摘要
由于各并联储能单元的线路参数、初始荷电状态(SOC)不相同,在系统运行时会导致不同储能单元的SOC不平衡,影响蓄电池寿命。提出一种基于SOC均衡的鲁棒下垂控制方法,以平衡各储能单元的充放电SOC,并克服线路阻抗对均衡的影响。该方法将直流下垂控制系数与蓄电池的SOC关联,使各个储能单元能根据其SOC动态调节负荷电流。同时利用直流母线公共点电压作为反馈信号,将各个储能单元的线路阻抗等效为储能变换器的部分输出阻抗,有效减小线路阻抗不匹配对负荷电流分配和SOC均衡精度的影响,并可实现直流母线电压的稳定。对系统进行了稳定性分析,确定了控制参数的选择范围,经MATLAB/Simulink软件仿真,结果验证了该方法的有效性。
When the system operates,different line parameters and initial state of charge (SOC) of parallel distributed energy storage contribute to unbalanced SOC of different energy storage units,which reduces life of the battery.A robust droop control method based on SOC balancing control is proposed to balance the charging and discharging states of energy storage units and to overcome the influence of line impedance on balancing control.This method combines DC droop control coefficient with SOC of the battery to make every energy storage unit dynamically adjust the load current according to its SOC.Meanwhile,voltage of DC bus common point is used as the feedback signal to make line impedance of energy storage units equivalent to partial output impedance of energy storage converters,which effectively reduces the influence of line impedance mismatch on load current distribution and the accuracy of SOC balancing control and keeps the voltage of DC bus stable.After analyzing the system stability and determining the range of control parameters,a MATLAB/Simulink simulation model is built,and the results from the model verify the effectiveness of the method.
作者
杨子萱
曾进辉
何东
YANG Zi-xuan;ZENG Jin-hui;HE Dong(College of Electrical and Information Engineering,Hunan University of Technology,Zhuzhou 412007,China)
出处
《电工电气》
2022年第11期1-10,共10页
Electrotechnics Electric
基金
湖南省自然科学基金项目(2020JJ6082)。
关键词
直流微电网
分布式储能
SOC均衡
下垂控制
DC microgrid
distributed energy storage
SOC balancing control
droop control
