交直流混合微电网中源荷两侧存在功率波动的问题,由蓄电池和超级电容器组成的混合储能接入微网可抑制功率波动,为此提出一种基于虚拟阻抗和模糊算法结合的交直流微电网混合储能功率协调策略.首先,通过复合虚拟阻抗实现混合储能的功率自主初次分配;其次,综合分析复合虚拟阻抗参数和滤波时间常数对功率分配的影响,提出一种功率分配调整方法并推导出模糊控制规则,利用模糊算法根据超级电容器荷电状态和所承担功率自适应优化混合储能的输出功率;再次,自适应调整交直流互联变换器中的功率来提升混合储能的调节能力.最后,通过MATLAB/Simulink仿真实验证明所提策略既能有效平抑源荷侧的功率波动,消除直流母线电压偏差,又能改善超级电容器过度充放的问题,从而延长设备的使用寿命.

A hybrid energy storage system consisting of batteries and supercapacitors can be integrated into the microgrid, to mitigate the power fluctuations on both sides of the source and load sides, which is a common issue in AC/DC hybrid microgrids. This paper proposes a power coordination strategy for hybrid energy storage in AC/DC microgrids based on virtual impedance and fuzzy algorithm optimization. First, the initial power allocation for hybrid energy storage is autonomously determined using composite virtual impedance. Then, a comprehensive analysis is conducted to assess the influence of composite virtual impedance parameters and filtering time constant on power distribution. Based on this, a power distribution adjustment method is proposed, and fuzzy control rules are derived. The fuzzy algorithm is used to adaptively optimize the output power of hybrid energy storage based on the state of charge and the power demond on the supercapacitor. Finally, the power in the AC/DC interlinking converter is adaptively adjusted to enhance the regulation ability of hybrid energy storage. The simulation results in MATLAB/Simulink experiments demonstrate that the proposed strategy can effectively suppress power fluctuations on both the source and load sides, eliminate DC bus voltage deviation, and prevent the issues such as over-charging and over-discharging of supercapacitors, thereby extending the service life of the equipment.