Transcript Cheryl Limasx - The University of Texas at Arlington

Smart-Grid: Power Distribution and Monitoring Application
Cheryl Limas, Daniel Rendon, Advisor – Dr. David Wetz, Advisor – Gregory Turner
Department of Electrical Engineering, The University of Texas at Arlington, Arlington, Texas 76019
Research Experiences for Undergraduates in Sensors and Applications
Abstract
In this project, an application was designed to monitor the power distribution
between different energy sources. There are various sources of energy used to
power homes or businesses, but very few places are able to monitor the intake of
power and control which energy sources they would like to use. This application
created is one that can make a simple micro-grid into a “Smart-Grid”. It allows
users the ability to determine whether or not enough power has been produced,
and if so, which sources would be best to use. It is important to be able to control
and make critical decisions based on the different sources being used and how
much power they are generating at a given time. That is why this application was
created, to let the user know the distribution of power among the energy sources
being used and to give them the choice of distribution. Along with these choices,
the application is able to monitor the batteries being used in the grid and warn the
user if they are running low and how much time they have left before they
discharge.
Energy Sources
The micro-grid we worked with involved solar panels, vertical wind turbines, and
two marine batteries, each rated at 12-volts. The setup of the solar panels and
wind turbines is shown in the Figure 1 below.
Solar Panels
Results
Materials
Control and Monitoring Equipment
The programming software used
when designing the application was
LabVIEW 2012. We used a
CompactRIO similar to the one
shown above to control and monitor
our system.
When monitoring the voltage produced by each source, charts were plotted while
the VI ran to show the user the production of energy coming from each source.
Before being able to use the data gathered, calibration among the sensors needed
to be implemented.
Vertical Axis Wind Turbines
Introduction
The purpose of this application is to make a simple micro-grid smarter. As a user,
you would be able to make the critical decisions needed when power is running low
or when you decide to use a different energy source. Being able to control how
your energy is used is one of the many features that can be incorporated into an
application like this one.
Today there are hundreds of mile long transmission lines, that deal with loss
and potential blackout to major cities. If residential subdivisions found a way to
incorporate solar panels and wind turbines, there would be fewer loss of energy
through transmission and better control over the power produced using
applications like the one created for in this project.
Throughout the day this application can record and measure the amount of
energy produced when a residential family has left to work or school. It would store
the energy created in battery like equipment and then use the energy once the
family returns home. The application would let the user know how much time
before the energy stored throughout the day runs out. Once it is time for residents
to switch to the main source, or the utility company, they would do so, but all the
while saving money with the energy they made during the day.
Code Implementation
When designing the application, we used the FPGA sampling method to sample
data once every 100us. Figure 1, the main VI, was then changed to record data
about every minute. Data from the sensors was put into a FIFO write function. This
data is read and interpreted by the program shown in Figure 1. The code shows
the functions used to monitor the voltage produced from each source.
Figure 3 – The data being generated
while both the wind and solar panels
were turned off. Here the batteries
are powering the DC bus.
Figure 1 – UTA Renewable Energy Sources
Methods
DC Bus
Inverter
AC Bus
"DieHard Platinum Marine Battery Group Size 31M." Sears.com.
Sears Brand, 2013. Web.
"NI LabVIEW for CompactRIO Developer's Guide." NI CompactRIO
Developers Guide. N.p., n.d. Web.
Load
Energy
Storage
References
"Hi-VAWT DS-300 Vertical Axis Wind Turbines." Hi-VAWT DS-300
Vertical Axis Wind Turbines. Hi-VAWT Technology Corp., 2012.
Web.
2 & 3MicroGrid
Charge
Controller
Our grid consisted of solar panels, wind turbines and batteries. The application was
designed to let the user know which energy sources were producing output power
and the precise measurement of current and voltage drawn or output from each
source. An inverter is monitored in the application to give the user the option of
converting the DC power obtained from the energy sources to AC power in order to
power a facility or residential home.
The application monitors the status of the batteries being used as well.
Based on the consumption of energy, the monitoring system lets the user know
whether or not the batteries are charging or discharging. If the batteries are
discharging, an icon is used as a visual representation of the status of the battery.
The amount of time left before the batteries discharges completely is also shown.
"Hall Effect Current Sensors L03S***D15 Series." Tamura, Mar. 2009.
Web.
Grid Setup
When designing the application, the setup of all the equipment was necessary
before beginning. The layout of the micro-grid is shown below.
Renewable
Energy
Summary
Figure 4 – Application results while
monitoring energy sources.
"Schott Solar Poly 230 Solar Panel US." Schott Solar Poly 230 Solar
Panel US. Civic Solar Inc., n.d. Web.
"Sealed GFX1312E (50Hz)." Outback Power Inc. N.p., 2013. Web.
The renewable energy sources were able to charge the batteries in series when
running low. Charge controllers kept the energy sources from over-charging and
prevent over-voltage. The AC bus allows other micro-grids to connect in order to
help provide energy when needed.
Code Implementation
Acknowledgements
We thank Dr. David Wetz for giving us the opportunity to work in the
Micro-Grid laboratory. We also thank Greg Turner for being a great
mentor. Funding for this project was provided by NSF grant # EEC1156801.
Hall Effect Sensors were used to measure the voltage and calculate the current
drawn or produced by each source. Its characteristics are shown below.
For Further Information
Please contact [email protected]. More information on this and related
projects can be obtained at wiki.uta.edu/display/PPELab/Home.
An inverter was used as well to convert our 24-Volts produced off of the DC bus to
AC.
Figure 2 – Code implemented to monitor the distributed energy
among the different components.
Figure 5 – Battery status section. Plots the discharge of battery
while in use. Warns user of time left before battery completely
discharges depending on power consumption.