Wind Turbine Design and Implementation.

Team MembersMembers:

Luke DonneyLindsay ShortNick RiesDario VazquezChris Loots

Advisor:Dr. Venkataramana Ajjarapu

Client:Dr. Dionysios Aliprantis

Our ProjectPurpose: Create a wind turbine that will be

installed on the roof of Coover Hall on the Iowa State University campus.

The turbine will supply approximately 500-1000 W of power to the Coover power grid.

The turbine will only generate power when the wind speed is high enough for the gears to turn at the rated speed of the generator.

Proposed SolutionFixed speed, upwind,

AC turbine facing west for maximum wind power

Tower height - 6 m (20 ft)

Optional: connection to PC located inside Coover Hall to display power output and other data

Image from http://www.daviddarling.info/encyclopedia/B/AE_blades.html

Operating EnvironmentThe turbine will function outdoors on top of

the Coover hall roof. It will be subjected to every sort of weather including rain, extreme wind, snow, ice, and lightning

www.eng.iastate.edu/tour/images/coover1.jpg

Concept Sketch

System DescriptionProcess starts with energy collection from

the wind via the turbine.The mechanical energy is transferred

through the gearbox to the generator, where it is converted to electrical power.

The power is fed directly into the Coover grid at 3-phase, 60 Hz.

System Block Diagram

Blades and GearboxBlades shall be in the area of 4.5 feet in radius,

and will be designed by a manufacturer.

Gearbox shall be rated at 9:1 and shall have the appropriate strength to deal with torque generated.

http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt_wind/images/wind1_en_1371.gif

Blade CalculationsAvailable power in wind: P = 1 kWAverage wind speed (Ames, IA): v = 14 mph

(6.25 m/s)Air density: ρ = 1.222 kg/m3 Area = πr2

Using this information, we find:3

2

1AvP 32 25.6222.1

2

11000 r

703.62 r 13.22 r ftmr 79.446.1

TowerKurtis Stockton designed the tower.

Note that the actual turbine blades donot look like the ones in this model.

Gearbox CalculationsOptimum Tip Speed Ratio (TSR) for 3 blade

turbines: 6Start up wind speed (Ames, IA) at 10 mph (4.47

m/s)Blade length at 4.5 ft (1.37 m)Generator Rated at 1725 rpm

Using this information, we find:

GearboxMichael Renoe and ateam of his fellowmechanical engineersdesigned the gearbox.

Note that the actualturbine blades do notlook like the onesin this model.

AC Generator

• 2 Hp• 3 Phase• 60 Hz• 1725 rpm

• 208-230 Vline-line

• 6.5 Afull load

Controls – OverviewAtmel microcontroller controls components.Anemometer serves as wind speed detector.Speed sensor on gearbox measures rotation

speed of the turbine.DC relay releases brake on turbine.AC relay connects the generator output to

the grid.

Controls – ConsiderationsAtmel ATtiny85 microcontroller was selected

because it is automotive-grade. It operates in temperatures from -40° C to 125° C.

All electrical components were chosen to operate at least in the range of -10° C to 60° C.

For safety reasons, brake is applied by default and grid connection is disconnected by default.

By waiting until generator is spinning at optimal speed before connecting to grid, a startup current surge is eliminated.

Controls – FunctionalityWhen the cut-in wind speed is reached, brake

is released and turbine allowed to spin up.When turbine has reached optimal speed, it

is connected to the grid to generate power.When the cut-off wind speed is reached,

brake is activated and generator disconnected from the grid.

If electrical power is lost, brake is automatically applied and generator is automatically disconnected from grid.

