风电场内机群间次同步振荡相互作用

Interaction of sub-synchronous oscillation between wind turbine clusters in wind farm

大型风电场内部包含大量控制参数各异、运行状态不同甚至类型多样的风电机组,其并网引发的次同步振荡问题日益凸显。研究了风电场内部不同风电机群之间次同步振荡相互作用及其影响因素,从而明确次同步振荡在风电场内的演化过程;建立了直驱风电场的并网导纳模型;应用广义奈奎斯特判据分析了风电场内不同风电机群并网的次同步振荡稳定性,在此基础上研究了风电场内不同风电机群之间的次同步振荡相互作用。结果表明,"振荡机群"能够引起"稳定机群"也发生次同步振荡,二者的并网机组台数比例对风电场次同步振荡特性具有显著的影响,"振荡机群"的锁相环参数对整座风电场的次同步振荡频率具有重要的影响。在MATLAB/Simulink中搭建了直驱风电场的并网仿真模型,时域仿真结果验证了上述理论分析的正确性。

There are a large number of wind turbines with different control parameters,different operation states and even various types in a large-scale wind farm,and the SSO(Sub-Synchronous Oscillation)problem caused by their grid-connection becomes increasingly prominent.The SSO interaction between different wind turbine clusters in a wind farm and their influential factors are studied,so as to clarify the SSO evolution process in wind farm.The grid-connected admittance model of PMSG(Permanent Magnet Synchronous Generator)wind farm is established.The generalized Nyquist criterion is applied to analyze the SSO stability of different grid-connected wind turbine clusters in wind farm.Based on these,the SSO interaction between different wind turbine clusters in wind farm is studied.The results indicate that the“stable wind turbine cluster”also occurs SSO because of the“oscillating wind turbine cluster”.The ratio of their grid-connected wind turbine number has a significant influence on SSO characteristics.The phase locked loop parameters of“oscillating wind turbine cluster”have an impact on SSO frequency of the entire wind farm.The gridconnected simulation model of PMSG wind farm is built in MATLAB/Simulink and the time-domain simulative results verify the correctness of above theoretical analysis.