This thesis aimed to study the structure of an on grid photovoltaic system and to get by the aspect of integration of such system to the power network. The integration method can have different topologies and is usually based on power electronic devices controlled by dedicated controllers. In order to transform the direct output signal of the PV panels to an alternative signal connected to the utility network, the Modular Multilevel Converter (MMC) was used in this study. The challenges linked to this type of converters are associated with its sub-modules balancing control, the ...