【摘要】 研究一种背靠背三电平变流器控制下的直驱永磁风力发电系统,其中机侧变流器采用二极管中点钳位型三电平变流器在转子同步旋转坐标系下对定子电流进行控制,对发电机电流谐波进行抑制。研究三电平变流器的开关状态和调制方法,采用双重傅里叶级数的方法对机侧三电平变流器的谐波特性进行分析,并提出考虑中性点电压平衡的机侧谐波抑制控制策略。对三电平和两电平变流器直驱永磁风力发电系统进行对比仿真实验研究。研究结果表明:在不同转速和负载条件下,三电平拓扑能有效抑制发电机电流谐波,提高发电机组效率。更多还原

【Abstract】 A wind power generation system employing back-to-back three-level converters instead of the traditional two-level machine side converter was presented. The diode neutral point clamped three-level converter in the rotor synchronous rotating coordinate of stator current control was adopted, which could suppress the wind power generator current harmonic. A harmonic suppression strategy considering the neutral point voltage balance was proposed. The three-level and two-level converter direct drive permanent magnet wind power generation system was compared. The results show that the three-level topology can effectively restrain the harmonic current of generator in different speeds and loads, and can improve the efficiency of the system.更多还原