Design of balancing system for traction batteries

The paper deals with state of art about balancing systems, battery management system (BMS) and design of these systems. Proposed balancing system consists of two series-connected batteries with a flyback input connected to each. The flyback output is connected to the output of both batteries. Paper contains all the important calculations for the flyback converter. It deals with calculation of RMS and AV values of currents of primary and secondary side of the transformer and circuit components as well. Consequently, designed BMS system is modeled and evaluated through simulation using PLECS. Simulation model also contains lithium battery model together with model of flyback converters and model of the balancing system itself considering its control. Verification of the operational scenarios are realized, while evaluation of system performance from temperature and efficiency point of view is also given.