PS 7007 WIND ENERGY CONVERSION SYSTEMS

VENKATA SUBRAMANIAN.M,AP/EEE*

UNIT I INTRODUCTION Components of WECSWECS schemesPower obtained from windsimple momentum theoryPower coefficientSabinins theoryAerodynamics of Wind turbine*

Of all the forces of nature, I should think the wind contains the largest amount of motive power. All the power exerted by all the men, beasts, running-water, and steam, shall not equal the one hundredth part of what is exerted by the blowing of the wind. Quite possibly one of the greatest discoveries, will be the taming and harnessing of it. Abraham Lincoln - 1860

Among renewable energy sources, wind energy generation has been noted as the most rapidly growing technology because it is one of the most cost effective and environmental friendly means to generate electricity from renewable sources.

FUNDAMENTAL CONCEPT

Wind energy conversion systems convert the kinetic energy of the wind into electricity or other forms Of energy.flow diagram of the wind energy conversion system.

There are huge variations in size, but all wind turbines from the smallest to the largest work in the same way. The overall configuration is identical. Each system consists of a rotor (blades) that converts the winds energy into rotational shaft energy, a nacelle (enclosure) containing a drive train, and a generator .The energy that moves the wind (kinetic energy) moves the blades.This energy in turn moves the drive train (mechanical energy) is then turned into electricity (electrical energy) in the generators and then stored in batteries or transferred to home power grids or utility companies for use in the usual way.

COMPONENTS OF A WIND TURBINE SYSTEMTypical wind turbines involve a set of rotor blades (usually three) rotating around a hub. The hub is connected to a gearbox and a generator, located inside the nacelle, which houses the electrical components.The basic components of a wind turbine system are shown below and outlined

Rotor power

Ideal (Betz limit)

(wind velocity slows by 2/3)

V1V2*

Horizontal axis Horizontal axis Vertical axis 3-bladed 2-bladed( HAWT )( VAWT )*

Rotor main shaftPitch driveHubMain bearingTop box:low voltage, controlGeneratorBed FrameYaw drivesHigh-speed couplingGearboxWind SensorsGE 1.5 wind turbine52 metric ton nacelle35 metric ton rotorPitch bearingMechanical brakeYaw bearing*

***Each rotor blade can be turned using the pitch drive. The drive train of the WTGS consists of the hub, the rotor shaft, the gearbox, the coupling, and the generator. This is mounted on the ground frame. The rotor shaft is mounted in the main bearing. The gearbox and the generator are noise decoupled to minimized the transmission of noise into the tower. The gear oil is cooled using the oil cooler above a particular temperature. The generator is cool with the chiller above it. In the so-called "top box" there is a small portion of the control system. The yaw drives are used to turn the WTGS into the direction of the wind.