电网谐波条件下双馈感应风力发电机的建模与控制

从电网谐波条件下双馈感应发电机(DFIG)转子侧变流器的控制入手,通过严格的理论推导,构建了正转同步速(dq)+参考坐标系、反转5倍速(dq)5-和正转7倍速(dq)7+参考坐标系下基于定子磁链定向的DFIG数学模型.通过重新定义这种运行条件下的定子有功、无功功率及电磁转矩,分析和解释了它们产生波动的原因;进而提出4个可供选择的控制目标,给出相应的转子基波和谐波电流指令算法,设计了正转(dq)+坐标系下由单比例-积分(PI)调节器和谐振频率为6倍电网频率的单谐振(R)调节器构成的新型PI-R电流控制器,避免了复杂的相序分离处理和相应的时延影响,实现了对转子电流5次、7次谐波分量的动态抑制.对1台2 MW商用DFIG风力发电机组的仿真研究表明,所述控制方法能显著消除电网谐波条件下DFIG运行时瞬时功率的波动和转矩的脉动,验证了所提出的DFIG数学模型的正确性和改进控制方案的有效性.

Modeling and Control of Wind Turbine Driven Doubly-fed Induction Generators Under Harmonic Grid Voltage Conditions

Based on the detailed analysis on the control of rotor side convertor for the doubly-fed induction generator(DFIG) under harmonic grid voltage conditions,this paper presents a precise mathematical model of the DFIG in the stator-flux-oriented fundamental positive reference frame(dq)+,negative 5-order(dq)5-,and positive 7-order reference frames(dq)7+.The reasons of the oscillations in the instantaneous active power,reactive power and electromagnetic torque of the DFIG are analyzed and explained through redef...