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