The Analysis of the Transient Synchronization Stability Margin Based on Doubly-Fed Wind Turbine

Stability of wind power is the long-concerned issue especially in the context of high grid-integration level. Different from traditional synchronous generators, the transient synchronization stability of the wind turbine is maintained by the phase-locked loop after being disturbed. This paper mainly discusses the transient stability of the doubly-fed wind turbine. Firstly, according to the principle of doubly-fed wind turbines connected to grid, a doubly-fed wind turbine model under the time scale of transient stability analysis is established. Then, by theoretically analyzing the dynamic process after being disturbed, the acceleration and deceleration area of phase-locked loop analogous to the synchronous generator is proposed. The critical stability region of the system is analyzed, and a calculation method for the transient synchronization stability margin of doubly-fed wind turbines is proposed. Finally, a detailed model of four-machine two-zone system is built on MATLAB/Simulink software, and the correctness of the conclusion is verified by analyzing the influence of key parameters on transient stability.