A　balance　control　scheme　of　state　of　charge　(SOC)for　distributed　energy　storage　systems　is　proposed　to　deal　with　the　problem　that　inconsistencies　of　charge　and　discharge　degree　of　lithium　batteries　lead　to　the　over-charge/over-discharge　of　the　batteries,　and　shorten　the　life　of　batteries　in　an　energy　storage　system.　A　distributed　energy　storage　structure　with　a　single　battery　power　module　series　is　adopted　and　estimations　of　SOC　of　single　lithium　batteries　are　used　as　control　object.　An　allocation　formula　of　weighting　factors　is　designed　based　on　balance　of　SOC　to　adjust　the　charge　and　discharge　rate　of　each　single　lithium　battery　dynamically　and　to　achieve　the　SOC　balance　of　the　distributed　energy　storage　system,　which　breaks　the　double-stage　balance　control　mode　in　the　traditional　battery　pack　balance　and　eliminates　the　power　loss　caused　by　the　energy　transfer　between　the　battery　cells　in　the　group.　Moreover,　the　double　closed-loop　control　of　load　voltage　regulation　and　SOC　balance　control　are　adopted　to　ensure　the　stability　of　the　system　operation　during　the　balance　process.　Simulation　results　and　a　comparison　with　the　traditional　balance　control　mode　show　that　the　proposed　balance　control　scheme　effectively　realizes　the　dynamic　balance　control　of　the　energy　storage　system,　ensures　the　load　voltage　stability　regulation,　and　reduces　the　complexity　of　the　system　control.　©　2019,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.