Multifunctional interleaved boost converter for PV systems

In this study, an interleaved boost converter cascaded with a battery charger buck converter is designed and implemented. The converter also has maximum power point tracking capability and the battery charge operation is designed for purpose of long life requirements of batteries. Proposed interleaved boost converter operates in conventional converter mode and in interleaved boost converter mode with different switching frequencies according to programmed power level to achieve maximum efficiency. A hybrid maximum power point tracking method is also introduced to provide obtainable maximum power from photovoltaic systems. If the batteries are not fully charged and the photovoltaic power more than the load power, charger starts to operate and charges the batteries. Batteries can be used as a backup power source when photovoltaic system power is incapable of supplying the load. Proposed system is controlled with a low cost PIC18F452 microcontroller. Simulation and experimental results show that the proposed interleaved converter structure has higher efficiency than other topologies and the proposed maximum power point tracking method provides fast and dynamic response.