Download a cockcroft–walton voltage multiplier fed by a three-phase-to

A COCKCROFT–WALTON VOLTAGE MULTIPLIER FED BY A THREEPHASE-TO-SINGLE-PHASE MATRIX CONVERTER WITH PFC
Mr.P. TENDULKAR[1] Mr. S. JOTHI BASKARAN[2] Mr. M. SUBRAMANI [3]
Mrs. J.SANTHI[4]
Mr.G. SUGUMARAN[5]
ABSTRACT
This paper proposes a single-stage
three-phase-to single-phase current-fed high
step-up ac–dc matrix converter. The
proposed converter inserts a Boost type
matrix converter, which is formed by three
boost inductors and six bidirectional
switches, between a three-phase ac source
and a Cockcroft–Walton voltage multiplier
(CWVM).By using this topology associated
with power factor correction technique,
proposed converter not only achieves almost
unity power factor and sinusoidal input
currents with low distortion but also obtains
high voltage gain at the output end.
Moreover, the matrix converter generates an
adjustable-frequency
and
adjustableamplitude current, which injects into the
CWVM to regulate the dc output voltage
and smooth its ripple. With this flexible
injection current, the performance of the
proposed converter is superior to the
conventional CWVM, which is usually
energized by a single-phase ac source. The
operation principle, control strategy, and
design considerations of the proposed
converter are detailed in this paper. Finally,
simulation
and experimental results
demonstrate the claims and validity of the
proposed converter.
INTRODUCTION
Conventionally, most of the dc
sources were from ac–dc converters, except
some dc-powered systems Depending on the
application requirements, many circuit
topologies have been well developed for
different voltage levels, different power
rating, and different ac sources. When high
dc voltage was required, high voltage gain
was an important issue to determine the
suitable topologies to achieve the high
voltage output. Boost-type non isolated dcdc converters, which not only provide high
voltage gain but also promise high
efficiency and compactness, were popular
for high-voltage applications.When these
kinds of converters were supplied by ac
source, an ac–dc stage had to deploy at the
front end to form a two-stage topology.
Thus, the advantages of these high step-up
converters will be deteriorated. When
necessary, these two-stage topologies could
employ
a
high-frequency
step-up
transformer to obtain more voltage gain.
However, this led to increasing cost and
bulk, and decreasing efficiency further.
When high power was required, three-phase
ac sources were superior to single-phase ac
sources in providing energy to the
aforementioned ac–dc converters.In threephase single-stage ac–dc power converters,
including buck type, boost type, buck–boost
type, multilevel type, and multi pulse type,
were summarized. In this review literature,
most of these ac–dc converters used power
factor correction(PFC) techniques to
improve the ac line conditions in terms of
power factor (PF) and total harmonic
distortion of input currents (THDi) and
offered adjustable or regulated output for the
variable loads.
EXISTING SYSTEM
Here, the mathematical model of the
proposed converter will be derived first, and
then, the operation principle will be
described as well. Shows the proposed
converter, which is supplied by a threephase ac source, and the phase voltages are
denoted by van, vbn, and vcn, respectively.
The three right terminals of the upper-part
switches connect to the upper terminal D of
the CWVM, whereas the three right
terminals of the bottom-part switches
connect to the bottom terminal E of the
CWVM. For simplicity, the derivation of
the mathematical model is divided into two
parts, namely, the ac-side part and the
CWVM, which are separated by terminals D
and E.
A three-phase to single-phase matrix
converter, which is composed of three boost
inductors (La, Lb, and Lc) and six
bidirectional switches(Sa1, Sb1,Sc1, Sa2,
Sb2, and Sc2), is inserted between the ac
source and a conventional N/2-stage CWVM
circuit, where Nis an even integer. Two antiseries insulated-gate bipolar transistors form
one bidirectional switch, as shown in the
bottom left part in.The six bidirectional
switches are divided into two parts, namely,
the upper part (Sa1, Sb1, and Sc1) and the
bottom part (Sa2, Sb2, and Sc2). According
to the first subscripts of the switches, the left
terminals of the switches connect to the
relative ac sources through three boost
inductors
PROPOSED SYSTEM
Here, the mathematical model of the
proposed converter For simplicity, the
derivation of the mathematical model is
divided into two parts, namely, the ac-side
part and the CWVM, which are separated by
terminals D and E.Here the model worked at
the number of stages by using about the
matrix converter. By this converter using as
will provide them voltage improved and
power factor also improved them.In this
technique are used the four stages of the
Cockcroft Walton voltage multiplier circuit
and in the existing system are used to the
Six stages are used them and six bidirectional switches are used them but
proposed system are overcome the system
here used as four stages and three bidirectional switches are used to improve the
voltage level and power factor.Here that
using about the multiplier circuit CockcroftWalton (CW) is a voltage multiplier that
converts AC or pulsing DC electrical power
from a low voltage level to a higher DC
voltage level.
