采用多元线性回归方法分析短路比对风电并网系统小干扰稳定性的影响

Multiple-Linear-Regression Based Analysis of the Impact of Short Circuit Ratio on Small-Disturbance Stability of Wind Power Grid-Connection Systems

短路比对风电并网系统的小干扰稳定性有重要影响,常规机理性或仿真分析仅关注特定场景下参数的影响,而缺乏全工况下的宏观把握,文章提出多元线性回归方法来解决这一问题。首先介绍风电并网系统中重点关注的两类小干扰稳定性(包括同步稳定性和次/超同步振荡稳定性)的机理与分析方法;其次回顾新能源场景下单机系统短路比定义;然后构建基于多元线性回归的统计性分析方法,通过对大量判稳算例进行回归分析来总体评估小干扰稳定性的影响因素;最后将所述方法分别应用于直驱和双馈风电机组并网系统,分析了短路比对同步稳定性和次/超同步振荡稳定性影响的量化特征。研究结果可用于指导短路比指标在风电系统小干扰稳定性评估中的应用。

The short-circuit ratio has a big impact on the small-signal stability of the wind power grid-connection systems.Conventional mechanism analysis or simulation mainly focuses on the impact of parameters on the stability under specific operating conditions rather than all possible operating conditions.To fill this gap,this paper proposes a method based on multiple linear regressions.In this paper,the mechanism and analysis methods of the two concerned types of smalldisturbance stability(including synchronous stability and sub/super-synchronous oscillation stability)are firstly introduced.Secondly,the definition of short-circuit ratio in the single-infeed wind power systems is reviewed.Then,a statistical analysis method based on the multiple linear regressions is constructed to assess the impact factors by numerous stability analysis cases.Finally,the method is applied to the grid-connected PMSG and DFIG systems to quantify the impact of the shortcircuit ratio on the small-disturbance stability.The results can be used to guide the application of the short-circuit ratio in the small-disturbance stability evaluation of the wind power systems.