A Bimodal Multichannel Battery Pack Equalizer Based on a Quasi-Resonant Two-Transistor Forward Converter

In the application of a long series battery group, an inter-pack imbalance is inevitable. No intra-pack cell equalizer can prevent pack-level over-discharge. A bimodal, multichannel pack based on quasi-resonant, two-transistor forward converter proposed to solve this problem and achieve tradeoff between balancing efficiency speed. This has two modes: pack-to-pack-group pack-to-any-pack (P2PG&AP) mode direct-pack-to-pack (DP2P) mode. P2PG&AP mode, realize full-switching-cycle (FSC) equalization through three channels, transfer energy from any both whole group inside group. addition, it effectively clamp transformer-induced voltage using secondary side magnetic reset structure (STMR) reduce total turns transformer coil 70 50 via boost (SBC). DP2P zero gap (ZVG) equalization. prototype was tested at different switching frequencies LC values validate theoretical analysis optimize bimodal hybrid operation. Experiment results including higher than 89.66% minute-level time under distributions show that topology demonstrates excellent performance.