Modelling and Simulation of a Full Power Conversion Wind Power System Based on Inertial Self-synchronization

Aiming at the lack of frequency support capability of conventional wind turbines and the stability problem under weak grid, this paper gives a voltage source control strategy for full-power wind turbines. The grid-side converter adopts the principle of virtual self-synchronization to achieve grid-connection without phase-locked loop, and the machine side adopts the optimal speed to formulate the control strategy, while the bus voltage control strategy is added to achieve the deep coupling between the machine side and the grid side and the inertia transfer function provided. Under the described control strategy, the full-power wind turbine can provide significant inertia response. The article carries out a stability analysis of the system based on the Nyquist criterion of the open-loop transfer function. Finally, a full DC wind farm simulation example is constructed by PSCAD/EMTDC simulation software to verify the effectiveness of the proposed control method and the correctness of the theoretical analysis.