Fast, Controllable, and Modular Solid State Circuit Breaker Design for Battery Management Systems

Electric power grid is experiencing a growing number of distributed and inertia-free generation resources. To facilitate the growing generation and load demands, and ensure stable operation, energy storage systems, especially behind-the-meter-storage (BTMS), have emerged as a potential candidate. BTMS plays a vital role in grid storage and supports high-power charging for EVs and datacenters, among other applications. However, the potential for thermal runaway and associated safety concerns in the batteries can hamper their widespread adoption. In this work, we provide a solution for the fast and controllable discharge of a cell that is identified as faulty in the battery pack. We do this by incorporating fast circuit breaking using a solid-state circuit breaker (SSCB) which provides active control over the cell connection as opposed to conventional passive solutions. Testing on the simulation platform successfully validated the concept. Controlled discharge testing with 20Ah lithium iron phosphate (LFP) cells between 1C to 10C discharge rates on the hardware prototype supported simulation results. It demonstrated design feasibility and provided essential data for its performance and thermal characteristics, while also revealing limitations that inform areas for further optimization.