Cascaded two level inverter based grid connected photovoltaic system: Modelling and control

In this paper, isolated source cascaded two level inverter (CTLI) has been proposed for grid connected photovoltaic system. The system is operated to supply active power with available solar irradiance and to supply reactive power in absence of it. The conventional CTLI is controlled through vector control topology to provide controlled active and reactive power in the said conditions. The photovoltaic system is modelled and tested with the controlled grid connected CTLI, for solar irradiance variation, and reference reactive power variation in simulation environment. The control scheme has been introduced for dc link voltage of the dual level inverter. The dc link voltage is found to be maintained at required level for both type of power supply.