风储直流微网系统建模及稳定性分析

Wind Storage DC Microgrid System Modeling and Stability Analysis

在风储直流微网系统中,各个变换器之间的相互作用会对整体系统稳定产生一定的影响,因此研究其稳定性是十分必要的。此处首先根据风储直流微网拓扑结构及其控制策略推导了各个变换器的阻抗或导纳模型,得到风储直流微网系统的阻抗比,接着结合Nyquist稳定性判据,分析了在不同网侧变流器电压环比例参数、储能系统电流环控制参数、储能放电状态下储能系统不同容量配比对风储直流微网系统稳定性的影响。最后通过实验验证了稳定性分析的结果。

In the wind storage DC microgrid system,the interaction between each converter will have a certain impact on the overall system stability,so it is very necessary to study its stability.Firstly,according to the topology and control strategy of the wind storage DC microgrid,the impedance or admittance models of each converter are derived,and the impedance ratio of the wind storage DC microgrid system is obtained.Then,combined with the Nyquist stability criterion,the voltage loop proportional parameters of the converter on different grid sides,the current loop control parameters of the energy storage system,the influence of different capacity ratio of energy storage system on the stability of wind storage DC microgrid system under energy storage discharge state are analyzed.Finally,the results of stability analysis are verified by experiments.