Charge Equalization for Series-Connected Battery Cells Using SIMO DC-DC Converter

This paper presents a charge equalization method for series-connected battery cells, using the single-inductor multiple-output (SINIO) DC-DC converter. The battery cells are individually charged according to the corresponding state of charge (SOC) to achieve the charge equalization. The SIMO topology reduces the number of components and circuit size. However, the SIMO DC-DC converter has a cross regulation problem. A novel model predictive current control (MPCC) method is proposed to regulate the SIMO DC-DC converter for suppressing cross regulation. Corresponding current reference assignment algorithms are developed to provide the proper output current references for balancing the battery cells. Simulation studies and comparison are conducted to verify the performance of the proposed charge equalization method.