WIND ENERGY

Wind Turbine Technology



Wind Turbine Technology

Introduction

Wind turbine generation plants are an important technology for the large scale wind generation. The large plants have been already installed in European countries. There are several challenges in the way to get benefits from wind energy related to the basic principles on which wind power generation depends, the operation and maintenance of the plants, area for the plant installation, technical performance of the plant related to the location area, the impacts on the electrical network and effects on the health and safety (Breeze, 2005).

Basic principles

Shape of Machine

The basic wind turbine can be constructed in several different shapes, most of the large wind turbines that are designed for commercial use, resemble the shape of an airplane, which is mounted from a top to a tall tower. This turbine uses the three blades and a rotor that spins horizontally about an axis (Gipe, 2004).

Speed of Machine

Typical turbine starts to rotate in wind of about 4 m/s and continue to coast in the lower wind of about 3 m/s. The Wind turbines can produce electricity in the wind of 4.5m/s up to 25 m/s. The windy site helps the wind turbines to operate about 2/3 times of 6,000 hrs/ yr. At the high windy sites, as the turbine excess the wind of 25 m/s it stops automatically by pitching the blades that slows down the rotors. It keeps on slowing down the rotor until a parking brake is applied to completely bring the rotor at halt. The rotor often does not brake to stop the machine but it keeps on spinning slowly while, not even generating electricity. Thus, it keeps bearings of the rotor lubricated. The wind capacity are estimated or mapped by geographical regions analyzing the data related to wind speed available at the place. Regions are assessed for the following factors to collect the data (Gipe, 2004).

1.The location of the proposed land area must have the good wing resource.

2.The speed of wind, which means the allocation of a single speed node for each region.

3.Elevation

4.Types of Terrain

Size of Machines

The Wind turbines are built in a wide range of sizes. The smallest turbines are used to charge the batteries on sailboats that use the rotors with a diameter less than 1 meter while the household size turbines are larger which have rotors of diameter 3 to 15metres. The weight of this rotor is less than 50kg to 1000kg. The wind turbines of commercial size are larger as 80 to 100metres (Gipe, 2004).

Generator Variations

The typical wind turbines use the gearbox or the transmission for increasing speed of the rotor as the generator required. Some turbines that do not use gearbox where the generator is drive by the rotor directly (Rivkin, 2012). 

Towers

The Wind turbines are installed as guyed and unguyed towers. The large wind turbines are installed on the unguyed towers because of their size, whereas turbines with smaller and medium sizes are installed on the guyed towers. The large turbines either use a tubular tower of ...