Wind Turbine Design and Implementation Phase IIIIowa State UniversityDepartment of Electrical and Computer

Engineering

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DESIGN DOCUMENTProject: SDMAY11-01Members:Andrew NigroShonda ButlerChad HandLuke RupiperRyan Semler

Advisor:Dr. Venkataramana Ajjarapu

DISCLAIMER: This document was developed as a part of the requirements of an Electrical and Computer engineering course at Iowa State University, Ames, Iowa. This document does not constitute a professional engineering design or a professional land surveying document. Although the information is intended to be accurate, the associated students, faculty, and Iowa State University make no claims, promises, or guarantees about the accuracy, completeness, quality, or adequacy of the information. The user of this document shall ensure that any such use does not violate any laws with regard to professional licensing and certification requirements. This use includes any work resulting from this student-prepared document that is required to be under the responsible charge of a licensed engineer or surveyor. This document is copyrighted by the students who produced this document and the associated faculty advisors. No part may be reproduced without the written permission of the Senior Design course coordinator.

Table of Contents

List of Figures 3

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1. Project Overview 41.1. Executive Summary 41.2. Acknowledgement 41.3. Problem Statement 51.4. Operating Environment 51.5. Intended Users and Uses 61.6. Assumptions and Limitations 61.7. Expected End Product and Other Deliverables7

2. Design Requirements 72.1. Functional Requirements 82.2. Non-Functional Requirements 82.3. Technology Requirements 82.4. Design Requirements – Design Constraints8

3. Detailed Design 93.1. Mounting 10-113.2. Sensors 12-143.3. Wind Turbine 153.4. Inverter 153.5. Controller for Turbine Powered Load163.6. Interface 17

4. System and Unit Level Testing Cases 174.1. Motor Control 174.2. Turbine Testing 184.3. Battery Testing 194.4. Inverter Testing 194.5. Load Testing 204.6. Sensor Testing 204.7. Full System Test 20-21

5. Recommended Project Continue 216. Estimated Resources and Schedule 21

6.1. Estimated Resources 21-226.2. Tasks 226.3. Schedule 23-24

7. Closure Material 257.1. Project Team Information 257.2. Closing Summary 26

8. References and Technical Specifications278.1. Technical Specifications 27-318.2. References 31

List of FiguresFigure 1: Full System Block Diagram 9

Image 1: Bowing under Old Platform 10

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Image 2: Turbine Strapped on Old Mount10

Image 3: Conceptual Drawing of New Mount 11Image 4: Partial CAD model 11Image 5: Pin Diagram 12Image 6: Terminal Modes 12Image 7: Reed Sensor operation 13Image 8: Hall Sensor operation 13Image 9: Optical RPM Sensor 13Image 10: Hamlin Hall Sensor 13Image 11: Hamlin Hall Sensor Wire Diagram 13Image 12: Anomemter and Wind Vane 14Image 13: LabVIEW Wind Speed Input Block Diagram

14Image 14: Inverter System 15Image 15: User Interface Display 16Image 16: User Interface Block Diagram 16

Image 17: Inverter Modes 19

Sheet 1: Estimated Individual Team Member Effort 22Sheet 2: Required Resources 22-23Sheet 3: Task Dedications 23Sheet 4: Task Progression 24Sheet 5: Student Contact Information 25

1. Project Overview

The first section of this design document provides an overview of the Wind Turbine Design and Implementation Phase III Project. This section includes the project background, the problem statement, the operating environment, its users and uses, assumptions and limitations, as well as the product deliverables.

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1.1.Executive Summary:

Over the last century electrical needs have been steadily increasing due to population growth and technological and industrial expansion. Growing environmental concerns and the depletion of fossil fuels have influenced the increased production of electricity from renewable resources. Iowa is the second largest producer of wind generated electricity in the United States, and Iowa State University has been taking strong steps to implement new ideas to decrease its environmental impact and increase self -sustainability.

Our senior design team plans to expand and fine tune a previous wind energy project led by Dr. Ajjarapu. The project consists of a wind turbine driven by a three phase motor that is controlled by an external power source. The goal of the project is to accurately simulate wind conditions to the turbine in a controlled environment and monitor voltage, current, power, and speed. As a team, we need to first understand what was designed and built by the previous group. We need to clearly understand how the system is controlled and document all of our progress.The end product will resemble a small scale renewable electrical network. We will simulate wind conditions to our turbine through data we will receive from wind sensors placed outside provided by another senior design group. The power generated from the turbine will charge a bank of batteries. The direct current (DC) will be converted to alternating current (AC) through an inverter. From the inverter, a load consisting of four light bulbs will be powered.

1.2.Acknowledgement:

Professor Ajjarapu – Faculty Advisor – Provides us with advice on project management as well as technical and financial support.

