Transcript Solar Charge Controller Schematic

Solar Powered
Golf Cart
Group 9
Jake Bettis
Jacob Krueger
Matthew Roland
Matt Tourtelot
With Support from:
Motivation
● Rapid growth in renewable energy, such as
solar power, has caused a huge increase in the
demand for engineers that know how to utilize
these alternative sources of energy
● With our project we are able to design and
create an environmentally friendly vehicle while
gaining first-hand knowledge and experience in
a growing industry
Goals
To create an energy efficient golf cart that is capable of
running on solar power and external outlet. A touch-screen
display will give the user options for different energy
modes, navigational help, and status of golf cart
Objectives
● Harvest energy from sunlight to power electric motor and onboard
electronic systems
● Three modes of energy operations
o standard, max performance, max efficiency
● Power monitoring system to display battery levels and check for battery
storage defects
● User touch-screen display
o Provides navigational map interface
o Allows users to change cart’s operating mode
o Displays cart’s current speed, current mode, and battery charge
remaining.
Objectives
Energy Modes
● Standard mode: A normal acceleration ramp will be used for this setting
● Max Performance: The motor controller will ramp up the speed almost
instantly
● Max Efficiency: The motor controller will ramp up the speed very slowly
The biggest power drain on the cart is acceleration so this was controlled to
save energy
Specifications and Requirements
1. Must have a top speed of at least 15 mph
2. Must have 3 modes of operation which can be controlled by
user
3. Must run off of a 36V or 48V battery storage bank
4. Batteries must be able to charge from solar panels or wall outlet
5. Must have a touch-screen display for user information
6. Must provide navigational aid to user
7. Must provide power mode options and current speed
Budget
Part
Estimated Cost
Actual Cost
Motor Controller
$600
$550
Batteries
$600
$550
Charge Controller
$150
$100
Microcontroller(s)
$120
$140
Touch-Screen Display
$120
$70
Sensors
$150
$50
Misc.
$100
$400
PCB Fabrication
$0
$265
Total
$1,840
$2,125
Power System Components
● Solar Panels and Wall Outlet
o
provide power for motor and onboard electronics
● Solar Charge Controller
o
o
Regulate power inputs from solar panels the batteries
Implement MPPT algorithm to keep from overcharging and
damaging the batteries
● Battery Bank
o
provides 36V battery supply
Power System Overview
5V
DC/DC
Regulator
Wall Outlet
Battery Bank
Solar Panels
Solar Charge
Controller
+36 V
Touchscreen
Display
Oddroid
C1
Motor
Power
Board
3.3V
DC/DC
Regulator
Motor
Controller
Solar Panel Electrical Specs
Project design implements two panels connected in series.
Unit
Quantity
Maximum Power Pmax
250 W
Voltage at maximum power point Vmpp
30.7 V
Current at maximum power point Impp
8.15 A
Open Circuit Voltage Voc
37.7 V
Open Circuit Current Ioc
8.72 A
Operating Temperature
-40° C to +85° C
*Specs are based on single panel at standard test conditions
Battery Supply
● 36V battery bank that will power motor and all
onboard electronics
● Flooded lead-acid, deep cycle batteries
o Able to withstand deep discharge cycles
and have a long lifetime
● At 25A output batteries can last for 474
minutes, and 122 minutes at 75A
Battery Specs
U.S. 2200-XC2 Deep Cycle Lead-Acid battery
Unit
Quantity
Voltage
6V
Amp hours (20 hour rate)
232 Ah
Minutes at 75 Amps
122 min.
Minutes at 56 Amps
179 min.
Minutes at 25 Amps
474 min.
Wet Weight Lbs.
