Unbalanced power control of a modular multilevel converter with photovoltaic resources and the capacitor voltage ripple analysis

The modular multilevel photovoltaic (PV) converter can achieve independent power control and help to increase the efficiency of system. However, output among PV modules is unbalanced, which will result in loss system if not properly controlled. This paper first introduces a scheme adjust distribution dc grid, ac grid modules, presents mathematical bases unbalanced strategy. voltage ripple MMC sub module (SM) capacitor also an important parameter. In this system, SM has been analysed relevant articles. Because there are many variables, it easy analyse. Here, law analysed, by simplifying variables presenting fast analytical method, reference significance for selection capacitor. Matlab simulation hardware loop experiment built StarSim Modelling Tech verify effectiveness introduced strategy correctness analysis.