Novel Converter Topology With Reduced Cost, Size and Weight for High-Power Medium-Voltage Machine Drives: 3x3 Modular Multilevel Series Converter

The modular multilevel converter is considered the state-of-the-art power electronic solution for high-power high-voltage applications that require a DC stage and operate with fixed frequency at their AC terminals. However, in AC-AC variable-frequency applications, it has been proved this topology presents an unnecessarily large number of components intolerably high submodule-capacitor voltage ripple low frequencies. matrix was proposed as promising alternative medium-voltage electrical-machine drives since presented improved performance frequencies reduced comparison to resulting costs efficiency. Even though, one solutions stands out most machine drives, some operational drawbacks such unstable behavior under unbalanced grid conditions extremely complex internal control modulation. Recently, new named series presenting attractive characteristics frequencies, conditions, straightforward modulation, which are important advantages compared converter. Nonetheless, demonstrated paper, component count poor Thus, proposed, enhanced version preserves previously mentioned advantageous efficiency considerably other three topologies, cost, size weight.