Modeling of Digital Controlled Battery Charger with CC and VC without Current Feedback

A constant current charging control method for charger is proposed in this paper. The basic idea is to maintain constant current charging by limiting the duty cycle of charger. Based upon the proposed constant current charging technique, a digital-controlled charger is designed and control method in software. The proposed digitalcontrolled charger has been applied to an on-line UPS prototype is shown in Fig.1. Additionally, when the battery voltage is increased to the preset voltage level using this technique, the charger changes the control mode to constant voltage charge. A digital-controlled charger is designed and implemented for uninterrupted power supply (UPS) applications. The charger control is based upon the proposed control method in software. Closed loop PI control is also provided to achieve the desired output voltage. The Simulation is done with the help of MATLAB Software using Simulink.