Modeling and Analysis of Series-Parallel Switched-Capacitor Voltage Equalizer for Battery/Supercapacitor Strings

A series-parallel switched-capacitor (SC) power converter is reconfigured as a new voltage equalization circuitry for series-connected batteries or supercapacitors in this paper. The model of the new voltage equalizer is derived and successfully used to analyze the equalization speed and the energy loss. It is a very useful tool to analyze and design the SC-based equalization systems to meet different balancing speed requirements. The analysis and modeling methods can be extended to other SC-based voltage-balancing systems. A prototype is built and the experimental results are provided to confirm the theoretical analysis and the modeling method.