Novel photovoltaic based battery charger including novel high efficiency step up DC/DC converter and novel high accurate fast maximum power point tracking controller
Abstract In this study, a novel photovoltaic based battery charger is designed and implemented. The key parts of the charger are a novel high efficiency step up DC/DC converter including only one switch and two diodes, and a novel maximum power point tracking controller. It is shown theoretically and experimentally that the sole switch and two diodes of the converter are turned on/off under zero current switching and/or zero voltage switching conditions, so there are no switching losses. The proposed maximum power point tracking technique concurrently uses photovoltaic voltage and current deviations to find the maximum power point. A prototype of the charger has been built, and experimental results are presented that explicitly validate theoretical results. It is experimentally verified that the contributions of this work are as follows: Firstly, the proposed step up DC/DC converter has the highest efficiency of 98.2% compared to the other step up DC/DC converter topologies reported in the literature. Secondly, the proposed maximum power point tracking controller provides the shortest convergence time along with the highest tracking efficiency compared to the other commonly used techniques. Furthermore, the converter and maximum power point tracking controller are two separate general purpose units, so they can be widely used in other systems.