A New Single Phase PV fed Five Level Inverter
Topology connected to the Grid
OCTOBER 08, 2010
Presentation By
Mr. M.Kaliamoorthy,
Assistant Professor
Department of Electrical and Electronics Engineering
PSNA College of Engineering and Technology
Dindigul, Tamilnadu-624622
Tel: 9865065166
E-Mail: kaliasgoldmedal@gmail.com,kalias_ifet@yahoo.com
Website:www.kaliasgoldmedal.yolasite.com
Paper Number : 370
The Journey of Thousand Miles Begins with a single step
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Objectives of This Paper
To design a new Multilevel Inverter Topology for Photovoltaic Applications
with minimum number of Switches
To Design a Control algorithm for New Topology with minimum carrier signals
To suggest a Novel Carrier for Multilevel inverters
To compare the novel carrier with Conventional Triangular Carrier
(Comparison based on Ma and Mf with THD)
Low aim is a crime- Diode-John Ambrose Fleming-1904
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL WORKING PRINCIPLE
Model a Drop, To know the power of the OCEAN- Zener Diode –Clarence Melvin Zener-1915
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING
From the figure
I  I L  I D    (1)
Where I=Output Current In Amps
Il=light Current Or Photo Generated Current In Amps
ID= Diode Current in amps
Workship the creator not his creation- Edmond Becquerel ,1889 Electricity From Sun
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
By Shockley equation, current diverted through diode is

 U  IRs
I D  I o exp 
 nkT / q

Where
 
  1
 
Io= Reverse Saturation Current
n= Diode Ideality Factor
K=Boltzmann’s Constant
T= Absolute Temperature
q= Elementary Charge
For silicon of 250C nkT/q=0.0259 volts=α

 U  IRs  
I D  I o exp 
  1
 
 

Reading is an adventure that never ends- Photo Voltaic Cell- Russell Ohl-1903
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
Substituting above equation in equation (1) we get
  U  IRs  
I  I L  I o exp 
  1    (2)
    
Where α=nkT/q is known as Thermal Voltage Timing Completion Factor
The four Parameters IL,Io,Rs and α need to be determined to
Study the I-U characteristics of PV cells
Believing in yourself is the first step to success- Lead Acid Battery- Raymond Gaston Plante-1859
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
LIGHT CURRENT IL determination


IL 
I L,ref   I ,SC Tc  Tc,ref 
ref
Where 
 irradiance (W/m 2 )
ref  reference irradiance (1000 W/m 2 is used in this study)
I L,ref  Light current at reference condition (1000 W/m 2 and 25 0 c)
Tc
 PV cell temperatu re
Tc, ref  Reference Temperatur e (250 C is used here)
 I , SC  Temperatur e coefficien t of the short circuit current (A/ 0C )
Both I L,ref and  I,SC can be obtained from manufactur er data sheet
Look at your strengths and not your weaknesses- SCR-General Electric (GE)-1958
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
SATURATION CURRENT IO determination
 egap N s  Tc ,ref  273 
 Tc ,ref  273 
 exp 
1 

I o  I o,ref 
Tc  273 
 q ref 
 Tc  273 
Where I o,ref  Saturation current at the reference condition (A)
3
e gap
 Band gap of the material (1.17eV for Si materials)
Ns
 Number of cells in series of the PV module
q
 Charge of the electron (1.60217733 x 10-19 C )
 ref  The value of  at the reference condition
U oc,ref
 U

I o,ref  I L,ref exp   oc,ref 
  ref 
 The open circuit vo ltage of the PV module
at the reference condition( V) (Will be provided by manufactur ers)
Success is a journey, Which has no Destination- Alternator-Nikola Tesla-1891
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
Calculation of α
2U mp,ref  U oc,ref
 ref 
I sc,ref
I sc,ref  I mp,ref
 I mp,ref
 ln 1 

I sc,ref





Where
U mp,ref  Maximum power point volt age at the reference condition (V)
I mp, ref  Maximum power point current at the reference condition (A)
I sc,ref
 Short circuit current at the reference condition (A)
 is a function of temperatu re, which is expressed as

Tc  273
 ref
Tc ,ref  273
There is no age bar for learning- Electric Chair-Harold P.Brown-1888
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODELING Cont…
Calculation of Series Resistance Rs
Some manufactures provide value of Rs, if they do not provide
It can be calculated as follows

