Wind turbine alternator AMK

three-phaseinduction4-pole

Doubly-fed generators The mainstream DF concept, using a standard high speed drivetrain, enables small generator size. It offers high system efficiency at nominal speed, because only a small converter (1/3 Pn) is needed for this semi variable speed operation concept. The system also satisfies the basic grid code requirements. ABB has delivered several types of DFIG (doubly fed induction generator) designs to leading turbine manufacturers since 1997. Benefits: Proven reliability - maximized profitability ■ Rotor with high overspeed withstand ■ Insulation against converter voltage peaks ■ Slip ring design for long service intervals ■ Bearing design avoiding circulating currents Low cost of ownership (purchase - running - downtime) ■ Globally identical manufacturing ■ High availability and > 97 % efficiency ■ Easy serviceability and local support The DF generator (DFIG) is an asynchronous wound rotor slip ring machine where the rotor windings are connected to a converter via slip rings and brushes. The generator feeds power both from the stator and from the rotor. The doubly-fed converter (1/3 Pn) is smaller compared to a full converter, however even with this smaller converter the generator speed, power and power factor can be controlled to reach power yield with low LCoE. The doubly-fed concept has ability to feed reactive power to support the grid and satisfy basic grid code requirements.