Effect of Irradiance on THD of Neutral Point Clamped Inverter Fed from PV Cell

The multilevel inverter works with the principle of simple inverter which inverts DC to AC with low harmonics. The output current and voltage may be generated of any required frequency with suitable control and efficient switching. This work represents about the three-level and five-level of NPC multilevel inverters utilized for DC to AC control transformation. DC source can be availed from conventional batteries, but PV solar cell may reduce dependency of the inverter for performing the basic transformation of signals as solar energy is largely available and can be smoothly harnessed with the use of suitable converter topologies. Here both three-level and five-level NPC inverters used for DC to AC power transformation are analyzed and compared on the basis of all the parameters performed in MATLAB/SIMULINK platform. There are several modulation techniques available. Here SPWM modulation technique has been used for generation of efficient results. As photo voltaic cells are widely used for several applications for the ease of operations, same is being used for replacement of conventional DC sources. PV cell parameters have been mentioned below for smooth understanding of the comparison. THD analysis of current of inverters without PV cell and with PV cell has been found to be quite nominal and within the limits. The effect of the irradiance is studied and compared in case of both inverters. Finally, the effect of different level of irradiance on THD of neutral point clamped inverter output current for RL load is presented.