I mp , ref 

  U oc, ref  U mp , ref
 ref ln 1 
I sc, ref 


Rs 
I mp, ref
Rs is taken as constant here
Thermal Model of Photovoltaic cell
C pv
C pv
dTc
U xI
 kin, pv 
 K loss Tc  Ta 
dt
A
 The oveall heat capacity per unit area of the PV cell/Modul e [J/( 0 c.m 2 )]
K in, pv  Transmitta nce absorbtion product of PV cells
k loss
 Overall heat loss coefficien t[ W/( 0 c.m 2 )]
Ta
 Ambient te mperature( 0 c)
A
 Effective area of the PVcell/ Module(m 2 )
Knowledge is the antidote to fear – Electric Distribution System –Thomas Alva Edison - 1882
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODEL PARAMETERS
IL,ref(ISC,ref)
2.664 A
αref
5.472 V
Rs
1.324 Ω
Uoc,ref
87.72 V
Ump,ref
70.731 V
Imp,ref
2.448 A
Φref
1000 W/m2
Tc,ref
250c
CPV
5 X 104 J/ (0c.m2)
A
1.5m2
Kin,pv 0.9
Kloss
30 W/ (0c.m2)
Present life is better than life coming in future – Robot- Jacques de Vaucanson-1738
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODEL IN MATLAB/SIMULINK
Be willing to accept temporary inconvenience for permanent improvement –Dynamo-Michael Faraday-1832
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PHOTOVOLTAIC CELL MODEL IN MATLAB/SIMULINK
Better safe than sorry –Analog Storage Oscilloscope- Hughes-1957
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
CHARACTERISTICS OF PV CELL AT CONSTANT
CELL TEMPERATURE
Voltage Vs Power Characteristics
Voltage Vs Current Characteristics
250
4.5
1400 W/Sq.M
1600 W/Sq.M
1200 W/Sq.M
1000 W/Sq.M
800 W/Sq.M
200
4
3.5
Current in secs
Power in Watts
3
150
100
2.5
2
1600 W/Sq.M
1400 W/Sq.M
1200 W/Sq.M
1000 W/Sq.M
800 W/Sq.M
1.5
1
50
Constant Cell Temperature 25 deg Centigrade
0.5
Constant Cell Temperature of 25 deg Cent
0
0
10
20
30
40
50
Voltage in Volts
60
70
80
0
0
10
20
30
40
50
Voltage in Volts
60
Distance lends enchantment to the view –CRO- Karl Ferdinand Braun- 1897
2010 IEEE International Conference on Communication Control and Computing Technologies
70
80
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
CHARACTERISTICS OF PV CELL AT CONSTANT
IRRADIANCE
Voltage Vs Current Characteristics
Voltage Vs Power Characteristics
3.5
160
50 deg C
75 deg C
100 deg C
125 deg C
150 deg C
3
140
120
2.5
100
Power In Watts
Current In Amps
50 deg c
75 deg c
100 deg c
125 deg c
150 deg c
2
1.5
80
60
1
40
Constant Irradiance of 1200 W/Sq.M
0.5
0
0
20
10
20
30
40
50
Voltage in Volts
60
70
80
0
Constant Irradiance of 1200 W/Sq.M
0
10
20
30
40
50
Voltage in Volts
Everyone wants to go to heaven but nobody wants to die - Megger – Evershed - 1905
2010 IEEE International Conference on Communication Control and Computing Technologies
60
70
80
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
New PV fed Multilevel Inverter
Everything comes to him who waits -Ammeter – Edward Weston -1886
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Operation of Five Level Inverter with Auxiliary Switch
Vdc
2
S3
D2
S5
D4
S2
D3
Vdc
2
D5
Vdc
2
S3
D2
S5
D4
S2
S4
D3
S6
D5
Vdc
2
S4
Fish and guests smell after three days - Digital Multimeter –Fluke Electronics- 1969
2010 IEEE International Conference on Communication Control and Computing Technologies
S6
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Operation of Five Level Inverter with Auxiliary Switch
Vdc
2
S3
 VPV