Coover Parts Department – Provides us with hardware support. NI forums – Provide us with hardware support. Brandon Janssen – Worked on previous project team. Brought us up to speed on the

current system. Senior Design Team DEC10-05: Provide us with wind speed data. Leland Harker: Providing us with CAD model of mounting, and fabrication assistance.

1.3.Problem Statement:This project is a continuation of two previous senior design groups. The final implementation of this project is to design a wind turbine electrical generation system and integrate the power generated into the power grid. A wind turbine will be installed on the exterior of Coover Hall.The extension of the project is to be able to receive a wind profile wirelessly from wind sensors placed outside Coover Hall.

This data will be used as an input to our motor controls allowing us to adjust the speed of the motor to simulate changing wind speeds. This will allow us to take a 24 hour wind profile and operate the turbine continuously for a day. Originally the motor speed is adjusted using a

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voltage knob on the interface. The voltage knob changes the voltage being sent from the power supply to the motor therefore changing the speed of the turbine. This does not allow the speed of the turbine to change according to the changing wind speeds.

Another major point of concern is the motor and turbine platforms. Previously the motor and wind turbine were coupled together on separate mounting systems. Issues we experience with this system include bowing wood on the turbine platform, dangerous movement of the wind turbine during simulation, and inaccurate motor to turbine coupling height.

No project documentation was provided to get started on our phase of the project. This caused a lot of initial confusion. There were no wiring diagrams or documentation of how the interface works.

1.4.Operating Environment:

Ideally the wind turbine would be mounted to the roof of a building, such as Coover Hall, and integrated into the power grid at Iowa State. Although this is ideal, it will not be achieved with our senior design group due to budget constraints. Our system will not be intended for outdoor use; instead we are simulating wind conditions in a controlled environment inside a power lab in Coover Hall. However, our system will be able to handle all environmental conditions such as dust, extreme temperatures, rain and other weather elements should future innovations include outdoor implementation. Wind simulation will be achieved using a three-phase AC motor along with sensors to read current and voltage levels as well as rpm measurements. Data will also be provided via wireless signals from wind sensors mounted outside, which will be used to simulate changing wind speeds for pitch control. An interactive graphical user interface (GUI) in LabVIEW will be used during simulations to display readings and measurements sent from the various sensors.

1.5.Intended User(s) and Use(s):

Intended Users:

The simulation environment is intended to be used by students of the Iowa State University Electrical and Computer Engineering department. These students will have at least a high school education and an interest in using wind as a renewable source of energy. Primary users will consist of Dr. Ajjarapu and future senior design projects for its expansion. Secondary users will consist of students viewing the simulation as a display.

Intended Uses:

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This environment will be used to simulate wind energy generation. This simulation is intended to be an educational tool used to study power generation from small wind turbines. Where the turbine will be rotated by a motor at the current wind speeds and charge its battery bank and power a load according to its current generation level. The load is not intended to provide a primary light source for a room and the battery bank is not intended to power any devices other than the simulation environment.

1.6.Assumptions and Limitations:

Assumptions:

The previous group has all equipment in working condition. For example, the coupling has not been damaged in testing.

The LabVIEW interface has been developed and tested to be accurate in displaying voltage, current, power and speed.

The senior design group working on designing the wind sensor will complete their objectives and will actively communicate any issues in receiving data.

The end product will be comparable to a regular connection to a classroom on the I.S.U. grid (120 V AC at 60 Hz).

Limitations:

The budget of $400 leaves little room for any equipment malfunctions so our group must be completely knowledgeable of the system and its mechanical limitations.

The budget does not allow proper funding for field testing the equipment in its intended environment, mounted to the top of Coover Hall.

There is a lack of documentation (schematics, wiring diagrams, and system manual) of the previous group’s work.

Must wait for other senior design group we are working with to finish to begin testing.

1.7. Expected End Product and Other Deliverables

Air Speed Simulation:

We will be expanding on the previous groups control interface to include motor control that will accurately simulate wind speed. This interface will be programmed in LabVIEW and will be used to control and monitor the entire system.

Variable Load:

We will be creating a variable load to connect to our power generation system in order to simulate the system being connected to a real grid. This grid will have voltage and

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current sensors so it can report back to our interface the amount of power being used and the power output can be adjusted accordingly.

Wind Turbine Mount:

A new mounting system will be designed in order to stabilize the system and avoid damage to the turbine and the motor. This will involve a thicker base that will solve the problem of the previous group having the base bow down making the system unbalanced. It will also include a stabilization plate that will decrease the vibrations that the turbine receives from the motor increasing efficiency and avoiding damage to the system.

