计及直驱风机差异性的并网风电场次同步频段小干扰稳定性  

Small Disturbance Stability of Grid-connected Wind Farms in Sub-synchronous Frequency Band Considering Difference of PMSGs

作　　者：代晓峰 付强[1] 杜文娟 任必兴 DAI Xiaofeng;FU Qiang;DU Wenjuan;REN Bixing(School of Electrical Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China;Jiangsu Electric Power Test Research Institute Co.,Ltd.,Nanjing 211103,Jiangsu Province,China)

机构地区：[1]四川大学电气工程学院,四川省成都市610065 [2]江苏省电力试验研究院有限公司,江苏省南京市211103

出　　处：《电网技术》2023年第7期2743-2754,共12页Power System Technology

基　　金：江苏省自然科学青年基金项目(BK20210057):“多电力电子换流器高度密集电网振荡传播机理与量测数据驱动振荡定源理论研究”。

摘　　要：大规模直驱风机(permanent magnet synchronous machines,PMSGs)的接入会加剧电力系统动态失稳风险,为降低电力系统状态空间模型阶数,提升模式计算效率,现有分析方法常忽略直驱风机间的差异性,实现风电场模型降阶。然而,实际直驱风机的运行工况存在一定差异,相似性假设容易导致分析结果产生误差,影响稳定性判定的可信度。分析了在次同步频段,直驱风机运行工况差异性对风电场小干扰稳定性的影响,证明了:直驱风机运行工况的变化会改变振荡模式在复平面上的位置,但这些振荡模式的边界仅由风机出力最小和最大运行工况决定。基于此,提出了考虑直驱风机差异性的风电场小干扰稳定性分析方法,预测了直驱风机在不同运行工况下振荡模式在复平面上的区间,实现了对差异化直驱风机并网稳定性的快速判定,有助于实际风电场并网失稳风险的及时预警。最后,基于差异性直驱风机的仿真算例,验证了所提方法和分析结论的有效性。Large-scale permanent magnet synchronous machines(PMSGs)connected power system will aggravate the risks of dynamic instability.For reducing the orders of the state space model of the power system and improving the mode calculation efficiency,the existing analysis methods often ignore the differences between the PMSGs.However,with the differences in the actual operating conditions of the PMSGs,the similar assumptions may lead to the errors of the analysis results and affect the reliability of the stability judgment.This paper analyzes the influence of the operating condition differences of directly-driven fans on the small signal stability of the wind farm in the sub-synchronous frequency band.The results prove that the changes of operating conditions of the PMSGs may vary the positions of oscillation modes on the complex plane,while the boundaries of these oscillation modes are only determined by the minimum and the maximum operating conditions of the PMSGs.Based on this,a method of the small disturbance stability analysis of the wind farm considering the differences of the PMSGs is proposed.The interval of the oscillation mode of the PMSGs on the complex plane under different operating conditions is predicted,realizing the fast judgment of the grid connection stability of the large-scale differentiated PMSGs,which is helpful for the timely early warning of the grid connection instability risks on the actual wind farm.Finally,based on the simulation examples of the PMSGs,the effectiveness of the proposed method and the analysis conclusions are verified.

关 键 词：直驱风机 差异性 小干扰稳定性 振荡模式区间 

分 类 号：TM721[电气工程—电力系统及自动化]