pv 2
D2
S5
Vdc
2
D4
S3
D2
S2
D3
S5
D4
S2
D5
D3
Load
Vdc
2
D5
Vdc
2
S4
S6
S4
History repeats itself - Electrolytic capacitor- Julius Edgar-1928
2010 IEEE International Conference on Communication Control and Computing Technologies
S6
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Comparison of Different Carrier Waves
One can never consent to creep when one feels an impulse to soar – Electromagnetism –Maxwell-1865
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
New Five Level Inverter with Auxiliary SwitchA dual Reference Modulation Technique
Don’t sit like a rock work like a clock- Fluorescent Lamp –Edmund Germer - 1926
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PWM Strategy and Operating Principle
Modulation index Ma for five-level PWM inverter is given as
Ma 
Am
2 Ac
Where Ac is the peak-to-peak value of carrier and Am is the peak value of voltage
reference Vref. Since in this work two reference signals identical to each other are
used, above equation can be expressed in terms of amplitude of carrier signal Vc
by replacing Ac with Vc and Am=Vref1=Vref2=Vref
M 
Vref
2Vc
One today is worth than two tomorrows- Fuel Cell- Francis Thomas Bacon -1932
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
PWM Strategy and Operating Principle
Switches S2–S4 will be switching at the rate of the carrier signal frequency, while
S5 and S6 will operate at a frequency equivalent to the fundamental frequency.
A great talker is a great liar - Hall Effect- Edwin Hall -1879
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
CLOSED LOOP CONTROL SYSTEM
A man is as old as he feels - Hybrid Vehicle –Ferdinand Porsche-1899
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Maximum Power Point Algorithm
Be willing to accept temporary inconvenience for permanent improvement- Logic gates-Charles Babbage -1837
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
Dual Reference and Carrier Comparison
Believing in yourself is the first step to success- Neon Lamp –Georges Claude-1910
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
Switching Signals to S2 and S3
A hungry man is an angry man -Pager-Al Gross-1949
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
Switching Signals to S4 and S5
Discretion is the better part of valor -Piezoelectricity-Pierre Curie-1880
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
Switching Signals to S6
Lightning never strikes twice in the same place -Relay-Joseph Henry-1835
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
OUTPUT VOLTAGE WITH M ,D < 0.5
INVETER CURRENT WITH M ,D < 0.5
Money makes the world go round - Thermo Electricity –Thomson Johann Seebeck-1821
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
OUTPUT VOLTAGE AND ITS
FUNDAMENTAL WITH M ,D > 1.0
INVETER CURRENT WITH M ,D > 1.0
Never judge a book by its cover - Radio Guglielmo-1901
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
OUTPUT VOLTAGE AND ITS
FUNDAMENTAL WITH 0.5 <M ,D > 1.0
INVETER CURRENT WITH M ,D > 1.0
Never put off until tomorrow what you can do today - Remote Control –Nikola Tesla-1898
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
SIMULATION RESULTS
Selected signal: 75 cycles. FFT window (in red): 9 cycles
Selected signal: 20.7 cycles. FFT window (in red): 8 cycles
2
200
0
0
-200
1.34
1.36
1.38
1.4
1.42
Time (s)
1.44
1.46
1.48
-2
1.5
0.25
Fundamental (50Hz) = 193.7 , THD= 8.28%
0.3
Time (s)
0.35
0.4
Fundamental (50Hz) = 1.997 , THD= 7.01%
6
Mag (% of Fundamental)
Mag (% of Fundamental)
4
3
2
1
0
0
5
10
Harmonic order
15
5
4
3
2
1
0
20
Harmonic Spectrum of Voltage With 0.5 <M ,D > 1.0
With out filters
0
200
400
600
Frequency (Hz)
800
1000
Harmonic Spectrum of Current With 0.5 <M ,D > 1.0
Without filters
No one can make you feel inferior without your consent –Regenerative Circuit-Edwin Armstrong-1914
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
CONCLUSION
This paper presented a single-phase five-level inverter with a dual reference
modulation technique for PV application. The dual reference modulation technique
involves comparing two reference signals identical to each other except for an
offset equivalent to its carrier signal, with a rectified inverted sine carrier signal
to generate PWM switching signals for the switches. The circuit topology, control
algorithm and operational principle of the proposed inverter were analyzed in detail.
The results show that the THD of the five-level inverter is much less than that of the
conventional three-level inverter. Furthermore, both the grid voltage and the grid
current are in phase at near unity power factor.
Opportunity never knocks twice at any man's door - Electron –Joseph John –Thomson-1897.
2010 IEEE International Conference on Communication Control and Computing Technologies
Presented By: M.Kaliamoorthy,AP,PSNACET,EEE
Success is a journey, Which has no Destination
2010 IEEE International Conference on Communication Control and Computing Technologies