扩张状态观测器在双馈风机虚拟惯量控制转速恢复中的应用

Application of Extended State Observer in Wind Turbines Speed Recovery After Inertia Response Control

双馈风机虚拟惯量控制通过在系统频率变化时利用附加功率控制释放一定的旋转动能或吸收一定的电能,从而为系统提供等效惯量。但风机在采用虚拟惯量控制后其转速会偏离最优转速,需要施加转速恢复控制。现有的基于比例(P)或比例积分(PI)控制器的转速恢复方法存在参数难以调节、恢复速度慢、容易引起频率的二次跌落等问题,因此需要有合适的控制策略使其恢复最优转速。该文提出了基于扩张状态观测器的双馈风机转速恢复策略,通过扩张观测器较为准确地动态估计风电机组捕获和输出的机械功率,进而通过设计加速功率曲线在避免二次频率跌落的前提下,提升转速恢复速度。动模实验验证了该方法的有效性。

The inertia response control of double-fed induction generators （DFIGs） can release kinetic power to power system or converts power from grid to kinetic power when frequency deviate from the normal range so that the DFIGs can provide inertia for power system. But the speed of DFIGs will deviate the optimal speed after inertia response control, hence a strategy for speed recovering is necessary. The traditional P/PI controller based speed recovery strategy is difficult to set parameters and easily result in second frequency dip. An extended state observer based DFIG-Based WTG speed recovery strategy wae proposed. This strategy earl accelerate the speed of recovering and mitigate the adverse impact of speed recovery on system frequency. At last, a dynamic simulation on a testing bed was proposed.