Performance of single stage cascaded H-bridge multilevel converter based grid interfaced PV system

Abstract

Large scale grid connection of PV (Photovoltaic) systems provides a wide range of growth in non-conventional energy and for this, the cascaded based multilevel converter plays a significant role. This has its advantages in not only providing a simplified structure when compared to other converters but also by adjoining multiple single phase converter modules. It also increases the voltage levels. In present paper, the proposed configuration incorporates single phase single stage SPV (Solar Photovoltaic) system. This provides harmonics elimination in addition to feeding of SPV energy into the grid at a power factor of unity. The role of MPPT (Maximum Power Point Tracking) is for balancing the grid abnormality or disparities and to track the reference PV voltage. The decoupled control with sinusoidal PWM (Pulse Width Modulation) is incorporated in the present illustrations for enhancing system's performance. An analysis is also carried out for dynamic changes in insolation as well as abnormal conditions which includes swell of voltage. Multiple simulations are further carried out for validating dynamic and non-ideal characteristics to bring in dependable sustainability of the system with power factor correction. As discussed, the aforementioned issues are mitigated keeping THD (Total Harmonic Distortion) values of the grid current well within the prescribed range of IEEE-519 standard.