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RFID senior project
Final Report
University of Maine Mechanical Engineering Department
Adam Freund, Amanda Mayette, and Matthew Sevey
5/2/2012

ABSTRACT

The Radio Frequency Identification senior design project was created to provide power to a tag detection system using an alternative form of energy. The system requiring power was part of a US Geological Survey study on the migration of fish through the Dover-Foxcroft, Maine area. Wind, water, and sun light were all initial options for the source of power. An array of four solar panels was the final solution, as it proved to be the most dependable and least problematic solution. Both wind and water are dependent on the fluid flow conditions and need to be tested in controlled environments. Due to the low average wind velocities in the target area, and due to the limited amount of testing that was safely available for hydropower, these options were eventually eliminated from consideration.

TABLE OF CONTENTS

ABSTRACT ii

TABLE OF CONTENTS iii

TABLE OF FIGURES v

CONTRIBUTIONS vi

Adam Freund vi

Amanda Mayette vi

Matthew Sevey vi

1.0 INTRODUCTION 1

2.0 DESIGN DESCRIPTION 1

3.0 CONCEPT DESIGN PROCESS 3

3.1 System Energy Usage Requirements 3

3.2 Power Generation Options 5

3.3 Selection of Components 7

3.3.1 Hydro-turbine 7

3.3.2 Solar Panels 8

3.3.3 Regulator 9

3.4 Permitting and Regulatory Considerations 11

4.0 DESIGN EVALUATION 12

4.1 System Testing Limitations 12

4.2 Hydro Turbine 12

4.3 Solar Panels 12

5.0 CONCLUSIONS 13

5.1 Solar Panels 13

5.2 Hydro Turbine 13

6.0 RECOMMENDATIONS 14

7.0 MAINTENANCE 14

ACKNOWLEDGEMENTS 16

8.0 APPENDIX A: MECHANICAL LAB III REPORT 17

8.1 Introduction 17

8.2 Objectives 17

8.3 Apparatus, Equipment and Instruments 17

8.4 Theory 21

8.5 Procedure 21

8.6 Results 25

8.7 Conclusions 28

9.0 Appendix B: WIND TURBINE DATA SUMMARY 28

TABLE OF FIGURES

Figure 1 – Initial Design Energy flow block diagram 2

Figure 2 - Tag detection system 2

Figure 3 - Final Design electrical diagram 3

Figure 4 - Available Wind Power in Maine 6

Figure 5 – Ampair UW100 Water Turbine 8

Figure 6 – Solar panel in use at Witter Farm 9

Figure 7 – Ampair Dual input 24V regulator 10

Figure 8 - Morningstar Regulator 11

Figure 2 - Electrical Schematic 20

Figure 3 - Wind Tunnel Set Up 20

CONTRIBUTIONS

Adam Freund

Adam Freund was the point person for much of the technical work, especially the electrical work that was needed for the project. Adam did that majority of the work to figure out how to properly wire the wind turbine and data acquisition system for the RFID’s wind turbine testing.

Amanda Mayette

Amanda Mayette did much of the organization for the group, writing all of the initial reports, designing the group's website, and making sure important deadlines were met. She represented the group at the Engineering Expo and did the poster for the Open House presentation. Amanda was also the contact and spokesperson for the group for the first half of the project.

Matthew Sevey

Matthew Sevey did the majority of the group’s revisions and compilations of reports, as well as doing an initial website design. He was the main contact person between the group and Murray Callaway for the writing and editing of the group’s final report. He was responsible for working with the DEP to resolve the issue of permits. Matthew was also the spokesperson for the group for the second half of the project.

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1.0 INTRODUCTION

The Radio Frequency Identification (RFID) project was created to find an alternative energy solution to reliably power a fish tag detection system at a dam lacking AC power. The dam in question is located on the Piscataquis River in Dover-Foxcroft, ME, directly in the middle of town, and is owned by the town of Dover-Foxcroft. The project directly affected the University of Maine Wildlife Ecology Department. For this reason, Dr. Joe Zydlewski, from the Wildlife Ecology Department, and Dr. Michael Peterson from the Mechanical Engineering Department, teamed up to supervise the senior design group and its progress. RFID systems are used to detect and classify fish for long-term studies of populations. This project’s outcome helped the United States Geological Survey close one of the gaps in its ability to track the fish. Studies are being performed at dams across Maine, and the lack of availability of electricity at some sites impedes the progress of biologists.

In order to be considered viable, Dr. Joe Zydlewski and his team had to agree with the completed design and be ready to install the system on the Dover-Foxcroft Dam with or without the RFID group depending on timing. The design had to be able to charge the batteries while the batteries were powering the tag reader and be able to sustain periods of low power production due to the weather and the environment.

2.0 DESIGN DESCRIPTION

The main objective of the RFID project was to build a reliable power generation system to run a tag detection system similar to others that were already in use at several dams across Maine. In the tag detection systems, one to six antennas read tags implanted in fish as the fish pass through the fish ladder. The information read off the tags is then sent back to the system that often is located at the top of the fish ladder. Typically, the tag detection systems were plugged into an AC outlet to get the electricity needed to power the system.

In the initial energy system designed by the RFID group, electricity to power the system flowed from two chosen sources, a solar panel and a hydro turbine, into a dual input regulator. This regulator took the two energy inputs and combined them into a single energy output that charged a battery bank which powered the tag detection system. Figure 1 shows the energy flow in a block diagram for the initial design.

