Control-Oriented Design and SIL–PIL Validation of a Bidirectional Synchronous Buck Converter Under Constant-Power Operation

Abstract

This study investigates the modeling, digital control, and implementation-oriented validation of a bidirectional synchronous buck converter conceived as the DCDC stage of a future electric vehicle on-board charger (OBC). A constant-power control strategy is employed to support both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operation through a unified current regulation framework. The power stage incorporates a $560 \mu \mathrm{H}$ output inductor and a $0.47 \mu \mathrm{~F}$ capacitor selected to limit current ripple while maintaining adequate control bandwidth. Validation is carried out using a progressive Model-in-the-Loop (MIL), Software-in-the-Loop (SIL), and Processor-in-the-Loop (PIL) workflow, with identical controller parameters maintained throughout. Real-time execution on a Texas Instruments F28379D platform enables assessment of sampling, discretization, and processor-level effects. The results indicate consistent power tracking across the $\pm 50 \mathrm{~W}$ operating range and close correspondence between SIL and PIL responses, supporting the feasibility of the proposed architecture for future integration within a complete bidirectional OBC system.