中文摘要：

为了研究并网永磁直驱型风力发电（PMSG）系统的振荡问题,建立了基于PQ解耦控制的PMSG系统的小信号模型。用特征值分析法和相关因子分析方法,找出了系统所有的振荡模态、特征频率和主导每种振荡模态的状态变量,并用基于Copula理论的分布估计算法寻找最优的PI控制器参数组合。通过MATLAB/Simulink平台进行时域仿真,验证了各种振荡模态的存在。在不改变系统稳定性的前提下,依次改变变流器的控制参数,研究了系统的次同步控制相互作用、次同步振荡和低频振荡模态的变化情况。利用最佳PI控制器参数对所建PMSG系统模型进行模态分析,仿真结果验证了所提模型的正确性。

英文摘要：

A small-signal model of PMSG（Permanent Magnet Synchronous wind Generator） based on PQ decoupling control is built to study the oscillation of grid-connected PMSG system. The oscillation modes of the system,the characteristic frequency and the dominant state variables of each oscillation mode are found out by eigenvalue analysis method and correlation factor analysis method,and the optimal parameter combination of PI controller is found by estimation of distribution algorithm based on Copula theory. The time-domain simulation is carried out on the MATLAB/Simulink platform to verify the existence of various oscillation modes. Without changing the stability of the system,the sub-synchronous control interaction mode,sub-synchronous oscillation mode and low frequency oscillation mode of the system are studied by changing the converter control parameters in turn. The modes of the established PMSG model are analyzed with the optimal PI controllers＇ parameters,which verifies the correctness of the proposed model.