Amplitude-Phase-Locked-Loop-Based Power Injection Strategy for Wind Power Generation Under Three-Phase Grid Fault

This article proposes an active and reactive power injection strategy based on the amplitude-phase-locked-loop (<italic>APLL</italic>) to improve the transient performance of wind power generation (WPG) systems during fault ride through (FRT). The dynamic characteristics of the <italic>APLL</italic> can autonomously reflect the required active and reactive power of grid. The dynamic signals (<italic>df/dt</italic> and Δ<italic>V</italic>, <italic>dV/dt</italic>) of <italic>APLL</italic> are used to produce active and reactive power references of WPGs, respectively. Based on the proposed strategy, wind turbines (WTs) can spontaneously provide dynamic active and reactive power support for the grid without control switching from the normal condition to the FRT condition. Moreover, the spontaneous active and reactive powers support based on the <italic>APLL</italic> is able to alleviate the transient over-voltage and reduce the power-angle swing to enhance the transient performance at sending and receiving areas. Simulations based on a 2-area power system are implemented to verify the effectiveness of the proposed strategy.