The DF system using a standard high speed drivetrain enables small generator size and high system efficiency at nominal speed, and it satisfies basic grid code requirements. The first ABB DF generator for wind power was launched in 1997.
- Power range from 500 kW - 6 MW
- Operational speed range 1000 - 2000 rpm
- Patented rotor design for max. overspeed of 3000 rpm
- Increased rotor insulation level against converter voltage peaks
- Proven ABB slip ring design
DF system design:
The DF generator is an asynchronous wound rotor slip ring machine where the rotor windings are connected to a small converter via slip rings and brushes. The generator feeds power both from the stator and also from the rotor. A small (1/3 Pn) converter can be used, because a speed range of +/- 30 % is sufficient for wind turbine applications. The converter enables control of the generator speed, power and power factor, thus giving a wider speed range and improving the energy yield and ability to feed reactive power to support the grid. The DF concept therefore represents an economical way of achieving semi-variable speed operation and satisfying basic grid code requirements.
The new ABB family of 1.5 - 2.0 MW DF generators is designed to fit most turbines used today. The standard modular structure - with both air or water cooling - can be modified for different turbine interface connections. The generator features a new patented rotor design for higher overspeed and voltage peak withstand to fit most converter designs used in the markets.
Doubly-fed 1.5 - 2 MW family
Doubly-fed 2.0 MW generator
Doubly-fed 1.7 MW generator
Doubly-fed water cooled generator 4.2 MW
Doubly-fed 1.3 MW generator