User Manual/Diagrams/Descriptions:

We will be creating a user manual that will help future groups and other users become acquainted with the setup more quickly. This will save others time and hopefully avoid future mistakes. We will also be creating wiring diagrams and descriptions of system components and functionality.

2. Design Requirements

The following sections describe the specific requirements defined for the project design. All solutions must meet the requirements in this section.

2.1.Functional Requirements

FR01 The turbine will generate a 24V DC output. FR02 The turbine will generate a 400W peak output. FR03 The test-bed connection will serve to simulate the load. FR04 The motor will simulate outdoor wind speed. FR05 The sensors to gather wind data will be an anemometer and wind vane. FR06 The RPM sensor will accurately reflect the speed of the motor within ±5%. FR07 The wind turbine will supply a load after charging the batteries to 23V. FR08 The user interface will display accurate measurements of DC voltage and current,

RPM, and real power produced.

2.2.Non-Functional Requirements:

NFR01 The project will comply with all state and federal electrical regulations. NFR02 The turbine will be remounted to a new stable operating platform. NFR03 The project will be documented through technical manual and in-depth

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schematics. NFR04 Wiring and connections will be redone in a professional manner.

2.3.Technology Requirements:

Motor and turbine must be coupled at proper height. Wind sensor hardware must withstand a temperature range of -30 to 100 degrees Fahrenheit. All sensor equipment must be compatible with DAQ module.

2.4.Design Requirements – Design Constraints: Wind speed signal can be lost. Wind speed can be higher than our simulated limits. Motor will spin while turbine can be braking.

3. Detailed Design

The following section describes in detail the approach we will use to implement our design. This section describes the system mounting, the sensors that we will use the wind turbine, the inverter that will be used, the load controller, and the overall interface.

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Figure 1: Full System Block Diagram

The process of our simulation is to wirelessly receive data from an outdoor wind speed sensor and simulate a wind turbine powering a load from this wind speed. The Wind Sensor Receiver will give the outdoor wind speed and direction. LabVIEW will convert the wind speed to an estimated RPM for the AC motor. The GPIB-USB interfaces LabVIEW and the Kikusui 3 phase Power Source. The AC motor is coupled to the turbine to simulate the blades of the turbine in an outdoor environment. The Wind Turbine’s generated power charges the Battery Bank. The Battery Bank provides DC power the Outback Inverter which converts this to AC power for our AC Load. The sensors provide data to our USB NI DAQ which is displayed in LabVIEW. The LabVIEW interface gives voltage and current data from the sensors, as well as the RPM of the motor.

3.1.Mounting

In order for the wind turbine to be operational indoors it needs to be securely coupled to the motor that will act as the gusting wind input. Since the turbine utilizes a tail that manually moves towards the direction of the wind, the turbine is free to move side to side. When the turbine is coupled to the motor, it would not stay in place. The movement could cause the internal damage to the generator destroying the turbines ability to produce power.

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To solve this issue, the previous group constructed a platform for the turbine to sit and used belt straps to hold the turbine in place. The motor was bolted to its own separate platform and coupled to the turbine. However, when we took over the project the old mount was significantly bowed and the turbine still moved while the motor was in operation (Image 1 & 2).

Image 1: Bowing under Old Platform Image 2: Turbine Strapped on Old Mount Courtesy of SDMay10-17

Since we could not risk damaging our equipment with this previous setup, a new platform has been designed. With the guidance of Leland Harker we compared two alternatives during the planning phase of the project. Ultimately, we decided that we would use a thicker wood base and aluminum support rods to construct the platform for both the turbine and the motor.

Materials: 80/20 Inc. Rectangular Extruded Aluminum RodsSteel L Brackets¾”-1” slab of Medium Density Fiberwood1 ½” Schedule 40 Steel ConduitRound Rubber GasketM5x40 SS Socket Head ScrewsAluminum Plating

Construction:

A 36” x 28” sheet of MDF (Medium Density Fiberboard) lays flat on the surface of a table. The base of the turbine is bolted to the MDF as done in the previous platform. A 4” long steel conduit threaded at both ends screws into the bottom and top of the turbine mount. Two extruded aluminum rods extend from the MDF base to the face of the wind turbine. These rods are supported at the base by four L brackets screwed into the MDF. The two rods and an aluminum plate connect to the face of the turbine by the socket head screws, which lock the turbine in position, not allowing it to sway back and forth (Image 3 & 4). An extruded aluminum

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mounting box for the motor is braced and connected to the MDF platform with L brackets. The mounting box matches up to the two rods bracing the turbine keeping the motor at the exact coupling height needed to match the turbine (Image 4). Rubber gasket material is used to minimize any vibrations found in the mounting system. The entire turbine and aluminum rods are grounded as per NEC 250.52, item 5 and NEC 250.53, item A.

