What is the purpose of the frequency converter in a Dfig generator wind turbine?

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 the use of converter in wind turbine?

A power electronic converter enables efficient conversion of the variable frequency output of an induction generator, driven by a variable speed wind turbine, to a fixed frequency appropriate for the grid or a load.

What is advantage of doubly-fed induction generator?

The primary advantage of doubly-fed induction generators when used in wind turbines is that they allow the amplitude and frequency of their output voltages to be maintained at a constant value, no matter the speed of the wind blowing on the wind turbine rotor.

What is Dfig generator?

The DF generator (DFIG) 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.

How does Dfig work in wind turbines?

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 a wind converter?

3.1 Introduction. Wind energy conversion systems (WECS) are designed to convert the energy of wind movement into mechanical power. With wind turbine generators, this mechanical energy is converted into electricity and in windmills this energy is used to do work such as pumping water, mill grains, or drive machinery.

What are the advantages and disadvantages of wind energy conversion?

It is available free and is inexhaustible. It is clean and Non-Polluting. Have low maintenance cost. Has low cost of power generation of about Rs.

What are the advantages of large DFIG wind turbines?

Since it can operate as synchronous generator, a major advantage of large DFIG wind turbines is that they can contribute to the system’s stability after a fault occurs. However, this relies heavily on the control options given by the power converter.

Why do wind turbines need a ‘full converter’?

Synchronous generators operating with variable speed require a ‘full converter’, necessary for converting power generated with continuously changing frequency into grid-compliant power for feeding into the grid network. Indian supplier Kenersys applies a synchronous generator with external field excitation in its 2 and 2.5 MW wind turbine models.

Why choose a power converter for DFIG rotor?

DFIG can be accurately controlled due to the fact that the power converter can adjust both the magnitude and phase of the voltage applied to the rotor.

How does a synchronous generator work with a DFIG?

It actually forms an AC excitation with a variable frequency, just like the DC excitation used in synchronous generators. This operation gives the DFIG the benefits of a synchronous generator. These benefits include the separate control of reactive and active power, or the control of the wind turbines power factor.