Investigation of electrical dynamics of DFIG-based wind turbines during severe symmetrical grid voltage dips

Recently, wind power generation has reached a significant penetration levels in some countries. This is the case for instance in Denmark, Spain and Germany. This imposes new challenges to the transmission system operators (TSOs). New grid requirements for wind generation are needed. These requirements stipulate that wind farms should contribute to power system control, much as the conventional power stations and focus on wind farm behaviour in case of grid disturbances. Isolation of wind turbines in case of voltage dips is not allowed anymore as low voltage ride through (LVRT) capability is required. This paper will discuss the dynamic behaviour of DFIG based wind turbine under severe three phase voltage dips without and with the usage of crowbar protection system including simulation results to verify the discussion.