摘要
针对独立运行的多储能直流微电网系统中荷电状态(State of Charge,SOC)均衡问题,提出一种基于模糊控制的改进下垂控制策略。独立运行时,光伏发电单元运行于最大功率点跟踪模式,当系统内部存在功率缺额时,通过储能单元充放电来维持母线电压的稳定。该控制策略通过利用各储能单元的SOC并建立相应模糊控制规则来实现储能单元间的SOC及负荷功率均衡,为提高均衡速度和精度,在模糊控制器输入参数中引入加速因子。在储能单元充放电过程中,模糊控制器随着SOC值的改变动态地调整下垂系数的大小,从而实现储能单元间的SOC均衡及负荷功率合理分配。最后通过Matlab/Simulink仿真模型,验证了所提控制策略的正确性。
Aiming at the state of charge(SOC)equilibrium in a isolated DC microgrid system with multiple energy storage units,an improved droop control strategy based on fuzzy control is proposed.In the isolated mode,the photovoltaic power generation unit operates in the maximum power point tracking mode.When there is a power shortage in the system,the energy storage unit is charged and discharged to maintain the stability of the bus voltage.The control strategy achieves SOC and load power balancing between energy storage units by utilizing the SOC of each energy storage unit and establishing corresponding fuzzy control rules.To improve the equalization speed and accuracy,an acceleration factor is introduced into the input parameter of the fuzzy controller.During the charging and discharging process of the energy storage unit,the fuzzy controller dynamically adjusts the size of the droop coefficient as the SOC value changes,thereby achieving SOC equalization and reasonable distribution of load power between the energy storage units.Finally,the correctness of the proposed control strategy is verified by the Matlab/Simulink simulation model.
作者
黄翔
李留根
HUANG Xiang;LI Liu-gen(College of Electrical&New Energy,China Three Gorges University,Yichang443002,China)
出处
《电力学报》
2019年第4期375-381,共7页
Journal of Electric Power
关键词
直流微电网
下垂控制
模糊控制
储能系统
DC microgrid
droop control
fuzzy control
energy storage system
