Transcript Poster - ECpE Senior Design

Problem Statement
Iowa State University announced on January 2008 that it aims to become a model of energy
efficiency. To help this vision become a reality, we wanted to create a wind turbine that would
serve as an attraction for future engineers and as a tool for alternative energy experimentation or
research.
Proposed Solution
The proposed solution was to install a small-scale wind turbine on the roof of Coover Hall. The
turbine would generate between 500 and 1000 Watts of AC electricity and feed it to the Coover
electrical grid. We decided that the best choice for turbine was a fixed speed, upwind type that
faced west.
Functional Requirements
Non-Functional Requirements
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• Enough space below the blades for a person
to stand under them safely
• Comply with building code weight and height
limits
• Components comply with federal and state
electrical regulations
• Turbine type is fixed speed and upwind
Generate an AC current
Supply an output of 500 to 1000 Watts
Supply power to the Coover Hall grid
Turn off in high wind speeds
Protect internal components from power
surge
• Controls connect to a display to display data
Deliverables
• Wind turbine and tower
• Control electronics and power electronics
• Manual
Design
Mechanical Safety
• Brake can be applied for maintenance
• Furling tail turns the nacelle and blades out of the wind whenever it is too strong
• Tower is high enough (15’ height) that a person can safely walk under the blades
• Tower base is wide to keep tower and nacelle stable (10’x10’ square base)
To provide a more accurate analysis of our equipment we have tested all equipment
individually, as subgroups, and as a whole system.
Individual
Motor
• The AC motor was driven by a DC motor to measure voltage and current output
• Capacitors were used to build up residual magnetism in the AC induction motor. We will
connect three light bulbs as loads and measure the voltage and current output.
• The AC motor was connected to the grid and driven at 1800 RPM to measure its power
output. At 1800 RPM, the AC motor was floating, which means that it was not drawing nor
providing power to the grid. Unfortunately, the DC motor could not drive the turbine past
1800 RPM, but we will use another source to drive the AC motor.
Gearbox
• The output shaft was marked, and the input shaft was rotated to verify that the gearbox
has a 1:10 input to output ratio
Brake
• The brake was tested to make sure it keeps the blades, gearbox, and motor from rotating
Subgroups
Nacelle
• After installing all components in the nacelle, the mechanical resistance of the system
was tested by turning the shaft to make sure everything was lined up correctly.
Control System
• RPM sensor was tested using a computer fan that had its speed sensor wire connected to
a computer for actual RPM reading
• Output that activates contactor was tested to ensure that it is only on when the motor
RPM is between 1800 and 1860 RPM
Whole System
Nacelle/Control System/Protection System:
• Before a permanent installation into the grid our system must be tested for safety.
Electrical Safety
• Motor has thermal overload protection that disconnects it from grid
• Protection circuit disconnects turbine from grid whenever voltage, current, or wind speed
are not within specifications
• Lightning rod mounted on nacelle diverts energy from lightning strike
Implementation
Mechanical
• Nacelle is made of ¼” steel plate for sturdiness and durability
• Blades are made of fiberglass composite and are 9.2’ in diameter
• Gearbox increases speed from the blades by a factor of 10 to drive motor
Project Costs
Project Hours
Electrical
• Generator is 208 VAC, 3-phase, 1.5 HP induction motor
• Microcontroller monitors motor speed and connects it to grid when above synchronous
speed (1800 RPM)
• Motor can produce an estimated 330 Watts to the grid
System Block Diagram
Wind energy is a good sources of renewable and environmentally friendly energy. Our project is
our attempt to show and provide an example of this wonderful resource. The turbine in this
project is designed to be tied into a power grid system and provide a very low amount of
supplementary power to the grid. With this system in place Iowa State and the Electrical
Engineering department can be viewed as leaders in the pursuit of “green” energy.
Special thank you to Tom Donney, Lee Harker, Dr. Greg Smith, and Trishna Das for providing
materials, advice, and/or help in our project.
Client
Dr. Dionysios Aliprantis
Faculty Advisor
Dr. Venkataramana Ajjarapu
Team Members
Dario Vazquez (CprE)
Nick Ries (EE)
Luke Donney (EE)
Lindsay Short (EE)
Chris Loots (EE)
Dustin Dalluge (ME)