DFIG Based Wind Power Generation System: Problem Formulation (Research Paper Sample)

DFIG based Wind Turbines
[Name]
[Institutional Affiliation]
DFID based Wind Turbines
Section 1: Problem Formulation
* Background
The wind energy is regarded as one of the most cleanest and reliable sources of energy on the planet and has received a lot of attention in the past decade. The costs for the conventional sources of energy dependent on the fossil fuels is increasing with the passing time with their adverse impacts on the environment. Among many sources of the green power the wind energy has become one of the most reliable source of energy (Sharma, Mishra, & Datta, 2015). Across, the world the electrical energy produced by the electrical energy has surpassed the level of Giga Watt and large wind farms are planned and implemented in most parts of the world.
The main components of a conventional WPGS (Wind Power Generation System) consist or a turbine rotor, generator, gearbox, transformer, and other power electronic devices. The turbine rotor is responsible for converting the conventional mechanical wind power into mechanical energy which is used to run the turbine and attached generators to produce the electricity (Sharma, Mishra, & Datta, 2015). The wind turbines are able to capture the wind power using blades which are aerodynamically designed to capture the maximum power to be converted into the electricity. Generally, the rotating speed of the blades decrease by increasing the number of blades in a turbine. A turbine able to generate the power in the megawatt region must rotate with a minimum speed 15-20 rpm (Sharma, Mishra, & Datta, 2015). Most of the wind farms in the world are connected to medium power grids, while there are some farms which are connected to large Giga Watt farms.
Recently, the doubly fed induction generators (DFIG) have been introduced in the field of wind power generations. These generators are commonly referred to as (DFIG-WT) generators. The primary purpose of these generators is to generate maximum electrical energy, increase the controllability of the generators, and reduce the capacity and costs of the power electronic devices used at the generation farm. The stator circuit of the DFIG generator is connected directly with the gird while the rotor circuit is directly powered via back to back power converter (Sharma, Mishra, & Datta, 2015). The back-to-back converters are consisted of two converters, one is connected directly with the grid while other is connected with the rotor, and the both generators are connected to each other using back-to-back connection. There is a capacitor placed between the link of these two rotors which is used to secure the circuit and keep the ripple under check.
* Problem Statement
The wind turbine have been designed to produce the electrical energy in the most cost effective manner. They are generally designed to generate the maximum power output at the speeds of 15 m/s. In the case of energies greater than 15 m/s the system should be able to part the excess energy from the desired to save the damage of the turbine. The wind turbines are therefore designed to have some sort of power control (Sharma, Mishra, & Datta, 2015). The standard control implement in the wind turbines makes it possible for the turbine to operate at peak of CP curve. The equation governing the control can be given by:
Tref=kω2
In the above equation,
k=12πρR5Cpmaxλopt3………………1
However, there is a significant problem associated with this conventional control mechanism. The varying wind forces compel the turbine to operate at different speeds and sometimes the turbines are required to operate at the wind speeds greater than Cp curves. These operational speeds result in the high-mechanical stress on the equipment and thus they transfer aerodynamic fluctuations in the generation system. The DFI...