Fuzzy-controlled Li-ion battery charge system with active stale-of-charge controller

A fuzzy-controlled active state-of-charge controller (FC-ASCC) for improvin g the charging behavior of a lithium-ion (Li-ion) battery is proposed. The proposed FC-ASCC is designed to replace the general constant-voltage chargi ng mode by two kinds of modes: sense and charge. A fuzzy-controlled algorit hm is built with the predicted charger performance to program the charging trajectory faster and to remain the charge operation in a proposed safe-cha rge area (SCA), A modeling work is conducted for analyzing and describing t he Li-ion battery in charging process. A three-dimensional Y-mesh diagram f or describing the charging trajectories of the proposed FC charger is simul ated. A prototype of a Li-ion battery charger with FC-ASCC is simulated and realized to assess the predicted charging performance. Experiment shows th at the charging speed of the proposed FC charger compared with the general one increases about 23% and the charger can safely work in the SCA.