  Electrical power conversions are common in a large variety of engineering
applications. With reference to AC/DC and DC/AC power conversions, a strong
research interest resides in multilevel converters, thanks to the many
advantages they provide over standard two-level converters. In this paper, we
first provide a power-oriented model of Modular Multilevel Converters (MMCs),
followed by a detailed harmonic analysis. The model is given in the form of a
block scheme that can be directly implemented in the Matlab/Simulink
environment. The performed harmonic analysis gives a deep and exact
understanding of the different terms affecting the evolution of the voltage
trajectories in the upper and lower arms of the converter. Next, we propose a
new model-based adaptive control scheme for MMCs. The proposed control allows
to determine the optimal average capacitor voltages reference in real-time,
thus allowing to properly track the desired load current while minimizing the
harmonic content in the generated load current itself.
