Domestic Solar Assisted Battery Charging Station with
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Transcript Domestic Solar Assisted Battery Charging Station with
Group Members: Taylor Lace, Ross Farmer, Xiaoyi Li, William Chou
Supervisors: Prof. Kropp & Prof. Wang
o
Optimize use of clean energy for residential setting
Uninterrupted power to household systems, despite outages
o
Management of intermittent solar power source
Reduction in power draw from grid, subsidized by clean solar
o
Intelligent use of large energy storage availability
(ex: electric vehicles)
Further progress towards efficient sustainability
o
Maximize power output from solar panels
o
Controlled charge/discharge of battery power
o
Generate pure AC sine wave from DC supply
o
Synchronize AC sine wave with grid
• Maximize photovoltaic power production
• Maintain a high quality output to the DC Bus
• Simulations on circuit performance done via
Matlab/Simulink
• Arduino Uno microcontroller
• Current sensing required by
MPPT
• Output filtering to hold DC
bus constant
Solar Cell 18V
Boost Output 50V
•
•
A constant 50V output achieved through the Boost circuit
from a 18V input
Feedback and self-adjusting MPPT via Arduino control
board
• Bi-directional Power flow,
linking Battery and Bus
• Lower (buck) the DC bus
voltage to ideal charging
conditions for battery
• Increase (boost) the
outgoing battery voltage to
maintain constant DC bus
voltage, leading to house
• Isolated controls for driving
buck/boost levels and
switching
• Power flow from low voltage battery
towards higher voltage DC bus
→
Power Flow
140
• Boost capabilities relative to amount
of inductance and capacitance
Input Voltage
120
25KΩ
100
Voltage (V)
• PWM signal from programmable
Arduino board used to a control
output voltage via isolation circuit
50KΩ
80
100KΩ
60
200KΩ
40
500KΩ
20
1MΩ
0
90
70
50
Duty Ratio
30
10
2MΩ
5MΩ
• Large boost voltages are easily
achieved at output with exchange
of inductors
o Power flow from high voltage
DC bus (grid) to lower voltage
battery charging
o Same control scheme as boost
mode
←Power Flow
o Significant voltage dropping
would be required for real
application battery charging
from ≈120V input
25
Voltage (V)
o Voltage and Current sensors
relaying information to Arduino
control board could allow for
instantaneous self-adjustment
of circuit
30
20
Input
Voltage
15
10
Output
Voltage
5
0
0
3
7
13
20
30
Duty Cycle
40
50
65
Capturing grid frequency and amplitude feed into the
programmable Microprocessor
Programming the microprocessor with control techniques
including PLL, PI controller and Park Transformation
Microprocessor processes the real time data and
generate PWM waveform
Toggle the GPIO in of the microprocessor to generate
sinusoidal PWM signal
Hardware Issue:
o
Software Issue:
o
Arduino board to ZedBoard
Software change-over complications
Challenges:
o
Configure peripheral of ZedBoard in Xilinx XPS
o
Write constraint files
o
Time function on ZedBoard
o
Clock & Interrupt
System On A Chip(SoC)
USB UART
ARM
Processor:
1GHz
A-D
converter
JTAG
Unipolar
PWM Signal
GPIO: 3.3 V DC
ZedBoard
Full Bridge Inverter
Unipolar PWM Sine Wave
• Comparing sine wave to a triangle wave
to determine when to switch
• Only 1 MOSFET in each leg is active at
any given time
LC Low Pass Filter
• Filter out the high
frequency triangle
wave
• Cut off frequency
close to desired 60
HZ and well below
triangle to allow high
attenuation
Sine Wave!
Challenges…
Increasing gate voltage
Sizing of inductor and capacitor
Measurement for feedback control
Increase output voltage
…Solutions
Voltage Sensor
Optocouplers
Current Sensor
• Single Phase Inverter
Increase Output voltage
• Bi-directional Buck Boost converter:
Switching for instantaneous mode change between modes
Automation of the switching circuit for self adjustment.
• Inverter Controller
Debug the controller C code
Adjust Frequency to constant 60Hz
• MPPT Controlled Boost Converter
Upgrade current sensor
Increase efficiency of MPPT algorithm