Transcript Solar Glider - Txstate - Texas State University

Put a picture
of what was
created here
Sponsor: Name & Affiliation
Faculty Advisor: Name
Team Members
Vinh Diep
Francisco Saavedra
Matthew Bringhurst
Project Manager
& Embedded Systems
Engineer I
Test Engineer
& Embedded Systems
Engineer II
Design Engineer

Project Overview

Design Approach

Results

Future Work
GOALS OF PROJECT
STRETCH GOALS

Create Low powered Sensing Node

PCB Design

Capture both AC/DC Voltages and
Currents from Solar Panel or Wind
Turbine systems

Recharge circuit by Solar
panel or wind turbine

Wirelessly transmit processed data
through TWP and IoT Gateway to the
Proximetry Cloud Server

Updates values every 15 seconds to
Proximetry
The problem:
o
o
o
Wired Systems
Expensive
No complete system in place
Why is this important?
o
o
Remote monitoring
Scalable – Reduction of cost

Continued collaboration between NXP and Texas
State University

Develop a prototype and demonstrate
functionality using NXP development tools
(Kinetis KW24 TOWER board etc.)

Provided technology and technical advise
I-V Sensor Node Device Cost
We planned that unit would cost
under $25. The unit actually
cost $49.23. The main I-V
sensor cost $39.95
We’ve spent over $300 in
rookie mistakes:
• Understanding certain
components (ex. shunt)
• Testing out different versions
of analog design
Items
Cost
MAX4194 (2)
$5.38
1N4004 (6)
$.78
10k resistor (5)
$.66
330k resistor (1)
$.47
3.65k resistor (1)
$.61
100mA fuses (3)
$.66
Fuse Holders (3)
$6.78
PCB Board (1)
$15
50A /.075V Shunt (1)
$5
Enclosure (1)
$7
Terminal Strip (1)
$2.89
Voltage Regulators (2)
$4
Total
$49.23

16 bit MKW24 MCU and Tower Board Development
System

Thread Wireless Protocol

Build the device based on Wind Turbine and Solar
panel Voltage and Current maximum output 300V, 50A

Single Supply Operation

Design and simulate Analog circuit with a Spice Program

Test for Linearity

Implement ADC for Voltage, Current, and DC Offset

Data Correction

Implement moving Average for True RMS

Utilize thread library to implement TWP and send data to
Proximetry GUI

Device is fully functional with minimal error

High Voltage AC and DC test, low DC current tested

Readings are in TRUE RMS

Dynamic DC offset calibration

Frequency of Proximetry were within reason

Accomplished Stretch Goal: PCB assembled, test, and
enclosed. Battery and MKW24 also enclosed.
3 ADCs for Voltage, Current, and DC offset, respectively pins 80, 79, 78 on the MKW24
DC Input Voltage
DCExpected
Input Voltage
Digital Value
Actual Digital Value
% Error
0.5007V
10769
0.5007V
10758
0.1022
1.5020V
32262
1.5020V
32255
0.0217
2.5009V
53787
2.5009V
53810
0.0427
Expected Digital
Value
Actual Digital Value
% Error
10769
10758
0.1022
32262
32255
0.0217
53787
53810
0.0427
1) Stable DC Offset Voltage
2) Convert the digital representation into Voltages (1-1
ratio)
3) Plot a regression and find the slope and offset, this
will be used for data correction.
4) Check Proximetry values against
Voltmeter/Ammeter
•
DC offset is used in data correction calculations
•
Changes in reference voltage over time will cause an increase in error
•
Our Solution: Dynamic reference voltage utilizing another ADC
High Voltage Test: DC
proximetry = 0.2421 + 1 .005 multimeter
200
S
R-Sq
R-Sq(adj)
0.1 9281 1
1 00.0%
1 00.0%
Sensing Type
Full Range % Error
Voltage DC
0.1318
Voltage AC
0.9301
Current DC
0.49
Current AC
TBD
1 00
50
0
0
50
1 00
1 50
200
8808A Multimeter VDC
High Voltage Test: AC
Proximetry Voltage = 2.088 + 1 .004 8808A Multimeter
1 60
DC Test – up to 200V,
up to 3.18A
AC Test – up to 150VRMS
*AC Current is to be tested
S
R-Sq
R-Sq(adj)
1 40
1 20
Proximetry VRMS
Proximetry VDC
1 50
1 00
80
60
40
20
0
0
20
40
60
80
1 00
8808A Multimeter VRMS
1 20
1 40
1 60
0.0827578
1 00.0%
1 00.0%
Time Stamps
Time Elapsed(s)
[04:33:48]
0
[04:34:03]
15
[04:34:18]
15
[04:34:33]
15
[04:34:48]
15
[04:35:03]
15
[04:35:18]
15
[04:35:33]
15
[04:35:48]
15
[04:36:04]
16
[04:36:19]
15
[04:36:34]
15
[04:36:49]
15
* Output from Putty

Average Power Consumption testing to improve life of the battery.

Our second stretch goal was create a recharge circuit

User controlled updating to control the frequency to the Proximetry Servers.

High Current sampling to properly improve data correction factor for AC/DC
Current

Research on Wind Turbine and Solar Panel abnormal behaviors/errors to
improve error handling

Dr. Kevin Kemp (NXP) – Technical advisor and Sponsor

Dr. William Stapleton (Texas State) – Faculty advisor

Dr. Rich Compeau (Texas State) – Faculty advisor

Sarah Rivas – Texas State Gatekeeper