SIMULATION DESIGN
Fig- 1 Block Diagram of Hardware
This gives information to the opto
coupler where the phase from which the
power has to be taken is sensed and
corresponding switching operation is
performed. Thus the speed of operation of
sensing the phase depends directly on the
control circuit and not on opto coupler. The
opto coupler just performs the work as
according to the instructions given by the
control circuit.The control logic circuit not
only gives signal to opto coupler but it has
to give signal to relay driver section also
simultaneously. This is the reason the
control logic circuit is very important.The
relay driver gets signal from the control
logic circuit and according to the signal it
will activate the corresponding relay to
operate.
TABLE 1: TRUTH TABLE OF PHASE
SELECTOR
A simulation design modulation
technique is shown 6.6 is implemented in
MATLAB SIMULINK with the help of the
Cockcroft Walton voltage multiplier with
single phase to three phase converter fed by
a PFC.If the any one phase cut the supply to
continue supply to the to all the three phase
supplied them.By the concept is the
occurred matrix converter to converted the
DC supply to the repeated the process of the
inverted the supply by using the IGBT used
them.IGBT as that worked with the
triggering pulse applied them working
process worked the phase selecting mode
and the working about the three phase
supply continuously worked them.
CONCLUSION
In this paper, a three-phase-tosingle-phase current-fed high step-up ac–dc
matrix converter based on CWVM without a
line and high-frequency step-up transformer
has been presented to obtain high voltage
gain. By using current hysteresis control to
implement PFC, the proposed converter
offers almost unity PF with low THDiat the
ac mains; meanwhile, the matrix converter
provided an adjustable-frequency and
adjustable amplitude current to feed the
CWVM to regulate the dc output and
smooth ripple voltage. The programmable
alternation frequency can be used to
improve the ripple effect according to the
application requirement. However, too much
higher alternation frequency deteriorates the
performance of the system; thus, the highest
alternation frequency should be limited.
The circuit operation, control strategy, and
design considerations of the proposed
converter were detailed in this paper. Two
simulation cases were conducted to evaluate
the performance of the proposed converter.
A500-W prototype. Both simulation and
experimental work were conducted, and
their results demonstrated the validity and
the good performance of the proposed
converter. Compared with conventional
CWVM, the proposed converter sourced by
a three-phase source is quite suitable for
high-voltage and high-power applications.
REFERENCES
[1] Y. Xue, L. Chang, S. B. Kjaer, Jr., J.
Bordonau, and T. Shimzu, “Topologiesof
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power generators: Anoverview,” IEEE
Trans. Power Electron., vol. 19, no. 5, pp.
1305–1314,Sep. 2004.
[2] L. S. Yang, T. J. Liang, and J. F. Chen,
“Transformerless dc–dc converterswith high
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Electron., vol. 56, no. 8,pp. 3144–3152,
Aug. 2009.
[3] W. Li and X. He, “Review of nonisolated high-step-up dc/dc convertersin
photovoltaic grid-connected applications,”
IEEE Trans. Ind. Electron., vol. 58, no. 4,
pp. 1239–1250, Apr. 2011.
[4] D. Zhou, A. Pietkiewicz, and S. Cuk, “A
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177–183,Jan. 1999.
[5] J. Tanaka and I. Yuzurihara, “The high
frequency drive of a new multistagerectifier
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Spec. Conf., Apr.
1988, pp. 1031–1037.
[6] J. F. Chen, R. Y. Chen, and T. J. Liang,
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P.TENDULKAR
G. SUGUMARAN
Department of Electrical
and Electronics
Engineering of Podhigai
College Of Engineering
And Technology
Tirupattur635 601
Assistant Professor
,Department Of EEE
Podhigai College Of
Engineering And
Technology Tirupattur
S. JOTHI
BASKARAN
Department of Electrical
and Electronics
Engineering of Podhigai
College Of Engineering
And Technology
Tirupattur-635 601
M. SUBRAMANI
Department of Electrical
And Electronics
Engineering of Podhigai
College Of Engineering
And Technology
Tirupattur-635 601
J.SANTHI
Assistant Professor
,Department Of EEE
Podhigai College Of
Engineering And
Technology Tirupattur
635 601
635 601