基于逆系统方法的直驱永磁同步风电机组并网系统频率控制策略OA

Tooptimize the frequency regulation effect ona direct-drive permanent magnet synchronous generator(D-PMSG)grid-connected system,a frequency control strategy for the D-PMSG grid-connected system based on an inverse system method is proposedin this paper.First,the correction coefficient of the maximum mechanical power tracking curve for the wind turbine output is selected as acontrol variable,and a nonlinear system model for the D-PMSG grid-connected system is established.By applying the inverse system method,the analytical expression form of the optimal control law for the reference value of D-PMSG output active power is derived.The problem of manually presetting the initial droop coefficient in the existing variable droop control strategies is avoided,and the adaptive changein the con-trol variable ofthe wind turbine following the system's operating state is realized,enabling the D-PMSG to dynamically-regulate frequency according to load disturbances and changes inthe output power of synchronous generators.Second,D-PMSG rotor speed function and rotor speed recovery function are introduced into the optimal control law,so as to avoid excessive decrease in the D-PMSG rotor speed and achieve a smooth recovery of D-PMSG rotor speed.Finally,the effectiveness of theproposed frequency control strategy for the D-PMSG grid-connected system based on the inverse system method is verified through simulations,providing a new approach forresearch on the frequency control strategy-forthe D-PMSG grid-connected system.