Design of DSP Controlled Passive Cell Balancing Network based Battery Management System for EV Application

Growing response for Electric Vehicles (EV) across the world is an implication of techno-economical efforts targeted to mitigate the challenges related to fossil fuels. Energy storage powering EVs is a very critical component. A battery pack used as energy storage in EVs uses many battery cells connected in series and parallel. These battery cells need close monitoring and management system during its operation in EVs. Such a system referred to as `Battery Management System' (BMS) ensures a safe operating envelope while increasing battery power delivery capabilities and improving lifetime. The cell voltage balancing along with the State of Charge (SOC) and State of Health (SOH) monitoring are some of the critical functions of BMS. For EVs to become the best techno-commercial alternative for gasoline-based vehicles, BMS and battery packs will play a very crucial role. This paper highlights the state of the art of BMS and illustrates the passive cell balancing network design for Lithium-Iron-Phosphate (LiFePO4) batteries based on Digital Signal Processor (DSP) TMS320F28379D controller. Some key simulation and hardware results are presented to demonstrate the SOC estimation using the Coulombs counting method and battery cell balancing mechanism.