UNSYMMETRICAL CIRCUIT OF CASCADE FREQUENCY CONVERTER Russian patent published in 2021 - IPC H02M7/49 

FIELD: electrical engineering.

SUBSTANCE: present invention relates to the field of electrical engineering and power electronics, in particular to static multilevel electrical converters based on a cascade frequency converter, and can be used in high-voltage variable-frequency AC drives of high power with high quality of the synthesized voltage, as well as high reliability. The proposed schemes and algorithms make it possible to increase the number of levels of instantly synthesized line voltage, and, consequently, to improve its quality, and can also be used in emergency modes in case of failure of one of the phases of the classical scheme of a symmetric cascade frequency converter. The technical result is provided by the fact that one of the phases of the cascade frequency converter does not have electrical converters, and its output is connected to a common connection point of the remaining phases of the cascade frequency converter. In this case, the elementary cells of the remaining phases carry out the synthesis of line voltages.

EFFECT: invention simplifies the circuit of the cascade frequency converter, reduces the number of elementary cells and simplifies the control system. The positive effect is that the invention increases energy efficiency and energy conversion efficiency, improves the quality of the synthesized voltage and load current. The invention is characterized by the flexibility, modularity, simplicity and scalability of the proposed structure, the use of low-voltage elements in the electrical converter, a high degree of reliability and maintainability.

6 cl, 16 dwg