Range maximisation of electric vehicles through active cell balancing using reachability analysis

Due to internal differences between cells inside a battery pack, active cell balancing during discharging potentially leads to an extension of the range of electric vehicles. This paper poses range maximisation of electric vehicles as a reachability problem. It is solved by converting this reachability problem into a feasibility problem for a given range. This leads to a large-scale nonlinear feasibility/optimisation problem, which we propose to solve using sequential linearisation of the dynamics and a dual decomposition. This method provides the necessary balancing currents to extend and maximise the range of the vehicle, if the drive cycle, and the model parameters and states are completely known. This result shows the maximum potential for range maximisation through active balancing and can serve as a benchmark for evaluating controllers which are applicable in real-time.