Lossless DC–DC Boost Converter With High Voltage Gain For PV ...

Asian Transactions on Engineering (ATE ISSN: 2221 - 4267) Volume 02 Issue 04
Lossless DC–DC Boost Converter With High
Voltage Gain For PV Technology
Falah Al Hassan*, Vladimir L. Lanin
*Electrical and Electronics Engineering Department, Eastern Mediterranean University, Famagusta,
Cyprus, Email: falahalzobe@yahoo.com
Electronic Technique and Technology Department, Belarus State University of Informatics and Radio
electronics, Minsk, Belarus, Email:vlanin@bsuir.by
Abstract— The demands of PV technology with high performance
is very interesting alternative on supplement the electric system
generation, due to the persistent cost reduction of the overall
system a lot of works have been done during the design and
implementation of high efficiency DC-DC converters applicable
in PV . This paper proposes for improving the power-conversion
efficiency and to obtain high voltage gain by reducing voltage
stresses at a switch node of boost converter by using snubber cell
which consists of inductors, capacitor, as well as diodes. In the
proposed converter, two inductors with same level of inductance
are charged in parallel during the switch –on period and are
discharged in series during the switch-off period. Moreover the
paper discusses the theoretical analyses in detail and present
experimental result. Finally The improved boost converter
topology was built in the laboratory to verify the performance
with input voltage 15V to out 130 V and the typical operation
frequency 30KHZ to get hold of efficiency between (90-94)%.
Semiconductor power devices need snubber circuits
because they have a limited safe operating area at turn-on and
turn-off. The objective of a snubber circuit is to help the
device during the switching transitions to survive the voltage
and the current stresses. These stresses are due to the
interruption of the current at turn-off and to the collapse of the
voltage at turn-on. Numerous topologies of snubber circuits
are available in the literature [4]-[6].
keywords— PV,DC-DC boost converter, high voltage gain
snubber circuit, high efficiency.
P
I. INTRODUCTION
hotovoltaic PV power systems are one of today’s fastest
growing renewable energy technologies. Solar cells, which
are the foundation of PV systems, convert the energy in
sunlight directly into electricity. A number of solar cells
electrically connected to each other and mounted in a support
structure or frame is called a photovoltaic module. Modules
are designed to supply electricity at a certain voltage. Multiple
modules can be wired together to form an array [1]-[3].
In distributed generation (DG) systems, interfacing
photovoltaic (PV) energy based sources to the grid poses a
number of problems. Nowadays, transformerless converters
are preferred for higher efficiency, low size low device
stresses, and low current ripple. The output voltage of PV
arrays is relatively low, requiring a high step-up converter to
obtain the DC voltage input of the inverter. The PV power
generation block diagram is composed of PV, Boost DC-DC
Converter, energy storage element, and bidirectional DC-DC
converter, as depicted in Fig. 1
Fig.1. PV power generation block diagram.
Many step-up switch structures have been presented to
provide a high efficiency without extremely high duty ratio
and for reducing the output current ripple [8]-[10].the basic
step-up inductors block is given in fig.2. Accordingly, for this
block during the switch –on period and are charged in
parallel as shown in fig.2a and during off period and are
charged in series as shown in fig.2a.
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Asian Transactions on Engineering (ATE ISSN: 2221 - 4267) Volume 02 Issue 04
( ) [ ( )][ ] ( ) (2)
( ) [ ( ) ]
(3)
Where :
Fig.2. Inductors block.( a) inductors block when switch turn –on (b) inductors
block when switch turn –off
√
II. OPERATIONAL ANALYSIS OF PROPOSED BOOST CONVERTER
The configuration topology of the proposed converter with
soft switching scheme is shown in Fig.3, the switch , , ,
, , , and are the main boost converter
components, while R represents the resistive load on the
converter. Inductor , , , and form the auxiliary
circuit for accomplishing the soft switching of . Inductors
and are much smaller than , and is much smaller
than .
When
stops conducting and this stage comes to an end.
2) Stage 2: The initial conditions on , and are,
( ) , ( ) respectively, attained at the
end of. Stage 1.The expressions are Eq. 4-6:
( ) ( )[ ]
( )
( ) (4)
( )
( )
[ ]
( ) (5)
( )
( )
[ ]
( ) (6)
Where:
Fig.3. The proposed high voltage gain dc-dc boost converter
√( )
The operating stages of the proposed topology can be divided
into seven stages:
1) Stage 1: This stage begins with the turn on of , at zero
current at .The expressions are Eq. 1-3:
( )
Where and with the same level of inductance are charged
parallel.
This stage comes to an end when reaches zero at .
( ) (1)
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Asian Transactions on Engineering (ATE ISSN: 2221 - 4267) Volume 02 Issue 04
3) Stage 3: The initial conditions on , and for
this stage. ( ), ( )are zero. The expression for
( ) is:
7) Stage 7: In this stage , are zero. This stage comes to
an end at when is turned on at zero current. This is the
normal stage of the boost converter. The expressions are:
( ) [ ] (15)
( )
( )
( ) (7)
This stage comes to an end at when reaches zero at .
4) Stage 4: In this stage current buildup in and and ( )
are governed by the Eq. as follows.
