Temperature-Adaptive Branch Rotation Within an Efficiency Oriented Control Framework for Interleaved Bidirectional DC–DC Converters Applied to Battery Energy Storage Systems

Bidirectional Interleaved Converters (BICs) are widely used in Battery Energy Storage Systems (BESS) due to their modular structure, high efficiency, and reduced current ripple. However, under partial-load operation, conventional control strategies with fixed or purely current-based phase shedding repeatedly activate the same converter branches, resulting in increased switching losses, thermal imbalance, and uneven aging of power semiconductors. This paper proposes a temperature-adaptive control strategy for BICs aimed at improving light-load efficiency while actively balancing thermal stress between converter branches. The approach combines a current-adaptive phase-shedding algorithm with a temperature-based branch rotation mechanism, where real-time transistor junction temperature is used as the primary decision variable for branch activation and deactivation. An electro-thermal real-time simulation model of a two-branch BIC is developed using the Controller Hardware-in-the-Loop (CHIL) methodology in the Typhoon HIL environment. The proposed control strategy is validated through real-time CHIL experiments in both boost and buck operating modes under representative battery load profiles. The results demonstrate a reduction in average and peak transistor junction temperatures, improved thermal distribution between converter branches, and more uniform branch utilization, while preserving stable current regulation and power flow. The presented method represents a practical extension of conventional phase-shedding techniques and provides an implementation solution for improving efficiency and reliability of BICs in BESS applications.