Simplified control strategy for an inhomogeneous series-connected battery string

An active cell balancing scheme has been presented, that can deal with gross cell parameter mismatches, including cell capacity, as in second life cells. Taking into account the unavoidable uncertainty in the estimated cell State of Charge (SoC) and the slow dynamics of an electrochemical cell, and by drawing a contrast with a PI control scheme, the suitability of model predictive control in this application has been highlighted. Studies carried out on a representative prototype have been used to highlight practical issues.