( )
( )
(8)
( )
( ) ( )
[( )
( ) ] ( )
Where :
( )
( )
(9)
√
( )
Where:
( ) ( ) ( )
Where is the equivalent inductance for parallel equivalent
inductors and .
This stage comes to an end when is turned off at zero
voltage at .
5) Stage 5: This stage begins with the turn off of at zero
voltage at .The expressions are:
( )
( ) ( ) (10)
[ ( )] (11)
( )
[ ( )] (12)
( )
6) Stage 6:In this stage reduces to zero. This stage
comes to an end at when becomes
zero. The expression for and for these stage is.
( )
( ) (13)
Where is the equivalent inductance for equal series
inductors and .
III. EXPERIMENTAL RESULTS
Prototype circuit is built in the laboratory To verify the
theoretical analyses of proposed converter for use in PV
application, the circuit specifications and components Are
selected as =15V, = 70 to 130V, = 330ρF and
=100µF. = =130µH, =5.4ρH, =3.3pH.Moreove
r, IGBT HGTG20N60B is selected for switch s1and ultra fast
diode 60EPU04P is used for , , and .Moreover, two
diodes 6A05 selected for and .
Under the condition =15V and the switch frequency
=30KHZ, some experimental results at duty cycle 80%are
shown in Fig.4. and it shows that the mean power input is
approximately equal 35W moreover the output voltage is
equal 130V .
Fig.5. shows the experimental efficiency of the proposed
converter according the output voltage range. The proposed
converter can achieve high step-up voltage gain as shown in
Fig. 6.
( ) [ ( ) ][ ](
( )
) (14)
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Asian Transactions on Engineering (ATE ISSN: 2221 - 4267) Volume 02 Issue 04
IV. CONCLUSION
This paper has presented a lossless dc-dc boost converter
with high step-up voltage gain for the low output photovoltaic
voltage. The major advantages for this topology are high
boosting ratio with low voltage stress on the switch, low size
and cost .The parallel/series inductors cell with snubber cell
based on the active switch of proposed topology investigated
and a circuit prototype with an output of 130V with efficiency
(90-94)% is designed .The experimental results have proven
good performances and verify the feasibility of the proposed
circuit, and the voltage gain can be achieved for low output
photovoltaic problem . More future work will highlight to
decrease the voltage stress on the drive switch with a
promising cost, size, and efficiency optimization.
Fig.4. Experimental result for proposed topology
ACKNOWLEDGMENT
I would like to express my sincere gratitude to Mr. Said
Abdalla and Ms Sabriah Halhoul and Arca family for
invaluable help and support all over this work.
REFERENCES
Fig.5. The experimental efficiency of the proposed converter
according the output voltage range
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photovoltaic power system”, IEEE international conference on
sustainable energy technologies ICSET 2008, Pp 607-610, Singapore,
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[2] M. C. Cavalcanti, G. M. S. Azevedo, B. A. Amaral, K. C. de Oliveira, F.
A. S. Neves, and Z. D. Lins, “Efficiency evaluation in grid connected
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[4] F. Al Hassan. “Transformerless Battery Charger by Using Constant
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[5] B.-T. Irving, and M.-M. Jovanovic, “Analysis, design, and performance
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[6] J.-H. Kim, Y.-C. Jung, S.-W. Lee, T.-W. Lee, and C.-Y. Won, “Power loss
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[8] L. S. Yang, T. J. Liang, and J. F. Chen,―Transformerless DC-DC
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Fig.6. The proposed converter voltage gain verses duty cycle
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Asian Transactions on Engineering (ATE ISSN: 2221 - 4267) Volume 02 Issue 04
Falah AL Hassan was born in Jordan in 1978.He
received the B.S of Science in the section of Electric
Engineering from Princess Sumaya University for
Technology / Royal Scientific Association in Jordan
in 2001. And high honor M.S. degrees of Science in
Electrical and Electronic Engineering from Eastern
Mediterranean University in Cyprus in 2010. He is
currently working toward the Ph.D. degree. He is a
member of Jordan and Cyprus Section IEEE and
Member of Jordanian Engineers Syndicate.
He has 9years experience works: Electric
Engineering Officer at the Jordanian Armed Forces / Royal Maintenance
Armament, Jordan Telecommunications Company (JTC), Jordan Ministry of
Energy, power system lab in Electrical and Electronic EMU. he is author of
five international papers His main research interests include dc-dc converter
ac-dc converter ,power maintenance ,design high efficiency converters for PV
system, and Ultrasonic Technology.
Vladimir Lanin received the PhD in Electronic
Engineering at Sanct Petersburg Technical Institute,
Russia in 1982. He is Dr. Sci. Tech., professor at the
Electronic Engineering and Technology Department
of the State University of Informatics and
Radioelectronics, Minsk, Belarus.
He is a member of Belarus Section IEEE. He has
more than 25 years of experience in Ultrasonic
Technology and Technology of Electronics
Production. Basic research area: technology of
electronic devices. He is the author of books:
“Ultrasonic Soldering in Radio and Device Production” 1985, “Ultrasonic
Processes in Electronics Production” in 2 volume 2002, and 2003, “
Formation of Сurrent–carring Contact Connections in Electronics Devises”
2007, publishing in Belarus.
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