Closed Loop Control of Bidirectional Buck-Boost Converter for Battery Management in Automotive Systems

Abstract

A new control logic is constructed for bidirectional buck-boost converter (BBC) through mathematical modeling and implemented in Simulink. The BBC bridges 12 V and 24 V in dual battery automotive systems to meet the power load requirements of advanced automotive electronics. From mathematical modeling, gains of proportional, integral, derivative with filter (PIDN) control law are obtained. Mode selection circuit is developed for Buck and Boost mode control. For each mode of operation, separate PIDN control law and pulse width modulation ( PWM) system is developed in control topology under voltage feedback control method. Auto mode transition is realized based on DC bus voltage. Load and line regulations in both buck and boost mode of BBC are realized based on load voltage. The constructed control logic offers accurate bidirectional voltage regulation which ensures precise power transfer in both the directions. Battery charging and discharging characteristics are realized. PIDN control law is compared with proportional, integral, derivative (PID) control law.