SCESS-DFIG发电系统宽时间尺度功率波动的平抑控制方法

In order to smooth the power fluctuation caused by high penetrations of wind power in a wide time scale,an approach combining the variable pitch control with super-capacitor energy storage power control is proposed. The super-capacitor is employed to enable bidirectional regulation of the wind farm active power fluctuation in a rapid and accurate way,and consequently the short time scale fluctuation of the output power is effectively controlled. The power redundancy is obtained using the load reduction variable pitch control. The auxiliary power adjustment will be triggered when the super-capacitors' voltage violates the voltage limit,which can not only optimize the energy mana-gement of super-capacitors,but also achieve the wide time scale power fluctuation suppression. Based on the model establishment of DFIG(Doubly-Fed Induction Generator),DC bidirectional up/down converter and super-capacitor energy storage unit,a wind farm composed of three SCESS-DFIGs(DFIGs with Super-Capacitor Energy Storage System) is simulated. Based on the simulation of the operating conditions with the same rated parameters,different wind speed curves,and different super-capacitor initial voltages,the validity of the proposed control strategy is verified.