What is doubly-fed induction generator?

What is doubly-fed induction generator?

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.

How does a doubly-fed induction generator work?

When a doubly-fed induction generator is used to produce power at the ac power network voltage and frequency, any deviation of the generator rotor speed from the synchronous speed is compensated by adjusting the frequency of the ac currents fed into the generator rotor windings so that the frequency of the voltage …

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’s the advantages of doubly fed induction generator?

The DFIG provides a huge possibility to improve network dynamic behavior by using the power electronic converters with sufficient control arrangements. Many different structure and control algorithms can be used for control of power converter.

Why is it called doubly fed induction generator?

Instead of the usual field winding fed with DC, and an armature winding where the generated electricity comes out, there are two three-phase windings, one stationary and one rotating, both separately connected to equipment outside the generator. Thus, the term doubly fed is used for this kind of machines.

What are the advantages of double feed induction generator DFIG based wind turbine system over the conventional wind generation system?

Recently doubly fed induction generator (DFIG) becomes more popular in wind power due to its various advantages over other types of wind turbines, such as variable speed, lower power electronic cost and so on [7].

How does a permanent magnet synchronous generator work?

Working Principle of Permanent Magnet Synchronous Generator The working of the PMSG depends on the field produced by the permanent magnet attached at the rotor of the generator for the conversion of mechanical energy into electrical energy. These blades rotate the rotor for the production of electrical energy.

What’s the advantages of doubly-fed induction generator?

What is the difference between synchronous and induction generator?

An induction generator produces electrical power when its rotor is turned faster than the synchronous speed. The motor normally turns slightly slower than the synchronous speed; the difference between synchronous and operating speed is called “slip” and is usually expressed as per cent of the synchronous speed.

What is the purpose of permanent magnet generator?

A permanent magnet generator is a device that converts mechanical energy to electrical energy. In this device the rotor windings have been replaced with permanent magnets. These devices do not require a separate DC supply for the excitation circuit or do they have slip rings and contact brushes.

Can a permanent magnet motor be used as a generator?

Permanent magnet direct current (DC) machines can be used as either conventional motors or as DC wind turbine generators as constructionally there is no basic difference between the two. Generally with conventional DC machines, the field winding is on the stator and the armature winding is on the rotor.