A Multifunctional Control Algorithm for Smart Battery Packs

Battery energy storage systems (BESS) are rapidly gaining prominence, driven by the growing demand of the electric mobility sector and stationary applications. However, conventional solutions that rely on the series/parallel association of battery cells present some limitations, notably their low operational flexibility and fault tolerance. On the other hand, smart batteries, i.e. battery cells with integrated power converter, represent a promising solution that allows better energy sharing, active balancing, fault tolerance, and extended lifetime. This paper presents a multifunctional control algorithm designed for BESS using smart batteries. The proposed strategy integrates four key functionalities: (i) pulsed-current operation to extend battery lifespan; (ii) state-of-charge (SOC) balancing based on duty-cycle control; (iii) fault-tolerant operation through selective bypassing of defective batteries; and (iv) a safety mode to reduce output voltage for maintenance and protection. These features are enabled by a warm redundancy scheme and a master–follower digital control architecture based on half-bridge smart battery modules. The algorithm ensures seamless coordination between all functionalities without increasing the power burden on active batteries. The approach is validated through computer simulations, controller hardware-in-the-loop (c-HIL) experiments, and results on a prototype with three smart batteries, demonstrating its effectiveness and scalability for different system sizes and applications.