Wind Turbine Generators

In recent years, the power generation from wind source is increased rapidly in power systems. In wind source-based power generation, there are different types of wind turbine (WT) models used for power generation which have different topologies. The type-1 and type-2 wind turbines use induction generators (IG). The type-3 wind turbine use doubly fed induction generators (DFIG) with power converters (33% of wind turbine rated power) which provides variable speed operations (speed range is ±33% with synchronous speed). The type-4 wind turbine uses permanent magnet synchronous generators (PMSG) or induction generators. Type-4 wind turbine generator is fully decoupled from the grid through back-to-back power converters, and it can be operated with a wide range of speed variations.

The type-3 and type-4 wind turbine generators are modeled with power converters that provide variable wind speed operation, independent real and reactive power control, and low voltage ride-through (LVRT) operation set by the grid code regulators. Considering these advantages, large-scale (MW level) wind power generation uses type-3 and type-4 wind turbine generators. If wind power contribution is more than 40% of total capacity, then it can be considered a high level of penetration into the grid.

References

• Walling, R. A., Ekrem Gursoy, and Bruce English. "Current contributions from Type 3 and Type 4 wind turbine generators during faults." In PES T&D 2012, pp. 1-6. IEEE, 2012.