Light MMC motor driving system topology and modulation method thereof

Abstract

The invention discloses a light MMC motor driving system topology and a modulation method thereof, and belongs to the field of power electronic converters. The topology comprises a modular multilevel converter structure, a plurality of half-bridge and capacitor structures, a plurality of additional half-bridge structures, a plurality of three-winding high-frequency transformer structures and three-phase bridge arms; the half-bridge, the capacitor structure and the additional half-bridge structure form a novel sub-module; the three-winding high-frequency transformer structure enables all novel sub-modules to be interconnected together; each phase of bridge arm in the three phases of bridge arms is divided into an upper bridge arm and a lower bridge arm, each phase of upper bridge arm comprises n novel sub-modules and upper bridge arm inductors Larm1, Larm3 and Larm5, and each phase of lower bridge arm comprises n novel sub-modules and lower bridge arm inductors Larm2, Larm4 and Larm6; and a power coupling channel open-loop synchronous modulation method is adopted. According to the invention, sub-module capacitor voltage fluctuation in a motor operation full rotation speed range can be suppressed, and system common-mode voltage is reduced to a certain extent.

Description

technical field [0001] The invention relates to the technical field of power electronic converters, in particular to a light-duty MMC motor drive system topology and a modulation method thereof, which are used in medium-voltage motor drive systems. Background technique [0002] With the development of economy and society, medium-voltage high-power motors are widely used in fans, water pumps, railway traction and ship propulsion devices, etc., and the use of medium-voltage speed-adjustable drive systems can significantly save power, optimize control, and extend motor life. , to improve motor performance. Among them, the research hotspot of the medium-voltage variable-speed drive system is the multi-level converter technology. [0003] Among several multilevel converter topologies, MMC has attracted wide attention from all walks of life due to its advantages such as low harmonic distortion rate of output voltage waveform, common DC bus, easy expansion and redundant design, an...

AI Technical Summary

Problems solved by technology

The above solutions to improve the topology are all realized by closed-loop control of additional circuits, which require a large number of detection circuits and control computing resources

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