Students:Thomas Carley Luke KetchamBrendan Zimmer
Advisors:Dr. Woonki NaDr. Brian Huggins
Bradley UniversityDepartment Of Electrical Engineering
2/28/12
Presentation Outline
Brief Summary of Project GoalsFunctional Description, System Block
Diagram, and Performance Specifications Implementation, Construction, and TestingSchedule and Milestones
Project Summary
Supplies DC and AC PowerPhotovoltaic ArrayBoost Converter to step up PV voltageMaximum Power Point Tracking DC-AC converter for 120Vrms 60HzLC filter
System Block Diagram
Photovoltaic Boost Converter Inverter
DSPBoard
LC Filter
DC Output AC Output
Grid
DC Subsystem Requirements
The boost converter shall accept a voltage from the photovoltaic cells.
– The input voltage shall be 48 Volts.– The average output shall be 200 Volts +/- 25 Volts.
The voltage ripple shall be less than 20 VoltsThe boost converter shall perform maximum
power point tracking.– The PWM of the boost converter shall be regulated based on
current and voltage from the PV array.– The efficiency of the MPPT system shall be above 85%.
AC Subsystem Requirements
The AC side of the system shall invert the output of the boost converter.
– The output of the inverter shall be 120 Volts RMS.– The output shall be 60Hz +/- 0.1Hz.
The inverter output shall be filtered by a LC filter.– The filter shall remove high switching frequency harmonics.– Total harmonic distortion of the output shall be less than
15%.
Boost Converter
10
1000u
0 240.50000
100u 636
VA
Test Boost Converter
10V to 30V
Boost Converter
0 0.02 0.04 0.06 0.08 0.1Time (s)
0
10
20
30
40
50
60
V1
Output Voltage (V)
Boost Converter
0 0.02 0.04 0.06 0.08 0.1Time (s)
0
-2
2
4
6
8
10
I1
Output Current (A)
Boost Converter
48
4000u
50000 0 274.
100u 200
VA
5
V
48V – 200V
Soft Start
Boost Converter
0 0.05 0.1 0.15 0.2 0.25Time (s)
0
100
200
300
400
V1
0 0.05 0.1 0.15 0.2 0.25Time (s)
0
50
100
150
200
250
300
V1
Without Soft Start (V) With Soft Start (V)
Boost Converter
0 0.05 0.1 0.15 0.2 0.25Time (s)
0
-10
10
20
30
40
I1
0 0.05 0.1 0.15 0.2 0.25Time (s)
0
-5
5
10
15
I1
Without Soft Start (A) With Soft Start (A)
Boost Converter
Output Voltage Inductor Current
Boost Converter Future Work
RC snubber circuit to reduce voltage spikes Adjustment of load resistor value Adjustment of output capacitor Implementation of soft start either through
– Switched Resistor– Slowly increasing duty cycle with DSP
Power Supplies
120Vrms 60Hz input from wall 15V, 5V, and 3.3V output Consists of Transformer, Diode Rectifier,
470uF capacitor, and voltage regulators Needed for Gate Drivers, Op Amps, Sensing
ICs, and other logic devices
110
169.760
C470u
LM7815AC15V Regulator
LM78L05AC5V Regulator
LM1117T-3.33.3V Regulator
Diode Rectifier
Power Supply
Power Supply
Implementing MPPT with DSP
Voltage Divider Current Sensor Simulink Modeling for TMS320F2812
Voltage Divider
OP484
+5V
+3.3V0 to 12V
20.5k
7.5k
50k
0.01uF
100
1000pF
VADC
+3.3V
Current Sensing
Current Sensor thru current
Current Sensor Vout
0.001 A 2.513 V
0.1 2.517
0.2 2.521
0.3 2.525
0.4 2.529
0.5 2.532
0.6 2.536
VAV
A V AveI Ave /0869565.26
30038.01.0
..
Current Sensing Circuit
1
2
3
4
8
7
6
5
ACS712Vout
+5V
I+
I- 0.001uF
0.01uF
Simulink Model
2Ipv
1Vpv
3/4096
convert to Volts1
3/4096
convert to Volts
26.08696
Volts to AmpsSubtract
C281x
PWM
W1
PWM
MPPT_V
MPPT_I
F2812 eZdsp
60
Duty Cycle
double
Data Type Conversion1
double
Data Type Conversion
ADC input from Voltage divider
ADC input from Current sensor
C281x
ADC
A0
A1
ADC
2.513
2.513V
Single Phase Inverter
Inverter H-Bridge and gate drives Tested with complementary PWM signals
To do: Add isolation Add logic compatibility circuitry
Inverter Experimental Results
Vsource = 10 V Rload = 496 Ω
Sinusoidal PWM
The magnitude of a triangle carrier signal is compared to a sinusoidal reference
If Vreference > VcarrierPWM signal = high
If Vreference < VcarrierPWM signal = low
Sinusoidal PWM – Simulink
SPWM – Simulink Results
LC Filter
Second order LC filter transfer function:G(s) = 1/(L*C*s^2+1)
LC Filter - Simulation
Simulation Results
Unfiltered frequency spectrum
Filtered frequency spectrum
Schedule and Milestones
Luke Brendan Tom3/1 Simulink MPPT Snubber for Boost Inverter DSP
3/6, 3/8 Inverter DSP3/13, 3/153/20, 3/22 Inverter DSP3/27, 3/29
4/3, 4/54/9
4/10, 4/124/17, 4/19
4/244/26, 5/1
5/7
Extra time
MPPT with smaller Boost Converter
Boost Converter and Inverter IntegrationMPPT and Boost with 2 PV's
Boost Converter and Inverter Integration
Spring Break
Final Project Oral PresentationsFinal Project Report Due
Draft of Final Project Report
Organize Information for Oral PresentationOral Presentation Prep
Questions?
PV data collection
• Mostly sunny, with a high near 36. West southwest wind between 8 and 11 mph, with gusts as high as 15 mph.
BP350J collection Feb 9, 2012
0
2
4
6
8
10
12
14
16
18
20
8:31:12 8:38:24 8:45:36 8:52:48 9:00:00 9:07:12 9:14:24 9:21:36 9:28:48 9:36:00 9:43:12
Time of Day
Load
Vol
tage
[V] a
nd C
urre
nt[A
]
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Load
Pow
er[k
W]
Load_VLoad_ALoad_W
Boost Converter
Current Before Diode Drain Voltage
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