Yin Jun, Qian Weichen, Huang Xiaobo
School of Electrical Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China.
Sensors (Basel). 2023 Oct 10;23(20):8372. doi: 10.3390/s23208372.
The transient characteristics of wind farms in groups are quite different; in addition, there is a strong coupling between the wind farms and the grid, and these factors make the fault analysis of the grid with wind farm groups complicated. In order to solve this problem, a mathematical model of the converter is established based on the input-output external characteristics of the converter, and a transient model of a doubly fed wind turbine (DFIG) is presented considering the influence of the low-voltage ride-through control (LVRT) of the converter, and the effect mechanism of the LVRT strategy on the short-circuit current is analyzed. Finally, a short-circuit current calculation model of a doubly fed wind turbine with low-voltage crossing control is established. The interaction mechanism between wind farms during the fault is analyzed, and a short-circuit current calculation method of doubly fed wind farm groups is proposed. RTDS is used to verify the accuracy of the proposed short-circuit current calculation method for doubly fed field groups. On this basis, a method of power grid fault analysis after doubly fed field group access is discussed and analyzed.
风电场群的暂态特性差异较大；此外，风电场与电网之间存在较强的耦合，这些因素使得含风电场群的电网故障分析变得复杂。为解决这一问题，基于变流器的输入输出外特性建立了变流器的数学模型，提出了考虑变流器低电压穿越控制（LVRT）影响的双馈风力发电机（DFIG）暂态模型，并分析了LVRT策略对短路电流的作用机理。最后，建立了具有低电压穿越控制的双馈风力发电机短路电流计算模型。分析了故障期间风电场群之间的相互作用机理，提出了双馈风电场群短路电流计算方法。利用RTDS验证了所提出的双馈风电场群短路电流计算方法的准确性。在此基础上，对双馈风电场群接入后电网故障分析方法进行了探讨和分析。
