Modelling and analysis of DFIG wind turbine system in PSCAD/EMTDC

Wind turbine technology is currently driven by offshore development, which requires more reliable, multi-megawatts turbines. Models with different levels of detail have been continuously explored for years. This paper presents a 4.5MW doubly-fed induction generator wind turbine model established in PSCAD/EMTDC with two control levels, the wind turbine control and the DFIG control. Two converter models, a detailed and a simplified model are discussed. Mathematical representations of the closed-loop control systems are developed and verified against the PSCAD/EMTDC model. Simulation studies show good correspondence between the two results. In addition, the dynamic response of a 2-mass shaft model to a wind step is also simulated to examine the effect of torsional oscillations. This model can be employed to evaluate the control scheme, mechanical and electrical dynamics and the fault ride-through capability.