The doubly-fed induction generator (DFIG) with the back-to-back converter is a system frequently used in wind turbines. Traditional wind turbines have fixed turning speeds, while DFIG enables wind turbines to operate with various range of speeds.
How does a turbine work simple?
Wind turbines work on a simple principle: instead of using electricity to make wind—like a fan—wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.
What are the advantages of Pmsg?
PMSG also has advantages of high efficiency and reliability, since external excitation and conductor losses are removed from the rotor. To supply the grid with active power at fixed voltage and frequency, the PMSG is connected to grid via a line power converter.
How does a Dfig generator work?
The principle of the DFIG is that stator windings are connected to the grid and rotor winding are connected to the converter via slip rings and back-to-back voltage source converter that controls both the rotor and the grid currents. Thus rotor frequency can freely differ from the grid frequency (50 or 60 Hz).
What is doubly-fed induction generator?
The doubly-fed induction generator (DFIG) system is a popular system in which the power electronic interface controls the rotor currents to achieve the variable speed necessary for maximum energy capture in variable winds.
What is an advantage of using a double wound induction machine in a wind turbine?
Using a DFIG in wind turbines offers the same advantages as when a synchronous generator is used as a variable speed generator. Both types of schemes require two AC/DC converters. But, the two converters in DFIGs are much smaller than those in synchronous generators of similar output power.
Why is doubly-fed induction generator used in wind turbines?
Traditional wind turbines have fixed turning speeds, while DFIG enables wind turbines to operate with various range of speeds. The back-to-back converter is connected to the rotor of the DFIG, and its purpose is to feed the rotor with currents of varying frequency, in order to reach the desired rotor speeds.
What is one of the main disadvantages of asynchronous generator use in a wind turbine?
Asynchronous (Induction) Generator. Disadvantages: It has to receive an exciting current from another source and consumes reactive power (so, reactive power is supplied by the grid or by a power electronic system).9 Jul 2010
Why Dfig is called doubly-fed?
A Doubly Fed Induction generator as its name suggests is a 3 phase induction generator where both the rotor and stator windings are fed with 3 phase AC signal. It also consists of a multiphase slip ring assembly to transfer power to the rotor. It is typically used to generate electricity in wind turbine generators.