Image 3: Conceptual Drawing of New Mount

Image 4: Partial CAD model of new mounting system designed by Leland Harker

3.2.Sensors

DAQ sensor interface

The NI-USB 6008 is the digital/analog data acquisition tool we will be using. It allows for both analog and digital signals to be recorded. This DAQ was acquired by the previous groups and is the best option for this type of system. Below you will find the pin diagram and terminal modes for this device.

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Image 5: Pin Diagram Courtesy of National Instruments

Image 6: Terminal Modes Courtesy of National Instruments

RPM

Reed Sensor Hall Sensor Optical Sensor

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Image 7: Reed Sensor operation Image 8: Hall Sensor operation Image 9: Optical RPM SensorCourtesy of: Left (http://www.chicagosensor.com/images/HowItWorksReed.jpg), Center (http://upload.wikimedia.org/wikipedia/commons/7/7e/Hall_sensor_tach.gif)

We are creating a new mounting system so the bulky fragile RPM sensor the previous group built on a testboard was not ideal for continuous use. The RPM sensor they created was an optical detector and a Schmitt trigger to create a digital signal for every turn the motor made. We wanted to replace this easily with something more compact and easily mounted. Our three options are shown above and consist of a reed sensor, a hall sensor, or new optical sensor. The reed sensor was determined to be too fragile, the optical sensors all required a mounting system to be fabricated, and the hall sensor is a linear device. We did find some hall sensors have additional circuitry to create a digital device like the one we are replacing, and they have a lot of different packages and mounting options.

Image 10: Hamlin Hall Sensor Image 11: Hamlin Hall Sensor Wire Diagram

Courtesy of: http://media.digikey.com/photos/Hamlin%20Photos/55100-3H-02-A.jpg

The RPM sensor we chose is the Hamlin 55100-3H-02-A-ND. The 55100 is a mini flange mount hall effect sensor. The 55100 was chosen for the prefabricated mounting design over other similar sensors. The model we have chosen has a operating voltage of 3.8 to 24v, this will allow the 5v output of the DAQ to power the sensor rather than an external supply as previously used. The 55100 has a built in switch and comparator to act as a digital sensor rather than the typical linear hall sensor. This will make placement into the already designed interface easy. We have chosen the sensor with an activation distance of 18.0mm which gives us enough distance to not be activated in error, and does not have to be mounted in a manner that is difficult.

DAQ Pin 31 will provide power to our hall sensor.DAQ Pin 32 will provide the ground to our hall sensor.DAQ Pin 29 will connect to the signal wire of our hall sensor.We will use the LabVIEW software and our sensor to provide our RPM data.

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DC sensors

The DC sensors we use are current transducers. They will allow us to see the current being generated by the wind turbine, and the current powering the inverter from the batteries. DAQ Pin 11 is the red wire of CT1.DAQ Pin 10 is the black wire of CT1.DAQ Pin 5 is the read wire of CT2.

We will also need to get values of the voltage, we will use a voltage divider to lower the voltage into the DAQ and use our LabVIEW interface to calculate the accurate value.

Wind Sensor

Image 12: Anomemter and Wind Vane Image 13: LabVIEW wind speed input block diagram

Courtesy of: Left (http://www.nrgsystems.com/~/media/ProductImages/1900/1900.ashx), Center (http://www.nrgsystems.com/~/media/ProductImages/1904/1904.ashx), Right (http://forums.ni.com/ni/attachments/ni/170/236901/1/read%20lines.JPG)

The wind sensor data is provided by the “Ridgeline Meteorological Sensor Network” senior design group. They will be providing us with a USB receiver to receive their data. They will also be providing us with a program that will generate a text file with the data received from the wind sensors. We will be using our LabVIEW interface to simulate the data received from this file.

3.3.Wind Turbine

We are using a Southwest Windpower Air X 400 wind turbine for our project. This was chosen by a previous team and the budget will not allow us to choose a one with more controllability.

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This turbine is designed to charge a battery bank, where this battery bank is used for small power consumption. We wish to use the turbine as a primary source of power and the battery bank secondary. Even though its application is not direct, we are able to use this turbine to generate power corresponding to the simulated wind data.

Unfortunately, the turbine will not operate if the battery bank does not have a minimum of 7V DC. Therefore, the load will need to be disconnected before the batteries reach this level. Another drawback is that the turbine is designed to slow down and then shut off if the battery bank reaches its maximum capacity. This is done in order to avoid overcharging and damaging the battery bank. We want to use all available power on the load when the batteries are not charging, so we are able to bypass this regulation mode by setting the voltage at which it enters regulation mode to 27V DC. The previous team did this by connecting a 27V DC power supply to the turbine’s leads and adjusting the potentiometer on the turbine. This is higher than our 24V DC battery bank, so the regulation mode is not effective.

