基于弱电网的光伏储能系统小干扰稳定性分析

Small Signal Stability Analysis of Photovoltaic Energy Storage System Under Weak Grid

建立了接入弱电网的光伏储能系统小信号模型,解决了其小扰动稳定性问题。基于特征值分析法,分析了电网强度、光伏系统输出功率、控制环参数对光伏储能系统稳定性的影响。结果表明,弱电网下控制环路的带宽对系统稳定性的影响很大。随着储能系统锁相环带宽的增大,系统的稳定性先下降后提高;随着光伏系统直流电压环带宽的增大,系统的稳定性先增大后减小再增大。最后,在Matlab/Simulink中搭建了光伏储能系统接入弱电网的时域模型,验证了小干扰稳定性分析的正确性。

The paper establishes the small signal model of photovoltaic energy storage system integrated into weak grid to solve its small signal stability problem.Based on eigenvalue analysis,the paper analyzes the influence of the grid strength,PV output power and control loop parameters on the stability of the photovoltaic energy storage system.The results show that the bandwidth of control loop under the weak grid has a great influence on the stability of the system.The stability of the system first decreases and then increases with the increasing phase-locked loop bandwidth of the energy storage system.With the increasing DC voltage loop bandwidth of the PV system,the stability of the system first increases and then decreases and then increases.Finally,the paper establishes the time-domain model of the photovoltaic energy storage system connected to the weak grid in Matlab/Simulink,verifying the correctness of small signal stability analysis.