Modular multilevel converters with integrated batteries energy storage

This paper presents the analysis of the modular multilevel converter with integrated batteries energy storage and highlights the influence of the power injected to the grid from the batteries or vice versa on the capacitors´ voltage balancing. The control objective of the converter is to maintain a balance between the arms. By redefining the circulating current in order to compensate for reactive power and rebalance the ac grid voltage asymmetries, it is shown through simulation results that the current injected by the batteries does not introduce any unbalance to the converter.