Investigating the transient responses of fully rated converter-based wind turbines

Large penetration of wind power has forced transmission system operators (TSOs) to set stringent grid codes that require wind farms to ride through faults and support the stability of the adjacent network. Theoretically, full converter based wind turbine can ride through any (symmetrical or unsymmetrical) grid faults as the generator is fully decoupled from the grid through the grid side inverter. However, the power converter performance, in practice, is severely affected by network faults and by the wind gusts. This paper investigates the transient responses of wind generators under reactive power control, wind gust and symmetrical and asymmetrical voltage sags. The impacts of voltage sags on d-q control conditions of the converters will also be taken into account. The typical vector based PI controller is applied to control the generator and the grid side converter. Simulation studies are conducted for 5 × 2 MW wind farms using MATLAB/SIMULINK.