采用双馈机组的风电场无功功率控制研究

Reactive power control research of wind farm adopting doubly-fed induction generators

现今双馈风力发电机已成为风力发电的主流机型,然而在故障期间,转子侧变流器在转子保护的作用下退出运行,不能向电网提供无功功率以保持系统稳定运行。分析了网侧变流器的无功调节能力,提出了电压外环和功率外环两种控制模型。在DIgSILENT/Power Factory仿真软件中建立了包含风电场的三机九节点系统,仿真结果表明在故障情况下,与传统的单位功率因数控制相比,两种控制模型下的网侧变流器均能产生较多的无功,在一定程度上提高了风电接入系统的暂态电压稳定性。最后对比分析了网侧变流器采用两种控制模型时的无功特性。

Doubly fed induction generator has become the mainstream model of the modem wind power, however, during the fault, the rotor-side converter is out of operation under the action of the rotor protection, and cannot provide reactive power to the grid to maintain the stability of the system. This paper analyzes the reactive power regulation capability of grid side converter, proposes two control modes of voltage outer loop and power outer loop and constructs three-machine nine-bus system containing wind farm. Simulation results show that grid side converter can produce more reactive power under two control modes compared with the traditional unity power factor control under fault condition, and can improve the system transient voltage stability to a certain extent. Finally it compares and analyzes the reactive characteristics of the grid side converter with two control modes.