3.4.Inverter

The inverter is one of the most crucial parts of any renewable energy system. It takes 24V DC power from the battery bank supplied by the turbine and converts it to 120V AC for use by the load. The senior design teams prior to ours chose the single phase Outback GTFX2500 VA grid-tie inverter for this process. The inverter also contains an internal controller that manages the input voltage needed for a stable output voltage. This inverter was picked to match the input voltage and maximum power of the turbine (400W & 24V DC) and the output current, voltage, and power of the load (Single Phase 120V AC & 10A load). This particular inverter is a hybrid type which can be used in either stand-alone or grid connected mode. For our project, we operate the inverter in stand-alone mode because we are not connecting directly to the Iowa State grid.

Image 14: Inverter System

3.5.Controller For Turbine Powered Load

LabVIEW Controlled:

For this option we will be expanding on the LabVIEW control interface created by the previous

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senior design group. First we will be importing the output of the wind sensors on the roof in the form of a text document into LabVIEW via a module created by a NI employee. This module takes in the text document and parses it into a vector format. The values of this vector will correspond with wind speeds which will then be translated into a voltage which corresponds to the desired RPMs. This converted output will then be fed into our power source via the GPIB. Through this, we will have updates at a minimum of once every minute.

Direct Control:

This option was recently presented to us by Dr. Ajjarapu as a means of motor control so all of its ins and outs have not yet been explored. However the idea behind this is a system is simply a voltage regulator. For this option we will set the power source to a specified voltage and phase and hook this system up between the power source and the turbine. Using a simple serial interface on the voltage control system we can input our desired voltage levels and the system will only let that level of voltage pass from the source to our turbine. This solution will allow us to overcome the current problem we are having with LabVIEW taking in the information given to us by the wind speed sensors.

Image 15: User Interface Display Image 16: User Interface block diagram

The figure above displays the User interface for manual control of Power supply, this is done through the Voltage dial or inputing a value, the figure on the right displays the LabVIEW motor logic.

3.6.Interface

The previous team designed a full user interface for use with this project. The user interface was designed with LabVIEW. The interface displays measurements and controls the output of an adjustable power supply. The NI USB-6008 DAQ is used to bring in readings from various sensors. The DAQ takes readings from the sensors and inputs them into LabVIEW’s block diagram editor. Some of these readings require mathematical manipulation to be correct. The voltage readings are multiplied by 4.9, and the current readings by 10. To find the power we simply multiplied the calculated voltages and currents. The gauges on the front panel are used

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to display these values.

Interface Front Panel

We want to improve the interface motor controls. The motor is controlled by the three phase power supply. LabVIEW communicates with the power supply through a GPIB-USB cable. The motor speed is adjusted using a voltage knob on the interface. The voltage knob changes the output voltage of the power supply to the motor therefore changing the speed of the turbine. This does not allow the speed of the turbine to change according to the changing wind speeds. As mentioned before, we will be changing the primary input to the motor. Instead of using the voltage knob we will be taking the real time data received from the wind sensors and using that as our new input to the motor. The wind sensors will send an output file with all the data. LabVIEW will take the data from the output file and create an array of values. This array will ultimately replace the voltage knob as the primary source for adjusting the output voltage to the motor. We will be able to collect enough data to generate a full 24 hour wind profile. The turbine will adjust speeds according to the wind profile allowing us to simulate the operation of the turbine for a whole day if desired.

4. System and Unit Level Testing Cases

The following section defines the various test cases that will be conducted. Unit level testing will be conducted to confirm the operational specifications and capabilities of the individual components. A full system test will be conducted to confirm that overall simulation will meet the specific requirements stated earlier.

4.1.Motor Control

The unit test case for the motor control will be performed after we have a stable platform. We have already tested and verified that the motor is able to change speed as we vary both directly from the power supply and through the LabVIEW interface. Our next step will be to test the motor rotation with the RPM sensor and the output power with the turbine.

4.2.Turbine Testing

The turbine will be tested using the manufacturer supplied manual. The following tests can be found in the Air X Owners Manual. From the three tests given we have verified the turbine is in proper working order.

Test 1 (On/Off Testing)This test will determine the working order of the internal on/off switch. When the turbine leads are shorted it will prevent the turbine from spinning freely.1. Remove blade assembly from turbine and place in a safe location. (Do not stand the blade

assembly against a wall.)

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2. Spin rotor shaft with your fingers or the Allen Wrench provided while at the same time connecting and disconnecting the Red and Black yaw wires. (Be careful not to press the rotor shaft into the turbine body.)