Figure 1 – Initial Design Energy flow block diagram

Figure 2 shows the tag detection system with its battery bank, charger, timer, and tag reader.

Figure 2 - Tag detection system

When it came time to test the system, the RFID group and Dr. Zydlewski decided to go with a system design that used four solar panels instead of the single solar panel and hydro turbine. This design required a new regulator that could handle the higher power output. The regulator also served as a single connection point for the solar panels, the battery bank, and the tag reading system. The final design electrical diagram is shown in Figure 3.

Figure 3 - Final Design electrical diagram

3.0 CONCEPT DESIGN PROCESS

3.1 System Energy Usage Requirements

The RFID project description asked for an alternative energy solution to be developed for use at a dam in Maine without AC power. In order to choose the power source(s) best suited to power the RFID system, the power requirements of the system had to first be determined. This was accomplished by visiting a running RFID system at the dam in Milford, Maine, as well as setting up a complete RFID system at the Deer Pens on the University of Maine campus. On both systems, various voltage and current readings were taken. Measurements were taken for different antenna configurations, sampling frequencies, and tag passing frequencies. Both typical and maximum power requirements for the system were determined using these measurements.

At the Milford Dam, the tag reading system was set up with three antennas and at a typical gain setting. The group measured the current drawn from the battery bank when the system was idle, so no tags were passing through the antennas. In this idle state, the system drew in 0.75A. Due to electronic noise in the system, the current fluctuated slightly and a maximum value for the current was measured to be 0.81A. The group also took the same measurements, but with one of the antennas unplugged to see the affect on the current. With one antenna unplugged, the system drew 0.66A.

Table 1 shows the values of current drawn from the battery bank that were measured at the Deer Pens system:

Table 1 – Electric current data from Deer Pens system

Test / Description / Current Drawn (Amps)
1 / System idle, one antenna, typical gain setting / 0.52
2 / Constant tag reading, one antenna, typical gain setting / 0.53
3 / System idle, one antenna, maximum gain setting / 0.70
4 / Constant tag reading, one antenna, maximum gain setting / 0.71
5 / System idle, no antenna, maximum gain setting / 0.40

It was observed that the number of antennas hooked up to the system did not significantly affect the current draw since the tag reader switches through the antennas at a set sample rate.

In order to be conservative with a power requirement estimate, a design current requirement of 1.0A was chosen. This was to account for factors such as

·  The variations in the current as it was being measured

·  Deviations in how the Dover-Foxcroft and other future systems are set up and run

·  Temperature effects

·  Battery voltage degradation

·  The need to power additional pieces of equipment such as modems

·  The fact that the Multiplex Transceiver user manual indicated that the unit can draw a peak current of up to 3.0A, which was never reached with the systems current configuration.

The system required a power input large enough to charge two 12V batteries in series; this resulted in a need for 24V DC. The system had a battery bank that consisted of two of these 24V series connected in parallel. Since the two-24V series were connected in parallel, a timer was used to change which set of batteries was powering the system every four hours. Electricity generation had to be constant, so the alternative energy system had to ensure that one set of batteries was powering the RFID system and one set of batteries was charging at all times.

Since it was critical that the tag reader take uninterrupted measurements, the group decided that slightly overdesigning the system was the best idea in order to ensure the stability of the system, since a regulator would prevent the batteries from overcharging. With the chosen design current of 1.0A and the required 24V from the tag reader, the power requirement of the system was 24W. Equation 1 shows how power is determined from a known current and voltage.

Power = Current * Voltage (1)

This value did not account for inefficiencies in charging or storing energy in the batteries, so the actual power produced by the renewable energy system needed to be higher.

3.2 Power Generation Options

The three main power generation options that were considered for this project were solar, wind, and water power, using a solar panel, wind turbine, and water turbine respectively. The three members of the group discussed many possibilities before it was decided that the best approach was to first examine the dam to determine if there were any location limitations. After the trip to Dover-Foxcroft, it was decided that the best option for this project was to use a hydro turbine to power the tag system.

Wind initially appeared to be a viable option due to the openness of the area and the strong continuous wind that was present during the group’s visit. In the end, a number of factors led to the decision to eliminate wind and to focus solely on a combination of water and solar power, even though the RFID group did have access to a free wind turbine. The RFID group tested the wind turbine so that Dr. Zydlewski and his team would have the necessary information in case they were to use the wind turbine in the future. Appendix A and B contain the lab report that the group wrote and the data collected from the wind turbine testing. Wind power proved to be the least reliable power source of the three options, especially for the area of intended use. The Dover-Foxcroft area, as well as most of inland Maine, had very low average wind speeds. Figure 4 shows the available wind power in Maine.

Figure 4 - Available Wind Power in Maine

Through research, it was found that the average wind speed in the area near the dam was typically below 5 m/s, which was not high enough to produce appreciable power. Another consideration in mounting a wind turbine at this particular site was that the dam was located in the center of town and was easily visible. A wind turbine mounted in this location could be seen as an “eyesore” to some.

The most constant of the three power sources on a daily basis was waterpower. Since the river flows at a relatively constant speed, it was a better choice for a reliable and predictable energy source. Since the RFID tag reader was located on a dam, the pressure head created by the dam could be utilized to obtain greater water speeds.

Solar power was the most common power source for this type of project for a number of reasons. Reasonable levels of solar radiation were found essentially everywhere, except for cloudy days; the patterns, durations, and intensities of sunlight were easily and accurately predictable. Solar panels have no moving parts, require minimal maintenance, are easy to install and have a long working life.