双馈式风力发电机的机电暂态建模

Electromechanical Transient Modeling of Wind Turbines Based on Doubly-fed Induction Generator

建立可用于大型电力系统暂态稳定分析的双馈式风力发电机(doubly-fed induction generator,DFIG)机电暂态模型。详细分析转子侧变流器和撬棒电阻(crowbar)可能的工作模式,提出计及crowbar的转子侧变流器和控制器机电暂态建模方法;根据机电暂态仿真和设备参数的特征,研究网侧变流器和控制器的简化建模方法;建立直流电压动态和卸荷电路(chopper)数学模型。基于大量型式实验数据,研究国产DFIG在低电压穿越过程中crowbar、chopper的控制逻辑和有功、无功功率特殊控制策略。以华锐1.5 MW DFIG机组为例,用电力系统分析综合程序包软件仿真分析3种不同工况下的运行特性。仿真结果与现场实测曲线一致,证明所建模型准确、可靠,可用于分析大规模DFIG风电场接入对电力系统暂态稳定性的影响。

This paper proposed an electromechanical model of the doubly-fed induction generator （DFIG） suitable for bulk system transient stability studies, The suitable model was presented for rotor-side convertor and crowbar, based on the possible operating modes; according to the characteristic of electromechanical transient simulation and physical facilities, the model of grid-side convertor and controller was simplified; the DC-link and chopper were also taken into account; after statistical analysis of mass field data from type test, the low-voltage-ride-through （LVRT） control strategies of crowbar, chopper, and active/reactive power were proposed. Taking Sinovel 1.5 MW DFIO as an example, several simulations were performed in power system analysis software package （PSASP）. Simulation results show that dynamic response of the proposed model is consistent with field data, owing to the reasonability and accuracy of the model. So, it can be used to analyze the impact of grid-connected large-scale DFIG system on security and stability of power grid.