62 Lbs.
Battery Specs
●
Rate of discharge
○ Batteries need to
be able to operate
for as long as
possible while
supporting
different energy
modes
○ Consider current
vs. discharge time
Charge Controller
●
●
●
●
Goal is to regulate voltage and current
from solar panels to the battery, to prevent
overcharging
Will implement a maximum power point
tracking (MPPT) algorithm
○
Finds the maximum power point on
the I/V curve and tracks that point as
sunlight conditions vary
Works as DC to DC converter
○
Outputs GPS coordinate information
to the microcomputer
Design is based off of Texas Instruments
TIDA-00120
Solar Charge Controller Schematic
• Block diagram of
Solar Charge
Controller
System
• SM72295:
Photovoltaic Full
Bridge Driver
• INA271 : voltage
output, current
sense amplifier
Solar Charge Controller Schematic
• MSP430F5132:
ultra-low power
mixed signal
microcontroller
• LM5019: 100V
buck regulator
• TLV70433: low
dropout regulator
(LDO)
MPPT Algorithm
• Perturb and Observe
•
Method is to modify the
operating voltage or current
from PV panel until you obtain
maximum power from it
Touchscreen Display System Objectives
● Provide users with straightforward navigation around
the UCF campus via GPS location
o Navigational map will be interactive and contain
certain customizable features
● Display the golf cart’s current speed and operating
mode
● Allow users to easily switch between available cart
operating modes
Touchscreen Display System Components
● Microcomputer
○
○
Provides platform for Android Operating System
Processes GPS and display signal input and output
● GPS PCB module
○
Outputs GPS coordinate information to the
microcomputer
● Touchscreen Display
○
○
Provides user with display of the Android Application
Supplies microcomputer with user input
Touchscreen Display Data Flow Chart
Microcomputer
ODROID C1
Raspberry Pi
Market Price
$38
$35
CPU
1500 MHz CortexA5
700 MHz
ARM1176JZF-S
Video Outputs
Micro-HDMI
HDMI and
composite video
Power Source
0.8mm x 2.5mm
5V jack
5V via MicroUSB
or GPIO header
ODROID C1 Features Implemented
● Android Runtime Environment compatibility
o
o
Allows for the creation of a specialized Android
Application
Easy Debugging
● HDMI video signal output
o
Allows video signal to be sent to the touch screen
display while freeing up the USB input for the touch
screen’s user input signals
Touchscreen Display
HDMI 4 Pi: 5”
Display w/ Touch
and Mini Driver 800x480 HDMI
Tekit 619AHT 7”
LCD Monitor
Market Price
$79.95
$179.98
Screen Size
4.8” x 3.0”
8.23” x 5.7”
Resolution
800 x 480
800 x 480
Display Ratio
16:10
16:9
Contrast
300:1
500:1
MTK3339 GPS Module
● Sends GPS data
pertaining to the current
user position to the
ODROID C1
● 10 Hz update frequency
● Accurate to about 3
meters
GPS Module - PCB Schematic
GPS Module - PCB Design
GPS Module - PCB
Android Application Development
● Developed within the Eclipse IDE using the latest
Android SDK
● Many other inherent features of Java are used
throughout the application design
● Tested for accuracy and reliability on every design
prototype iteration
Android Application Class Diagram
UCF EzNAV Main Menu
● Very simple, intuitive
interface
● The only screen that
gives access to every
created class
● Each button takes the
user to a new screen
within the app
Navigate Screen
● Interactive Google Maps
Fragment
● “My Location” button
and functionality
● Map markers for
reference and building
information
● License key for Google
Maps API obtained
through Google Inc.
Cart Status Screen
● Features updating data
fields for cart information
o Uses signals from
the Motor Controller
and GPS module to
generate values
● Interface buttons that
allow users to change
the cart’s operating
mode
Motor Controller Overview
● Pre-charge circuit
prevents inrush current
to motor controller
● Potentiometer pedal
provides a voltage from
1.45-1.92
● Direction switch
removes need for HBridge
Power Board
Power Board Schematic
● High current MOSFET’s
●
On-Resistance of 1.45mΩ
● Capacitance
● Flyback diodes
Motor Controller Logic
Pedal
● Potentiometer over ITS
Modes of Operation
● Mode determined
by user from touch
screen
Progress
Chart Title
Total
Design
Research
Prototyping
Testing
0%
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100%
120%
Questions?