Control of a grid-connected cascaded h-bridge converter in photovoltaic application under asymmetric condition

Maintaining the stability of solar systems is among the most important technical issues in this field. Conventional control methods cannot maintain grid-connected photovoltaic system’s stability under unbalanced conditions in grid-connected inverters. This thesis proposes a novel control and modulation method for a new structure based on cascaded h-bridge converters for grid-connected photovoltaic systems under asymmetric operating conditions with reserve batteries. The partial shading is considered as an asymmetric condition in this work. In this method, the power losses and the number of switches are reduced and the output voltage levels are increased. The control method used to maintain the system’s stability and maximum power point tracking is the predictive control method which is so compatible with power electronic devices. The simulation and experimental results are proposed as well. This method can control the system in 50% partial shading condition.