3. With the yaw wires connected, the rotor shaft should become more difficult to rotate and feel “lumpy”. With the yaw wires disconnected it should spin freely. If these conditions do not exist, you should contact your turbine dealer or Southwest Windpower.

Test 2 (Battery Connection Testing)This test will determine if the wind turbine’s circuitry senses a battery connected. When a battery is connected the LED indicator will blink to show the controller is functioning. 1. Remove blade assembly from turbine and place in a safe location. (Do not stand the blade

assembly against a wall. Do not press the rotor shaft into the turbine body.)2. Connect the turbine power wires to the appropriate battery terminals: RED=Positive, BLACK

= Negative.3. Each time the AIR-X is connected to a battery, the LED will blink two times to indicate that

the controller is running properly. You may need to wait 10 seconds between iterations of this test in order to let any internal voltage drain. If the LED does not blink when the AIR-X is connected to a battery, you should contact your turbine dealer or Southwest Windpower.

Test 3 (Rotation Response Testing)This test will determine if the turbine’s circuitry will allow it to generate power at the manufacturer specified rotation. Above 500 RPM the turbine should generate power and charge the battery bank.1. Leave the AIR-X connected to your battery bank. With a 5/16” hex drive in an electric drill,

spin the rotor shaft while observing the LED. Be very careful not to push in on the rotor shaft while performing this test. Doing so could damage the control electronics.

2. Below 500 RPM, the rotor should spin freely and the LED should remain off.3. At 500 RPM and above, the AIR-X should be charging the battery. You should begin to feel

some resistance on the rotor shaft and the LED should turn on. The shaft should have a slight resistance to rotation, but should still rotate fairly easily. If the shaft is cogging (difficult to rotate), contact your turbine dealer or Southwest Windpower. Be sure your battery voltage is not high enough to activate the regulation mode during this test.

4.3.Battery Testing

The batteries should hold a charge of 12V each, giving 24V in series. The test will include a voltmeter on each battery to verify correct operating voltage. If the voltage is low the batteries will need to be charged to full and retested to verify correct voltage. If voltage cannot be achieved the battery will need replaced.

4.4.Inverter Testing

The inverter is used to convert the DC power from the battery to AC power. To test the inverter we will need the batteries charged. The battery bank consisting of two 12V batteries will supply

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24V total to the inverter. The batteries supply the inverter terminals positive and negative voltages. The inverter is also connected to a ground, and a jumper is used to turn the inverter on. When the inverter is connected to the battery bank and the jumper is in place, it will display what operation mode it is in. If a solid green LED is shown, no further testing will be needed for our purposes. If a solid red LED is shown our inverter may need serviced. Any servicing must be done by the manufacturer.

Image 17: Inverter Modes Courtesy of Outback

4.5.Load Testing

Load testing is another unit level test we will conduct. The load provided to the system consists of four 75W incandescent light bulbs connected in parallel. Two light bulbs, 150W, is the base load and the other two light bulbs, 75W each, are used to increment the load through light switches.

To test the base load is working properly we will connect the inverter to a fully charged battery bank. The base load should stay illuminated. To test the two additional increments of 75W we will turn each individual light switch on and confirm the appropriate light bulbs are lit. This test can also be performed by the end user as another interface to study the power produced by the system.

4.6.Sensor Testing

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The current transducers are used to detect the current flowing through a wire. We are using them to calculate our power output of the turbine, and our power output of the batteries. To test them we will pass a wire through the CT and run a current through that wire. Using a multi-meter we can measure the output voltage, and respective changes with various currents. If we find the CT’s to be non-functioning they will need to be replaced.

We have chosen to use a low cost Hamlin Hall Effects Sensor to record the AC motor’s RPM. We will test the hardware using a multi-meter and the AC motor which allows us to test different frequencies of the motor match to the RPM sensor results. The sensor will react to a magnet moving near the “centre of sensitivity” on the hall sensor. If the sensor does not react to a magnet it will need to be replaced.

The voltage divider in our system converts the full output of the turbine to a smaller voltage that is safer for the DAQ. To test our voltage divider we will apply a voltage and verify it is correctly dividing the voltage based on the resistance values. If the output does not correspond the calculated values the resistors will need replaced.

4.7.Full System Test

A final test will be performed from start to finish that fulfills all the requirements of the designed system. A checklist will be followed and repeated to ensure that no errors occur. If a mistake or miscalculation arises while testing, we will stop take note of it, resolve the issue and continue the process over.

