Abstract: Photovoltaic energy is considered one of the most promising energy sources due to its infinite power and has many advantages like longer life span, less maintenance, pollution free, simple installation, static and quick than the other alternative energy sources like wind, solar, ocean, biomass, geothermal, etc. In photovoltaic power generation system cascaded H-bridge multi level inverters play a vital role in power conversion. Diode clamped inverter, cascaded H-bridge inverter and flying capacitor inverter are the three widely used topologies of multilevel inverters. Among these three topologies, cascaded H-bridge multilevel inverter becomes a very attractive feature in the case of photovoltaic systems because solar cells can be assembled in a number of separate generators and each H-bridge cell will be available in a single module. This research study deals with harmonic analysis in 5, 7, 9 and 11 levels by considering upto 23rd harmonics of single phase cascaded H-bridge multilevel inverter employing multicarrier pulse width modulation technique for grid connected photovoltaic system. From this harmonic analysis, it is found that the total harmonic distortion in output voltage decrease and output voltage increase with increase in number of levels, reducing switching losses, reducing voltage stress and hence the efficiency of the system will be improved. The effect of cascaded H-bridge multilevel inverter topology and change in PV input parameters irradiation and temperature on the performance parameters has been analyzed and studied by the MATLAB/Simulink. The simulated output shows very favorable results. It can also be easily extended to more levels.
M.S. Sivagamasundari and P. Melba Mary, 2014. Analysis and Simulation of Single Phase Cascaded H-Bridge Multilevel Inverter Using Multicarrier PWM for Photovoltaic System. Research Journal of Applied Sciences, 9: 531-537.