The energy storage battery pack consists of a large number of low-voltage battery cells.The states-of-charge(SOC)of cells are different due to the difference in their characteristics,which causes some cells to be over-discharged during the charging process.To avoid this phenomenon,a equalizing charger based on multi-winding transformer and cascaded double-voltage rectifiers is proposed,and its characteristics are compared with those of a centralized passive equalizing charger.Its operation principle is analyzed,and its equivalent circuit is obtained.The buffer inductance of the novel equalizing charger and the turn ratio of the transformer are also optimized.A control strategy of single voltage-loop is put forward,which can guarantee the charging at two stages,i.e.,constant-current and constant-voltage.In addition,the influence of the voltage difference between cells on the transformer operation is analyzed.Simulation results show that the proposed charger can achieve a high charging efficiency while satisfying the requirement of voltage equalization between cells.
关键词
充电器/均衡器/倍压整流级联/恒流恒压充电/等效电路
Key words
Charger/equalizer/cascaded double-voltage rectifiers/constant-voltage and constant-current charging/equivalent circuit
维普
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