Steps:

1. Check all wires, bolts, screws and the coupling for secure connections.2. Remove all unnecessary materials from the testing area.3. Insure that all safety precautions are followed. For example, high voltage signs are

posted and more than one person is in the room during testing.4. Turn on LabVIEW GUI and load all necessary drivers.5. Turn on all power sources, check LED status to ensure that all sources are active.6. Make connection with wind sensor data and upload the wind profile for the current conditions.7. Run program that utilities data profile and automatically controls input voltage and frequency to the motor.8. Check LabVIEW GUI for RPM, current, voltage, and power readings.9. Check that wind turbine LED has lit up.10. Monitor battery voltage to ensure they are not overcharged.11. Make sure the automatic stop switch will kill the motor.12. Turn motor back on and start data profile again.13. Check that the inverter has turned on and LEDs signify the quality of the battery power.

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14. Ensure that the two light bulbs are lit and flick the switch to add more lights (load).15. Check LabVIEW GUI for RPM, current, voltage, and power readings.16. Run for at least 5 to 15 minutes to ensure that the motor changes in sync with the

weather data that is loaded into the program.17. Turn off motor first through the GUI. Then shut off all power supplies. Turn the wind turbine switch to lock it in the off position. Remove the power jumper from the inverter. Now the system has been completely shut down.18. Run this process several times with varying weather data and time inputs.

5. Recommend Project Continuance We recommend that this project continue so that the power generated by the wind turbine can be incorporated into the Iowa State University power grid. Our interface can also be reused to repeat this simulation for other buildings on campus. When budgets allow, this turbine and others could be placed outdoors and our interface can be modified to monitor the power generated.

6. Estimated Resources and Schedule

The following section includes the resources we will use and our current project schedule.

6.1.Tasks

Task 1 - Familiarize with ProjectTask 2 - Initial System TestingTask 3 - Draft Project PlanTask 4 - Project PlanTask 5 - Website BuildingTask 6 - Familiarize with GUITask 7 - Procure EquipmentTask 8 - Constructing New Test Bench Task 9 - Final Design DocumentTask 10 - Load ImprovementTask 11 - Wind Sensor ImplementationTask 12 - Technical Manual

6.2.Estimated Resources

Estimated Individual Team Member Effort (hours)

Task: 1 2 3 4 5 6 7 8 9 10 11 12 Team Member: TotalsAndrew Nigro 7 7 3 8 20 20 10 20 10 40 20 20 185

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Chad Hand 6 2 3 8 15 60 10 20 10 20 20 10 184Luke Rupiper 7 5 3 8 20 50 20 10 20 20 20 183Ryan Semler 6 5 3 8 30 20 10 40 10 20 20 10 182Shonda Butler 16 3 6 8 20 10 20 10 20 60 10 183Totals 42 22 18 40 65 140 90 120 50 120 140 70 917

Sheet 1: Estimated Individual Team Member Effort

Required Resources

Parts and Materials:Team Hours

Other Hours

Cost without Labor

Cost with Labor ($20/hr)

Purchased by Phase I: Turbine- Air X 400 $700 $700Inverter-Outback GTFX2524 $1,400 $1,400Battery Bank $100 $100NI USB-6008 $170 $170

Purchased by Phase II: Coupling $112 $112Current Transducer $21 $21Stop Switch $16 $16Kikusui Power Supply Borrowed $03-phase AC Motor Borrowed $0

Phase III Estimates: Mounting Platform: 44 $50 $850Load Platform 20 $20 $420Wire 5 $10 $110RPM Sensor 40 $10 $810Printing Costs $15

Services: Wind Sensor- Other Senior Design Group (Dec 10-05) 2 $40Technical Manual- Engl 314 Group 20 $400Knowledge of Project- Dr. Ajjarapu 30 $600Knowledge of Project-Previous Senior Design Team member 2 $40Turbine Expertise- National Instruments Forums 1 $0Totals: 109 55 $2624 $5789

Sheet 2: Required Resources

6.3.Schedule

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PROJ

ECT T

IMEL

INE

Brea

kW

eek

WK1

WK2

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0W

K11

WK1

2W

K13

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4W

K15

WK1

6W

K17

8/23

-8/2

88/

30-9

/49/

6-9/

119/

13-9

/18

9/20

-9/2

59/

27-1

0/2

10/4

-10/

910

/11-

10/1

610

/18-

10/2

310

/25-

10/3

011

/1-1

1/6

11/8

-11/

1311

/15-

11/2

011

/22-

11/2

711

/29-

12/4

12/6

-12/

1112

/13-

12/1

8An

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TASK

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12

Project Schedule

TEAM NAME: SDMAY1101PROJECT MEMBERS: Andrew Nigro , Shonda Butler, Ryan Semler, Chad Hand, Luke RupiperPROJECT TITLE: Wind Turbine Design and Simulation

ANTICIPATED TASK DEADLINES, WORK LOAD, TASK LEADER, AND TASK DESCRIPTIONS

TASK START TASK DEADLINE TASK # WORK LOAD TASK LEADER TASK DESCRIPTION9/9/2010 9/23/2010 1 Shonda/Andrew Familiarize with project

