System Modeling, Performance Evaluation, and Control of Battery System Charge Balance

As the major energy storage device and power supply source in numerous energy applications, battery systems often face the issue of charge imbalance among battery cells/modules/packs, which can accelerate battery degradation, cause more energy loss, and even incur fire hazard. This thesis is focused on the system modeling, performance evaluation, and control of battery systems with various charge balancing circuits. Specifically, based on the proposed mathematical models for battery charge equalization systems, computationally efficient methods are developed to estimate the evolution of battery state of charge and to evaluate critical system performance measures. Then, near-optimal battery cell/module reconfiguration algorithms are proposed to expedite the battery charge equalization process. Besides, for the battery power modules, a new current allocation method based on charging/discharging spaces is derived for the coordinated control of module charge balance and total power efficiency. Extensive numerical experiments are carried out and the results are compared with those obtained from computer simulations and/or circuit experiments to justify the estimation accuracy and computational efficiency of the proposed methods