BABA INSTITUTE OF TECHNOLOGY AND SCIENCES
VISAKAHPATNAM
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
FULL-BRIDGE CONVERTER BASED HIGH-GAIN MODULAR DC-DC
CONVERTER WITH MEDIUM-VOLTAGE DC GRIDS FOR EV AND PHEV
SUBMITTED BY
L SAI KUMAR
19NR1D5405
POWER ELECTRONICS AND ELECTRICAL DRIVES
Under the guidance of
K Venkateswara Rao M.Tech.,(Ph.D
Asst.Professor
Department of EEE
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CONTENTS
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Objective
Introduction
Circuit Diagram
Design of Converter
Features
Operation of Converter
Simulink Models
Results
Comparison
Plan of Action
Conclusion
Future scope
References
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OBJECTIVE
The output voltage level of renewable energy source is
usually low so with the help of DC-DC converter we can boost
the voltage to sufficient voltage level.
The High Gain DC-DC Full-Bridge converter with
integrated passive snubber network is helpful in obtaining high
voltage with low ripple content that will be useful in charging
electric and plugged hybrid electric vehicles.
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INTRODUCTION
• DC-DC converters with boost up capability are widely used in
a large number of power conversion applications where output
from fraction to hundred of volts.
• The applications that require high voltage are hybrid electric
vehicle and also in the telecommunication. But this hundred of
volts cannot be obtained from the renewable energy systems /
sources. So , the output of the alternative sources should be
stepped up by using the high gain DC-DC converters.
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CIRCUIT DIAGRAM
Fig 1. High gain DC-DC converter with stacked capacitors
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DESIGN OF CONVERTER
• The converter, shown in Figure1, consists of a four switch fullbridge, S1, S2, S3 and S4, an input inductor L, a power
transformer T3, secondary diodes D1 and D2 and an output
capacitor Co2.These components constitute the main part of
the converter circuit.
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The converter also has a snubber circuit that consists of
capacitors C1 and C2, transformers T1 and T2, and diode Dz.
continues…
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CONTINUES…
• Diodes D3 and D4 are the secondary diodes for transformers
T1 and T2 respectively and capacitors Co1 and Co3 are the
secondary output capacitors for the two auxiliary snubber
circuit transformers.
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FEATURES
• Snubber network is used in the converter,so it is helpful to
supress the voltage spikes which may occurs during the
switching operation.
• Passive snubbers are used in the converter which are cheaper
and more reliable than passive snubbers.
• This converter is helpful in obtaining high voltage gain for the
low input voltage gains.
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OPERATION OF CONVERTER
The converter shown in the Figure 1 is essentially a boost
converter, but with transformer isolation and a DC bus
snubber.When the input inductor operating with continuos
current,the main power circuit has two basic modes like a
boost converter.
1. Short Circuit Mode
2. Energy Transfer Mode
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Mode 1 (t0 < t < t1)
Fig 2. Mode 1 (t0<t<t1)
Fig 3. Gating Sequence
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Mode 2 (t1 < t < t2)
Fig 4. Mode 1 (t0<t<t1)
Fig 5. Gating Sequence
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Mode 3 (t2 < t < t3)
Fig 6. Mode 1 (t0<t<t1)
Fig 7. Gating Sequence
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Mode 4 (t3 < t < t4)
Fig 8. Mode 1 (t0<t<t1)
Fig 9. Gating Sequence
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SIMULINK MODELS
Fig 10.Simulink model for high DC-DC converter with stacked capacitor for
vehicle charging system
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Fig 11.Output voltage of high gain DC-DC converter with stacked output capacitor
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SIMULINK MODELS
Fig 12. Simulink model for high gain DC-DC converter with single output capacitor
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Fig 13.Output voltage of high gain DC-DC converter with single output capacitor
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COMPARISON
SI .No
1.
CONVERTER
Transformerless
SWITCH
NUMBER OF
FREQUENCY
INPUT
OUTPUT
USED
SWITCHES
(HZ)
VOLTAGE(V)
VOLTAGE(V)
DC-DC MOSFET
2
100000
48
282.5
2
25000
48
227.3
1
25000
48
113.9
DC-DC MOSFET
2
50000
48
90
An improved ZVT PWM boost MOSFET
2
100000
48
302.6
1
10000
48
94.21
4
50000
48
400
converters with high step-up
voltage gain
2.
High frequency PWM boost MOSFET
chopper-fed DC-DC converters
with coupled-inductors
3.
Coupled inductor boost converter MOSFET
with
enhanced
capacitor
for
ESR
DC
filter
microgrid
applications
4.
A
new
ZVT-PWM
converter
5.
converter
6.
Family of Soft switching PWM MOSFET
converters using coupled passive
snubber
7.
High gain DC-DC converter with MOSFET
integrated
network
passive
snubber
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CONCLUSION
Based on the respective merits of the snubber network and
the full-bridge DC-DC converter, a new high gain DC-DC
full-bridge converter with integrated passive snubber network
was proposed. The operating principle analysis and the
comparison with other existed high gain DC-DC converters
have been presented in detail. Finally, simulation results are
given to validate the effectiveness of the proposed converter.
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FUTURE SCOPE
In comparison with other existed high gain DC-DC
converters, the proposed converter provides higher output
voltage gain, lower current stress across the switches. Thus the
efficiency and reliability of the proposed converter can be
improved, which implies that it would be suitable for high
step-up voltage conversion applications, such as TV-CRTs, Xray systems, hybrid-electric vehicles, high intensity discharge
lamps for automobile headlamps, as well as grid connection of
renewable energy sources.
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