9/15/2010 10/14/2010 2 Ryan Initial system testing9/21/2010 9/28/2010 3 Luke/Shonda Draft Project Plan9/21/2010 10/14/2010 4 ALL Project Plan9/28/2010 10/8/2010 5 Ryan Website Building9/15/2010 12/13/2010 6 Chad Familiarize with GUI10/7/2010 12/13/2010 7 Andrew Procure Equipment

10/14/2010 11/14/2010 8 Ryan Constructing new test bench10/14/2010 12/3/2010 9 ALL Final Design Document

1/10/2011 3/11/2010 10 Andrew Load improvement1/10/2011 3/11/2010 11 Shonda Wind sensor implementation

9/9/2010 3/11/2010 12 Chad Technical ManualSheet 3: Task Dedications

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Sheet 4: Task Progression

7. Closure Material

The following includes the closure material consisting of our project team information and a closing summary.

7.1.Project Team Information

Client:Iowa State University : Department of Electrical and Computer Engineering

Faculty Advisor:Dr. Venkataramana Ajjarapu

1122 Coover Hall Ames, IA 50011-3060 Phone #: (515) 294-7687 vajjarp@iastate.edu

http://www.ece.iastate.edu/who-we-are/faculty-and-staff/faculty-new/index/detail/abc/289.html

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Student Team:Sheet 5: Student Contact Information

Andrew NigroElectrical Engineering2129 Sunset DrAmes, IA 50014-7074Cell: (402) 917-4753Email: anigro@iastate.edu

Chad HandElectrical Engineering3114 Woodland StreetAmes, IA 50014-7074Cell: (563) 210-6631Email: chand@iastate.edu

Luke RupiperElectrical Engineering3506 Lincoln Way Unit 22Ames, IA 50014Cell: (612) 840-4465Email: lrupiper@iastate.edu

Ryan SemlerElectrical Engineering1005 Pinon Dr Unit 3Ames, IA 50014-7944Cell: (515) 451-9336Email: rsemler@iastate.edu

Shonda ButlerElectrical Engineering1317 Roosevelt AveAmes, IA 50010Cell: (210) 834-6114Email: sbutler@iastate.edu

7.2.Closing Summary

The United States continues to increase its electrical consumption and recently has stressed the need for solutions from renewable resources. Our project focuses on the electrical needs of Iowa State University and aims at taking advantage of an abundance of wind energy in the Iowa area. By creating a simulated environment, we can work in a controlled laboratory to test load control with a wind turbine. Our goal is to improve the previous system by using real-time wind data to control our turbine. If we can accurately monitor the output of turbine and control its ability to feed a load, future groups will be able to easily use our system and interface to design other wind turbine systems for campus buildings.

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8. References & Technical SpecificationsThe final section of this document includes the technical specifications of each component.

8.1.Technical Specifications

Technical Specifications Inverter:

Nominal DC Input 24 VDCContinuous Power Rating 2500 VAAC Voltage/Frequency 120 VAC 60 HzContinuous AC RMS Output 20.8 Amps ACIdle Power 6-20 WattsTypical Efficiency 92%Total Harmonic Distortion 2-5%Output Voltage Regulation ± 2%Maximum Output Voltage 50 amps AC RMSAC Overload Capability Surge 6000 VA

5 seconds 4800 VA 30 minutes 3200 VA

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AC Input Current Max 60 amps ACAC Input Voltage/Frequency 80-150 VAC 58-62 HzDC Input Range 21-34 VDCWeight 56 lbs

Technical Specifications DAQ NI 6008 USB:

8 analog inputs (12-bit, 10 kS/s) 2 analog outputs (12-bit, 150 S/s); 12 digital I/O; 32-bit counter Bus-powered for high mobility; built-in signal connectivity OEM version available Compatible with LabVIEW, LabWindows/CVI, and Measurement Studio for Visual

Studio .NET NI-DAQmx driver software and NI LabVIEW SignalExpress LE interactive data-logging

software

Technical Specifications LEM LA 55-P Current Transducer:

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Technical Specifications Southwest Windpower Air X 400:

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Rotor Diameter 46 in.Weight 13 lbStart-Up Wind Speed 8 mphVoltage 24 VDCRated Power 400 watts at 28 mphTurbine controller Micro-processor based smart internal regulatorBody Cast aluminumBlades 3-Carbon fiber compositeOverspeed Protection Electronic torque controlKilowatt Hours/Month 38 kWh/mo at 12 mphSurvival Wind Speed 110 mph

Technical Specifications Hamlin Hall Sensor:

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System Block Diagram created in LabVIEW

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8.2 References

Our references have been credited throughout this document.

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