A Wind Farm Model Including the LVRT Controller Using Vector Variable

The low-voltage ride-through (LVRT) is the ability of wind turbines to stay in grid. As wind generation grows, dynamics of wind farms under fault will have a greater impact on the power system. Thus, the LVRT process must be considered. Different from that of a single wind turbine, the wind farm's LVRT dynamic is the combined effect of all wind turbines. To accurately simulate the LVRT process, it is necessary to reflect each individual wind turbine's dynamics. Due to the large number of devices involved, a method for modeling wind farms considering LVRT process and related controller is proposed in this paper. A doubly-fed induction generator (DFIG) usually includes the crowbar and switching control strategies to satisfy the LVRT requirements, these components are considered in detail in this work. With the proposed method, LVRT process of the whole wind farm throughout the fault and the post-fault stage can be captured. Meanwhile, all wind turbines can be modeled with one submodule with vector variables using this method instead of modeling them one by one. It decreases the simulation time and modeling effort. The validity of the vector model is verified by comparing the Simscape model's simulation results. Time-domain simulation shows that this vector modeling method can conserve the LVRT dynamic of all wind turbines located within the wind farm.