Illustration of SOC Controlled DC-DC Battery Charger

The presented paper focusses on the circuit design & analysis with data verified by simulation of a Modified Cascaded Buck-Boost DC-DC converter which incorporates a Break Switch, controlled based on State of Charge (SOC) for intelligent battery management. This topology uses a single Pulse Width Modulation (PWM) duty cycle to control both the converter stages which simplifies the complex control for step-up and step-down operations respectively. The most important contribution of this paper is the use of The Break Switch governed by SOC based logic, which enables the converter to smoothly divert power to DC loads or grid-connected systems by actively cutting the battery off from the charging path once it hits a predetermined threshold (80%). This feature prolongs the charger's useful life in post-charge situations, avoids overcharging, and improves battery longevity. The system employs an input voltage of 190 V and is integrated to a 48 V, 100 Ah Lead-Acid battery. The simulation results demonstrate the system's effectiveness in minimizing energy loss during conversion, thereby enhancing overall efficiency. The simulated results of the modified cascaded DC-DC converter are presented in this work.