1. W IND T URBINE D ESIGN AND I MPLEMENTATION P HASE III P ROJECT O VERVIEW Our senior design team expanded 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. The system monitors voltage, current, power, and wind speed. Outside conditions are simulated through data received from wind sensors provided by a past senior design group. Power generated from the turbine charges a battery bank. The direct current (DC) power is converted to alternating current (AC) through an inverter. An AC load consisting of light bulbs and an outlet is powered by the system. The end product resembles a small scale renewable electrical network. D ESIGN R EQUIREMENTS F UNCTIONAL : The turbine will generate a 24V DC output with a 400W Peak The test-bed connection will serve to simulate a load The motor will simulate outdoor wind speed gathered by anemometer The RPM sensor will accurately reflect the speed of the motor within ±5% The user interface will display accurate measurements of DC voltage, current, and RPM N ON -F UNCTIONAL : The turbine will be remounted to a new stable operating platform The project will be documented through a technical manual and in-depth schematics Wiring and connections will be redone in a professional manner S UMMARY The United States continues to increase its electrical consumption and recently has stressed the need for solutions from renewable resources. This 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, users can work in a controlled laboratory to test load control with a wind turbine. Our goal is to improve the system by using real-time wind data to control the turbine. If we can accurately monitor the output of the 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. S CHEDULE, C OSTS, & H OURS Costs RPM Sensor$ 7 2 x 12V - 90 aH Battery $ 452 Turbine Mount $ 122 Inverter Breaker $ 95 Turbine Breaker $ 6 Total $ 682 T ESTING CT S ENSORS Used LabVIEW DAQ Assist and power supplies to the test current sensors RPM S ENSOR Used LabVIEW DAQ Assist to test the RPM sensor Hardware tested by swiping a magnet across the sensor area AC M OTOR Interface and power supply were connected with GPIB-USB cable Power supply settings tested using LabVIEW Motor connected to power supply, voltage and frequency set using the interface T URBINE Verified coupling between turbine and motor are secure Verified battery connection to turbine B ATTERIES Verified batteries would fully charge Verified batteries would properly power inverter I NVERTER Verified inverter could power a small AC Load of 1 x 75W light bulb L OAD Verified load can be powered by inverter F ULL S YSTEM Ensure display is accurate and system is operating safely I NTERFACE Data from the wind sensor network is imported into LabVIEW through a receiving node and USB. This data is used to control the motor speed which is coupled to the turbine. Data from voltage and current sensors is imported into this interface through a NI-6008-USB and DAQ Assist software. These measurements monitor different parts of the system and are displayed on the GUI. This user interface is automated to start the motor by simply clicking an “ON” button after turning on the power supply and running the program. W IND S ENSOR I NTEGRATION Data from wind sensors is collected from a transceiver that was provided by Senior Design Team SD Dec10-05. Three nodes placed on top of campus buildings form a self-healing mesh network. The real time data from these nodes are averaged every ten seconds to provide an accurate wind profile without excessive spikes which could exceed motor ramp rates and damage the turbine. This data is then imported into LabVIEW and used as a motor control to simulate the wind speed on the turbine. M OUNT The mount for the turbine and motor was fabricated out of extruded aluminum pieces and an aluminum plate. The turbine face is mounted directly to the aluminum plate and the motor sits on the base which allows for a level connection. This mount solved the issues of turbine movement, vibration, and direct coupling that were observed in the old system. S YSTEM D IAGRAM RPM S ENSOR Hall Sensor output pulses ~5 to ~0V when a magnet is near Reads from the coupling between the motor and the turbine Computation of RPM is done in LabVIEW L OAD A load is used to demonstrate the operation of the system by simulating actual loads used in a common household. The load also provides a visual reference of the power being produced. A 30 Amp AC breaker is connected between the inverter and the load to prevent any possible damage to the inverter. The load consists of two 75W incandescent light bulbs and an outlet connected in parallel. One of the bulbs is controlled by a light switch. The light bulbs act as a resistive load so the light intensity will be affected by the variation in power produced. This is why we also chose to use an outlet-load so the little variation in power will not be noticed. T EAM : SDMAY11-01 W EBSITE : http://seniord.ece.iastate.edu/may1101/ A DVISOR : Dr. Ajjarapu T EAM M EMBERS : Shonda Butler (EE) Chad Hand (EE) Andrew Nigro (EE) Luke Rupiper (EE) Ryan Semler (EE)