基于SOC与SOH的全钒液流电池并联控制策略

Parallel Control Strategy for Vanadium Redox Flow Batteries Based on SOC and SOH

  • 摘要: 针对全钒液流电池(VRFB)并联系统在采用传统均流策略时出现的能量分配不均、电池健康状态恶化以及直流母线电压下降等问题,本文提出一种基于荷电状态(SOC)与健康状态(SOH)协同控制的改进均流策略。该策略在传统平均均流框架基础上,将SOH权重项与SOC均衡项以加性分离形式引入均流环,动态调节各储能单元的电流参考值,使SOC与SOH较高的单元承担更多功率,实现负荷合理分配与SOC均衡。同时,增设二次电压补偿环节,有效抑制直流母线电压跌落,使母线电压稳定在理想值。利用MATLAB/Simulink搭建全钒液流电池并联系统仿真模型,在SOC差异、SOH差异、SOC/SOH复合差异及负载突变等工况下验证了所提策略的有效性;半实物仿真进一步验证了其工程可行性。研究结果为全钒液流电池并联系统的可靠运行与效率提升提供了理论参考。

     

    Abstract: Based on the issues of uneven power distribution, deterioration of battery health, and dirert current bus voltage drop in parallel-connected vanadium redox flow battery (VRFB) systems under traditional current-sharing strategies, we proposes an improved current-sharing strategy based on the coordinated control of state of charge (SOC) and state of health (SOH). Built upon the conventional average current-sharing framework, the proposed strategy introduces the SOH weight term and the SOC equalization term into the current-sharing loop in an additive separation form, dynamically adjusting the current reference of each energy storage unit, enabling units with higher SOC and SOH to undertake more power, thereby achieving rational load distribution and SOC equalization. Meanwhile, a secondary voltage compensation link is added to effectively suppress dirert current bus voltage drop and maintain the bus voltage at the desired value. A simulation model of the parallel-connected VRFB system is established using MATLAB/Simulink, and the effectiveness of the proposed strategy is validated under multiple operating conditions, including SOC discrepancy, SOH discrepancy, combined SOC/SOH discrepancy, and load sudden change. Hardware-in-the-loop simulation further verifies its engineering feasibility. The research results provide a theoretical reference for the reliable operation and efficiency improvement of parallel-connected VRFB systems.

     

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