多运行方式下风电机组变频器参与次同步相互作用的分析与抑制

Analysis and Mitigation of Wind Turbine Converters in Sub-Synchronous Interaction under Multi-operating Conditions

大规模风电经串补线路进行远距离传送存在引发次同步相互作用的风险,系统运行方式、串补度及变频器控制参数为主要影响因素。采用概率法和模式分析相结合,分别在含双馈感应型和永磁同步型风电场系统中,研究多运行方式下风电串补系统的次同步相互作用。利用参与因子进行模式识别,研究了串补度对次同步振荡模式及概率稳定性的影响,引入概率灵敏度指标分析起主导作用的变频器PI控制参数,并基于风电机组变频器提出一种鲁棒抑制次同步相互作用的附加阻尼控制策略。仿真结果表明,双馈风电串补系统中易产生次同步控制相互作用,在网侧变频器加装鲁棒DFIG-PSS能实现其有效抑制,而永磁同步风电机组对这一相互作用具有免疫特性。

Large scale wind power transmitted by series compensated lines are susceptible to the sub-synchronous interaction （ SSI） in long distance. System operating conditions , series compensation degree and PI parameters of the converter control system are the major influence factors on the power system sub-synchronous stability. This paper presents a probabilistic approach combined with modal analysis to study the SSI issues respectively on doubly fed induction generator （ DFIG） system and permanent magnet synchronous generator （PMSG） wind farm system Participation factor （ PF） is utilized to analyze the state variables involved in the SSI for mode identification. The impacts of series compensation degree on the oscillation modes are investigated, and then, probabilistic sensitivity index（PSI ） is proposed to study the dominant converter control parameters on the SSI, a robust supplementary damping control strategy based on wind turbine converter is presented to exploit the SSCI suppression capability. Obtained results show that DFIG-based wind turbine is highly sensitive to the SSCI, a robust power system stabilizer（ PSS） is supplemented to the DFIG grid side converter for SSCI mitigation over a large and pre-specified set of operating conditions, the effectiveness of the proposed approach is validated, whereas, PMSG-based wind turbine is verified to be immune to that interaction.