Control of a DC/DC Converter attached to an Asymmetric Multilevel Inverter for Solar Energy Injection to Microgrids

This paper is based mainly on selecting a DC-DC converter that allows the proper operation of the cascaded 27-level asymmetric multilevel inverter that injects photovoltaic energy into a microgrid. The work consists mainly on designing, building and controlling the DC/DC converter appropriate for this topology. The topology of the asymmetric multilevel converter requires independent and in the 9:3:1 ratio DC voltages, adding to this the control for the extraction of the maximum power of the photovoltaic panels. Only the low power cell is addressed in this paper and a string photovoltaic configuration is used. The system is validated using simulations and incorporating experimental results for the buck converter in cascade with the non-inverting buck boost converter with resistive load and a battery as extracted energy storage from a photovoltaic string.