双馈风机接入对系统极限切除角的影响

风电场的大规模接入对电网暂态稳定性造成的影响不容忽视。以含双馈风电机组的扩展两机系统为例,建立了双馈风机等值模型,将两机系统等值成单机无穷大系统,依据等面积法则详细推导了风电接入后系统极限切除角的解析式,进而定量分析了极限切除角随风电比例、风机并网位置、故障位置和负荷接入位置等4个影响因素的变化趋势,总结出4种影响因素对暂态功角稳定性的影响规律。在BPA和FASTEST中分别建立含双馈风机的扩展双机系统的仿真模型,对理论分析工作的正确性进行了仿真验证。

Impact on Critical Clearing Angle with DoublyFed InductionGenerator Connected to Power System

The impact of largescale access of wind farms on the transient stability of power grids could not be ignored. Taking the extended twomachine system with doublyfed wind turbines as an example, the equivalent model of doublyfed induction generator was established, and the twomachine system could be equivalent to a singlemachine infinity system. Based on the law of equal area, the analytic formula of critical clearing angle of the system was deduced in detail after wind power accessed. The analytic formula was used to quantitatively analyze the variation trends of the critical clearing angle with wind power ratio, wind turbine grid connection position, fault location and load access position. The influence laws of the above four factors on the stability of transient power angle were summarized. The simulation models of the extended twomachine system with doublyfed induction generator was established in BPA and FASTEST, and the accuracy of the theoretical analysis was verified.