计及锁相环的直驱风电机组间相互作用模型及机理分析

Interaction model and mechanism analysis of direct-drive wind turbines considering PLL

为了研究直驱风电机组间的相互作用,提出考虑锁相环的直驱风电机组间相互作用模型及分析方法。首先考虑频率耦合特性,利用谐波线性化方法建立单台直驱风电机组序导纳模型。其次考虑锁相环建立2台直驱风电机组间相互作用模型,研究2台机组之间的相互作用机理。然后根据锁相环动态特性,将其分为衰减振荡状态和非振荡状态,分析锁相环在不同情况下对2台直驱风电机组间相互作用的影响,研究总结了锁相环对2台机组间相互作用振荡特性的作用规律。最后对2台直驱风电机组并网系统进行时域仿真,并与频域分析进行对比,验证了考虑锁相环的2台机组间相互作用模型及分析方法的合理性。

In order to study the interaction of direct-drive wind turbines,an interaction model and analysis method for direct-drive wind turbines are proposed considering PLL(Phase Locked Loop).Firstly,considering the frequency coupling characteristics,the harmonic linearization method is used to establish the sequence admittance model of single direct-drive wind turbine;Secondly,the interaction model between two direct-drive wind turbines is established to study the interaction mechanism.Then,according to the dynamic charac-teristics of PLL,it is divided into attenuated oscillation state and non-oscillatory state,the influence of PLL on the interaction of two direct-drive wind turbines under different modes is analyzed,and the action law of PLL on the interaction oscillation characteristics of two direct-drive wind turbines is studied and summa⁃rized.Finally,the time-domain simulation of the grid-connected system with two direct-drive wind turbines is conducted and compared with the frequency-domain analysis to verify the rationality of the interaction model between two units considering PLL and analysis method.