Single-phase cascaded H-bridge multilevel inverter with nonactive power compensation for grid-connected photovoltaic generators

This paper presents a single-phase cascaded H-bridge multilevel inverter for a grid-connected photovoltaic (PV) system with nonactive power compensation. A generalized nonactive power theory is applied to generate the nonactive current reference. Within the inverter's capability, nonactive power required by the local load is provided to improve the grid power quality. To minimize harmonics and achieve zero error tracking, a hybrid controller composed of a proportional controller and a repetitive controller is applied to current control. A single-phase 11-level cascaded multilevel inverter is considered in both simulation and experimental tests. Each H-bridge is connected to a 195 W solar panel. Simulation and experimental results are presented to validate the proposed ideas.