Wind Presentation 1

8/8/2019 Wind Presentation 1

http://slidepdf.com/reader/full/wind-presentation-1 1/22

Mechanical Control of

Wind Turbine

Payal Gupta

Advisor: Dr. Ovidiu Crisan



Contents

Objective Structure of wind turbine

Predicting Power Output

Calculation of Wind Power Limitations on Power Output of Wind

Turbine

Control on Wind Turbine Future Work

References



Objective

To develop control system to enable the better use of turbine capacity along with relieving the aerodynamic

and mechanical loads that reduces the life of the

turbine.To improve the power quality so as to properly

integrate with the network with no adverse effect.

The main control goal for scheme design is to

maximize the energy capture taking account of safe

operation restriction like rated power, rated speed and

cut-out wind speed, etc.



Orientation

Horizontal Axis WindTurbine Vertical Axis WindTurbine



Structure Of Wind Turbine





Drive Train 3MW



Connection of Wind Farm to Power

System



Rotor Solidity

Solidity is the ratio of total rotor platformarea to total swept area

Low solidity (0.10) = high speed, low torque

High solidity (>0.80) = low speed, high torque

A

R

a

Solidity = 3a/A



Predicting Power Output

eWind Day-Ahead Hourly Forecast

0

20

40

60

80

100

120

140

2/5 2/6 2/7 2/8 2/9 2/10 2/11

Date

P o w e r O u t p u t ( M W

Reported eWind Forecast



Turbine Power Limited By

Power in the wind

Betz limit (air can not be slowed to zero)

Low speed losses - wake rotation

Drag losses ± aerodynamics and blade

geometry

Generator and drivetrain inefficiencies



Betz LimitAll wind power cannot be

captured by rotor or airwould be completely still

behind rotor and not allow

more wind to pass through.

Theoretical limit of rotorefficiency is 59%

Most modern wind turbines

are in the 35 ² 45% range



Lift & Drag Forces

y The Lift Force is perpendicularto the direction of motion. We

want to make this force BIG.

y The Drag Force is parallel to thedirection of motion. We wantto make this force small.

= low

= medium<10 degrees

= HighStall!!



Tip-Speed Ratio

Tip-speed ratio is the ratio of the speed of the rotating blade tip to the speed of the free stream wind.

There is an optimum angle of attackwhich creates the highest lift to dragratio.

Because angle of attack is dependant onwind speed, there is an optimum tip-speed ratio

R

V

TSR =Where,

= rotational speed in radians /sec

R = Rotor Radius

V = Wind ³Free Stream´ Velocity

R

R



Calculation of Wind Power

Effect of swept area, A= R2

Effect of wind speed, V

Effect of air density, V

R

Power in the Wind = ½AV3

GeneratorTorque; c = K.2

Cp(*,*)



Performance Over Range of Tip Speed

Ratios

Power Coefficient Varies with Tip Speed Ratio

Characterized by Cp vs Tip Speed Ratio Curve

0.4

0.3

0.2

0.1

0.0

Cp

121086420

Tip Speed Ratio



Energy Production Terms

Power in the Wind =

1/2 V AV3

Betz Limit - 59% Max

Power Coefficient - Cp

Rated Power ± Maximum

power generator canproduce.

Capacity factor

± Actual energy/maximum

energy

Cut-in wind speed whereenergy production begins

Cut-out wind speed where

energy production ends.

Typical Power Curve



Wind Turbine Control

Control of

the power of

a wind

turbine

Stall control

Pitch control

Yaw Control



Pitch Control vs. Stall Control

y Pitch Controly

Blades rotate out of the windwhen wind speed becomes toogreat

y Stall Controly Blades are at a fixed pitch that

starts to stall when wind speed istoo great

y

Pitch can be adjusted forparticular location·s wind regime

y Active Stall Controly Many larger turbines today have

active pitch control that turns the blades towards stall when windspeeds are too great

P itch angle, , ² The rotation angle of thewhole blade measured from the plane of rotation from the tip chord line.



Turbine Control Block Diagram



References

´WindTurbineµ,

http://en.wikipedia.org/wiki/Wind_turbine.

Fernando D. Bianchi,Hernan De Battista and Ricardo J.

Mantz, ´WindTurbine Control Systems -Principles,Modeling and Gain Scheduling Designµ, Springer-

Verlag London Limited 2007.

´Vestas -V 90 3.0 MWµ,

http://www.vestas.com/en/media/brochures.aspx. Jason H. Laks, Lucy Y. Pao, and Alan D. Wright,

´Control of WindTurbines: Past, Present, and Futureµ



The Kidwind Project

www.kidwind.org

Thank You

Documents

Wind Presentation 1