Li-ion battery charger based on digitally controlled phase-shifted full-bridge converter

This study is aimed to design and implement a battery charger for 40 series-connected Li-ion batteries. The batteries together set up a rated 144 V DC bus for the latter stage. To obtain higher power output capability and achieve higher conversion efficiency, a phase-shift full-bridge converter is adopted as the power stage of the charger. The operation modes and design considerations are carefully studied and depicted. This charger is controlled by a digital signal processor controller which is responsible for steering the circuit to fulfil constant-current constant-voltage charging profile, accompanied by the overcharging protection mechanism of Li-ion batteries.