Interpreting the short circuit behavior of Type 4 wind turbine generator

With fast increase in wind generation, grid codes are being revised, requiring wind farms to be connected during fault, and supply reactive support. One of the Wind Turbine Generators used to comply with such grid codes is Type 4 — a synchronous machine with converter interface. The short circuit behavior of this generator is dominated by converter controls, and not clearly derived. This paper documents the controls of a Type 4 wind turbine generator, and develops its short circuit model using time domain simulations of this generator using PSCAD.