A Mesh-Structured Switched-Capacitor Equalizer for Lithium-Ion Battery Strings of Electric Vehicles

A mesh-structured switched-capacitor (SC) equalizer (MSSCE) is proposed to improve the balancing speed and efficiency at any imbalanced cell voltages. The proposed MSSCE can transfer energy simultaneously among cells with more and shorter balancing paths by using less components, which offers the advantages in the balancing speed, efficiency, reliability, size, and cost. A prototype for four series-connected battery cells was set up to validate the validity of the proposed topology. Experiment results show that the proposed MSSCE can balance automatically cell voltages with a strong robustness and high balancing efficiency.