A battery charger with maximum power point tracking function for low-power photovoltaic system applications

A battery charger with MPPT function for low-power PV system applications is presented in this study. For effective miniaturization, the battery charger is designed with high frequency operation. Some current-sensing techniques are studied, and their MPPT implementation is compared. A pulse charging method is also designed to prolong battery lifetime. The operation principles and design considerations of the proposed PV charger are analyzed and discussed in detail. A laboratory prototype is implemented and tested to verify the feasibility of the proposed scheme. Experimental results show that high MPPT accuracy and conversion efficiency can be simultaneously achieved under high frequency operation.