新型动态电压恢复器在双馈风力发电机中的应用

在不对称电网故障下,采用基于同相位补偿法改进控制策略的新型动态电压恢复器（DVR）,提高双馈风力发电机（DFIG）的低电压穿越能力。通过两个改进的正负序检测器分别对网侧和机侧电压分量进行分解,消除不平衡故障下的负序分量的影响;利用四个PI控制器分别调节每一相序,注入串联电压,保证双馈风力发电机电压可以达到正常值;通过旋转这个串联电压,注入无功功率到电网中,保证系统的稳定运行,仿真结果证明了所提控制策略的有效性。

A new dynamic voltage restorer application in DFIG

To improve Low-Voltage-Ride-Through capacity of DFIG in asymmetric system fault, a new DVR used the improved proposed control strategy based on same phase compensation method. To solve the negative sequence component effected grid side and generator side under the unbalance fault, first, the grid side and generator side component are decomposed through the two improved positive and negative sequence detector respectively, secondly, four PI controller control each phase sequence respectively, to ensure the generator voltage can restore and achieve rating. Finally, through rotating the series voltage to inject reactive power to the grid, to ensure the stable operation of the system. The simulation results showed the effectiveness of the control strategy.