构网型直驱风机的小信号建模及动态频率支撑策略

Small-signal Modeling and Dynamic Frequency Support Strategy for Permanent Magnetic Synchronous Generator under Grid-forming Control

针对传统构网型直驱风机在大扰动下的频率和功率振荡较大的问题,提出一种动态频率支撑策略。首先对构网型直驱风机进行了详细的小信号建模。其次,通过主导特征根轨迹分析有功频率控制以及交流电压控制环节中参数对频率变化特性的影响,进而提出一种灵活改变控制参数的动态频率支撑策略。最后,在Matlab/Simulink仿真平台上搭建仿真模型,验证了小信号建模的正确性和所提策略的有效性,表明所提策略能有效减小动态过程中的频率和功率振荡。

Aimed at the problem that the frequency and power of a traditional grid-forming permanent magnetic synchronous generator oscillate greatly under large disturbance,a dynamic frequency support strategy is proposed in this paper.First,a detailed small-signal modeling of the grid-forming permanent magnetic synchronous generator is carried out.Second,the influences of parameters in active frequency control and AC voltage control links on the frequency variation characteristics are analyzed through the dominant characteristic root trajectory,and a dynamic frequency support strategy with flexible control parameters is put forward accordingly.Finally,simulations are performed on the Matlab/Simulink platform,which verifies the correctness of small-signal modeling and the effectiveness of the proposed strategy.It is concluded that this strategy can effectively reduce the frequency and power oscillations during the dynamic process.