Author : Jaysing Ashok Kshirsagar and K. Vadirajacharya

Reformations in electricity sector along with various renewable energy promotion policies has increased the importance of small grid connected photovoltaic (PV) systems utilizing single-stage single-phase inverters. To improve the performance multilevel inverter are preferred over two levels. This paper proposes a single-stage five level inverter for grid connected (PV) system. The output current of the inverter can be adjusted according to the voltage of the photovoltaic (PV) array. This control scheme is based on SPWM topology. Schemes based on SPWM which do not require the service of a phase locked loop for interfacing the inverter to the grid are increasingly being employed for such applications. Performance evaluation of the five-level inverter is done on Matlab platform. The viability of the proposed scheme is confirmed by performing simulation and results validation.

Keywords: Five level inverter, Cascaded H-bridge inverter, SPWM, Solar PV array.