Controls – Input/OutputInputs Specifications Details

Anemometer

Turbine Speed Sensor

Outputs Specifications DetailsDC Relay (Brake) requires 12 VDC at 150 mA output releases brakeAC Relay (Grid Connection) requires 12 VDC at 170 mA output connects turbine to grid

outputs ground once for every 2.5 MPH of wind speed

input is from reed switch, which is activated by magnet on shaft

outputs ground once for every revolution of the turbine

input is from reed switch, which is activated by magnet on shaft

Controls – Schematic

Controls – Circuit Layout

DeliverablesWind Turbine and Mounting TowerPower and Control SystemsUser’s Manual

www.jupiterimages.com

Users and UsesIowa State Electrical and Computer

Engineering faculty and studentsResearch purposes and classesThe connection to PC for display may show

extra information such as the wind speed, graphs of power output over time

Work BreakdownID Task Nam e

1 Project Reporting

2 Project Plan

3 Website

4 Draft Design

5 Draft Report

6 Bound Report

7 Project Pos ter

8

9 Problem Definition

10 Safety Considerations

11 Determ ine Turbine Type

12 Determ ine Load for Turbine

13

14 Project Design

15 Des ign Turbine Size

16 Define Sys tem Layout

17 Des ign Power Electronics

18 Des ign Control Electronics

19 Obtain Funding/Donations

20 Determ ine Turbine Mounting

21 Small-scale Model

22 Sim ulation

2/3 2/10 2/17 2/24 3/2 3/9 3/16 3/23 3/30 4/6 4/13 4/20 4/27 5/4 7/13January 21 February 11 March 1 March 21 April 11 May 1

Assumptions and LimitationsAssumptions:

Funded by group budget and outside resources

Similar wind turbine designs are currently being used

Limitations:Turbine height and weight

must be fit for Iowa State and City of Ames building regulations

Turbine must not interfere with other objects on Coover hall roof

Turbine can only output as much power as there is wind to supply it

Coover Hall is currently under construction and might interfere with its placement

Funding is limited

Estimated Project CostItem Description Estimated Price

Anemometer one pulse per rotation $49.00AC Relay 25A @ 220VAC, 4PST, 12VDC @ 167mA coil $63.00Blades 3 Whisper 200, 9' diameter $177.00AC Electric Motor 2HP, 3PH, 1725 RPM, 60Hz $428.00Atmel ATtiny85 8-pin DIP, 10MHz $3.00Signal Diodes $0.04 x 2 diodes, 1N4148, 100V, 200mA $0.08AC to DC Adapter Output: 12V @ 5A $30.07Voltage Regulator L7805AB 5V, 1A $0.99Resistors $0.03 x 2 resistors, 1/4W, 10KOhm $0.06Capacitor $0.24 x 2 Capacitors, 10uF, 25V $0.48Reed Switch SPST-NO for speed sensor, use with magnet $0.81Magnet for use with Reed Switch $1.63Enclosure ABS Plastic, Watertight, 9.6”x6.4”x3.6” $45.16Circuit Board 3 boards 2.5”x3.8” $51.00Transistors $0.19 x 2, NPN, 200mA, 15V $0.38Circuit Breaker 20/30 Amp, 4-pole $20.00Cable-Communications 100' $10.00Cable-Power 150', 600V, 3-Conductor $100.00Cable-Ground 50', 1/c 2/0 $25.00Conduit 2" $50.00Terminations $10.00Steel Cable 110' $100.00Steel Pole Schedule 160, 2.5” dia., 20 ft. $20.00Hub $20.00Brake $50.00Gearbox 9:1 ratio $900.00Miscelaneous $100.00

TOTAL $2,255.66

 

  

 

Estimated Personnel Effort

RisksRisks:

1. Team member leaves project due to illness, co-op,… etc.

2. High winds could damage blades, throw turbine off roof

3. Lightning could strike turbine

4. Ice could freeze up the turbine

5. Birds could fly into turbine

Risk Management:1. More than one person

assigned to each task2. Brake system will stop

rotor in high winds and will be bolted into roof to prevent it from blowing off

3. Install lightning rod near turbine and possibly ground blades to prevent damage to system

4. Heat tracing on moving parts to prevent ice buildup or keep turbine close to rooftop for easy maintenance.

5. Speakers to play sounds to keep crows away.

Issues Not enough funding Brake not finalized Mounting for turbine onto tower not finalized Gearbox too expensive

Questions?