Open AccessControllers for eliminating the ac components in the circulating current of modular multilevel converters
Author(s) -
Darus Rosheila,
Pou Josep,
Konstantinou Georgios,
Ceballos Salvador,
Agelidis Vassilios Georgios
Publication year - 2016
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2014.0930
Subject(s) - modular design , converters , harmonics , harmonic , capacitor , control theory (sociology) , current (fluid) , power (physics) , voltage , three phase , computer science , harmonic analysis , electronic engineering , engineering , control (management) , electrical engineering , physics , acoustics , artificial intelligence , operating system , quantum mechanics
Control of the circulating currents in a modular multilevel converter (MMC) is an integral part of its operation as the circulating currents have a significant impact on the rating of the power devices, losses and also capacitor voltage ripples. This study proposes two methods to control the circulating currents in the phase‐legs of the MMC to their minimum dc value through elimination of the low‐order harmonic components in the circulating current. The first method acts directly on the ac harmonics of the circulating current allowing the dc component to establish naturally, whereas the second one directly controls the current to its dc reference. Simulations and experimental results from a laboratory prototype demonstrate the operating principles of the two methods and validate their performance.