEVEL FREQUENCY CONVERTER WITH DIFFERENTIAL VOLTAGE LEVELS AND BYPASS SEMICONDUCTOR KEYS Russian patent published in 2014 - IPC H02M7/527 H02M7/483 H02M7/53862 H02P27/08 

FIELD: electricity.

SUBSTANCE: invention pertains to electrical engineering and can be used in high voltage regulated electrical drives. Multilevel frequency converter with differential voltage levels and bypass semiconductor keys contains input multi-winding transformer, control system and several levels of power cells in each phase. Output voltage of cells for each level is different: output voltage of the first level cells is equal to half of the rated output voltage of frequency converter and each next level is twice less than voltage of the previous level. In parallel to output of each power cell there's bypass semiconductor key, one semiconductor key of power cell is connected to the first control output of the control system by commutator switch in case of the cell failure, while its other control input is connected to the second control output of the control system by commutator switch in operating modes to change output voltage of the frequency converter.

EFFECT: obtaining a larger number of voltage levels at output of the frequency converter with less number of secondary windings of input multiphase transformer and with less number of power cells, providing possibility of control for bypass keys position not only in case of failure.

3 dwg