Enhancing Solar Inverter Performance for both Stand-Alone and Grid Connected Systems

This paper presents a detailed performance analysis of multilevel inverter for both stand-alone and grid connected PV systems. Here, converter circuit is not only tested for parameters like total harmonic distortion (THD), power output and system efficiency by connecting the non-linear load but the variations of power factor is also considered which is not found commonly. First the simulated results for THD, power output and efficiency are tabulated with variation of load power factor individually for both systems and best operating power factor is found with respect to distortions and efficiency respectively. For Stand-alone system, circuit efficiency as high as 96.8% is achieved when operated at 0.85 power factor. Then the analytical analysis has been carried out for grid connected system where efficiency of 84.3% is achieved for 60^o grid phase angle and 75.8% for 10^o and thus proposing operation at higher grid phase angle. Harmonic components have been further reduced and brought below 5% level by means of passive filters. Finally, to validate the proposed outcome, simulated results have been compared with analytical results and corresponding plots have been shown.