基于虚拟惯性控制的光伏直流微电网稳定性分析

Stability analysis of photovoltaic DC microgrid based on virtual inertia control

在“双碳”目标下,直流微电网呈现低惯性特性,这对系统稳定运行造成不利影响。建立基于母线节点导纳网络的负反馈模型,利用其等效开环函数对系统稳定性进行分析。针对系统稳定裕度不足,提出将虚拟惯性控制引入光伏单元,实现光照变化较大情况下的母线电压平滑输出。理论分析与实验结果表明,所提控制方法在保证光伏利用率的基础上,对母线电压波动的抑制效果明显。

Under the goal of“double carbon”,DC microgrid show low inertia characteristics,which adversely affects the stable operation of the system.A negative feedback model based on the bus node conductor network is established,and its equivalent open-loop function is used to analyze the system stability.Aiming at the lack of system stability margin,it is proposed to introduce the virtual inertia control into the photo⁃voltaic unit,which realizes the smooth output of bus voltage under the situation of large light intensity variation.Theoretical analysis and experimental results show that the proposed control method is effective in suppressing the bus voltage fluctuation on the basis of ensuring the photovoltaic utilization rate.