Photovoltaic intelligent charging controller based on MPPT

SU Xiurong, WANG Zhengshi, MA Jinhong, PANG Jinyong
(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at solving problems of underutilization of photovoltaic panels and damage of batteries caused by misuse in offnetwork photovoltaic power generation systems, the photovoltaic panel output characteristics and battery charging and discharging characteristics were analyzed. A photovoltaic charging controller built on synchronous BUCK circuit was designed integrated with the most power point tracking(MPPT) technology and synchronous rectification technology, and an experimental prototype was set up. A paratactic threeloop PID control method with temperature compensation was applied to control the overall process of charging so as to realize intelligent switches between different charging ways such as constant current charging, constant voltage charging, MPPT charging and so on. The results indicate that, the controller uses the solar energy to the most while following the battery′s charging characteristics, by which the battery′s accidental damages are avoided, and the charging efficiency is improved up to 96% and the energy management is optimized eventually.
Key words: most power point tracking(MPPT); photovoltaic charging; battery; energy management