Stability of grid-connected permanent magnet synchronous generator-based wind turbines

This work studies the stability of a wind turbine with permanent magnet synchronous generator (PMSG) for wind energy conversion systems (WECSs) integrated to power grids using a proposed control strategy. The cascaded control structure uses PI controllers and feedback linearisation which takes the nonlinear relationship between the generator speed and DC-link voltage into account. The stability analysis given here concentrates on the small signal model and utilises eigenvalue analysis to achieve a result. The relation between different modes and state variables is determined by calculating participation factors, based on which effective controller parameters can be selected to improve control performance. Achievable performance is illustrated on numerical simulations performed on a 2MW PMSG WECS model.