基于不同网架结构的直流微电网稳定性分析

Stability Analysis of DC Microgrid Based on Different Grid Structures

不同网架结构下的直流微电网系统是否具有稳定性差异尚不明确,亟需开展研究。针对该问题,建立几种典型网架结构下系统的小信号模型,并基于参与因子以及系统特征根的变化,研究不同网架结构下系统参数对系统稳定性的影响规律。结果显示,单独改变源侧控制器参数,不同网架结构下系统的稳定性基本一致,仅存在谐振频率的差异;单独改变负载侧控制器参数,仅影响与负载有关的振荡模态,且负载与线路基本不产生交互作用;单独改变线路参数,由于源网间的交互作用,不同系统间出现稳定性差异。最后,通过仿真验证了理论分析的正确性。

It is not clear whether the DC microgrid system with different grid structures has different stability,which needs to be studied.In order to solve this problem,the small signal models of several typical grid structures are established.Based on the change of participation factors and system characteristic roots,the influence of system parameters on system stability under different grid structures is studied.The results show that the stability of the system under different grid structures is basically the same with only the difference of resonance frequency when the parameters of the controller on the source side are changed alone;when the parameters of the controller on the load side are changed alone,only the oscillation modes related to the load are affected,and the load and the line basically have no interaction;when the parameters of the line are changed alone,due to the interaction between the source network,different systems appear Stability difference.Finally,the correctness of the theoretical analysis is verified by simulation.