1. Functional Requirements 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 Non-Functional Requirements 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 Deliverables Wind turbine and tower Control electronics and power electronics Manual 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) 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) 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 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 Project CostsProject Hours 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. 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. 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. System Block Diagram