Multi-layer state of health balancing control for a battery-based energy storage system to extend cycle life based on active equalization circuits
Multi-layer state of health balancing control for a battery-based energy storage system to extend cycle life based on active equalization circuits
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DOI：
10.3389/fenrg.2022.966422
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发表时间：
2022-09
期刊：
影响因子：
5.2
通讯作者：
Xiaohang Li;Xin Yin;Z. Tian;X. Jiang;Lin Jiang;Jeremy Smith
中科院分区：
文献类型：
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作者：
Xiaohang Li;Xin Yin;Z. Tian;X. Jiang;Lin Jiang;Jeremy Smith
健康状态（SoH）不平衡导致基于电池的能量存储系统（BESS）的容量浪费和循环寿命缩短，这要求对BESS的并联连接的组和串联连接的单元进行SoH平衡控制。本研究提出了一种多层SoH平衡控制，以延长循环寿命的BESS。对于串联的电池单元，采用基于反激变换器的有源均衡电路进行单元间能量交换，控制单元放电深度，实现SoH平衡。对于并联电池组，基于SoH均衡原理，通过分配输出功率来均衡SoH，并考虑了串联电池组间双向均衡电流对电池组的最小功率分配约束。由于该方法通过利用有源均衡电路在不同SoH的电池之间传递能量来实现SoH平衡，因此与耗散能量的无源均衡类型相比，它可以实现更高的容量和能量利用效率以及更低的热释放。以一个3组15单元的电池储能系统为例，验证了该方法的有效性。仿真结果表明，与采用相同反激变换器的有源SoC平衡方法和无源多层SoH平衡方法相比，该方法可使BESS的循环寿命分别延长约52.9%和18.3%。
State of health (SoH) imbalance causes capacity waste and cycle life reduction of the battery-based energy storage systems (BESS), which demands SoH balancing control of the parallel-connected packs and the series-connected cells of the BESS. This study proposed a multi-layer SoH balancing control to extend the cycle life of the BESS. For the series-connected battery cells, active equalization circuits based on the fly-back converter are used to exchange energy between cells and control the depth of discharge (DoD) of cells to achieve the SoH balance. For the parallel-connected packs, SoH is equalized by distributing the output power based on the SoH balancing principle and the minimum power distribution constraints of packs caused by the bidirectional balancing current among the series-connected cells are considered. Because the proposed method achieves the SoH balancing by utilizing the active equalization circuits to transfer the energy between the cells with different SoH, it can achieve higher capacity and energy utilization efficiency and lower heat release compared with the passive equalization typology that dissipates the energy. The effectiveness of the proposed method is verified by a case study based on a 3-packs-15-cells BESS. Simulation results show that this method can prolong the cycle life of BESS by about 52.9% compared with the active SoC balancing method using the same fly-back converter and 18.3% with a passive multi-layer SoH balancing method, respectively.