Realization of Cascaded H-Bridge Multilevel Inverter Based Grid Integrated Solar Energy System With Band Stop Generalized Integral Control

The high power grid integrated solar energy system (GISES) prefers multilevel inverters for reduced switching losses and lower harmonics in the injected current. The integration of solar PV array with multilevel inverters (MIs) requires a proper selection of multioutput dc-dc converters. Moreover, the performance of two-stage GISES with isolated multioutput dc-dc converters and dc-ac multilevel inverters are less investigated in the literature. In this article, a cascaded H-bridge multilevel inverter with isolated multiple-output zeta converter is used. It exhibits reduced switching stresses and improved efficiency, concerning to multiple dc-dc converters fed MI. The maximum power point tracking method, based on the firefly algorithm, is implemented on the isolated multiple output zeta converter to ensure maximum power extraction at adverse irradiation conditions. The power quality improvement and active power exchange through a band stop generalized integral control, and the grid synchronization is achieved through an enhanced phase-locked loop method. The proposed system is designed and simulated in MATLAB/Simulink, and the results validate the theoretical claims. The performance of the GISES is verified using an experimental prototype developed with the help of a dSPACE Micro Lab Box and a solar PV simulator.