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-megawatt turbines. Models with different levels of detail have been continuously explored for years. The speaker presents a 4.5-MW doubly-fed induction generator (DFIG) wind turbine model established in the electromagnetic time-domain transient simulation environment PSCAD/EMTDC with two control levels - wind turbine control and 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, the mechanical and electrical dynamics, and the fault ride-through capability.