Page 1 of 9
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 1769
Analysis of High Power Dc-Dc Converter Based On
Interleaved Circuit for Fuel Cell
REGURAJA .P
PG Student
PRIST Deemed to be University, Thanjavur
Abstract—Among all types of green energy, fuel cells are
widely known for its applications in standalone or grid connected
systems because of its efficiency and reliability. Unfortunately,
the fuel cell has some weak points, which are low output voltage
and high input current ripple. This paper presents the multi
device interleaved boost converter (MDIBC) to overcome the
weakness that mention above. MDIBC produced high efficiency
compared to other DC-DC converter which have reduced the
input ripple current and size of passive component. The MDIBC
is compared with an interleaved boost converter (IBC) to analyse
its efficiency. The MDIBC and IBC converters structures are
simulated using MATLAB/Simulink. The simulations have
shown that MDIBC is more efficient and less input current ripple
produced compared to the IBC.
Index Terms—DC/DC Converter; Fuel Cell.
I. INTRODUCTION
Problems with energy supplies and use become the trending
because of environmental concerns such as air pollution, acid
precipitation and radioactive substance submissions. To avoid
these issues from getting bigger, some potential solutions have
been developed, including the energy conservation through
improved energy efficiency, a reduction in fossil fuel use and
increase in environmentally friendly energy supplies. Among
the renewable energy development nowadays, fuel cell (FC) is
considered as one of the reliable alternative energy sources for
the future. The fuel cell is chosen because of their cleanliness,
high efficiency and high reliability [1]. There are various types
of fuel cells available for many applications such as alkaline
fuel cell (AFC), phosphoric acid fuel cell (PAFC), molten- carbonate fuel cell (MCFC), proton exchange membrane
Melaka fuel cell (PEMFC), and solid oxide fuel cell (SOFC).
PEMFC has been chosen to be the most suitable since it has
high power density with lower operating temperature [2, 3].
Unfortunately, this type of fuel cell has several limitations.
It has a wide range of low DC output voltage, slow dynamic
performances during load variations and low efficiency [4]. In
order to deal with the variant low voltage fuel cell, a stable
DC-DC boost converter is needed. It generated the desired
level of voltage without increasing the fuel cell stack, thus
maintain the cost of constructions [5]. Abutbul et al integrated a
switched-capacitor circuit inside boost converter to achieve a
desired voltage ratio [6]. The slow response in fuel cell system
leads to the additional secondary energy storage to support the
system during transient power or overload condition [7]. A
Page 2 of 9
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 1770
discussion on high power interleaved boost converter for
fuel cell were presented in [8], which can reduce the high
frequency switching ripple. Ripple and harmonic content
are those phenomena that could affect the lifespan of fuel
cell. Thus, to ensure energy efficient operation of the fuel
cell stack, the output current ripple should be reduced [9].
This research will cover the low voltage and ripple current
in fuel cell system. A DC-DC converter that interfaced
between fuel cell system and load had been chosen to solve
this problem.
Figure 1 shows the interleaved boost converter (IBC),
while Figure 2 shows the multi device interleaved boost
converter (MDIBC). Even though MDIBC has more
IGBTs compared to the IBC, the value of passive
component is reduced and cause the reduction in converter
weight as the high power passive component is weighted
more than the IGBTs. Due to more advantages of MDIBC
compare to IBC, the detail analysis of MDIBC is
investigated in this paper. Table I shows the comparison
between the two converter’s advantages.
Table 1
Converters comparisons
[10]
Converter Advantages
IBC Simple configurations
Reduce ripple in current/voltage signal
MDIBC
Higher conversion efficiency
Reduced the total convertersize/weight
Reduced more ripple to provide more efficient
power conversion
In this paper, a MDIBC has been studied and analysed to
reduce the size and weight of the passive components.
Meanwhile, the input current ripple and output voltage can
be minimized efficiently. This converter will be compared
with an IBC to study the efficiency and dynamic
performances. Simulation results are provided.
II. OPERATING OF MDIBC
MDIBC converter was chosen because of its power
conversion efficiency is higher compared to the other
interleaved converter. In this paper, the structure of
MDIBC is shown in Figure 2 [10]. This converter consists
of a two-phase interleaved boost converter with two
switches and two diodes connected in parallel. To reduce
the size of the inductor, capacitor and input/output EMI
filter, the frequency of the inductor, capacitor in parallel.
To reduce the size of the
Page 3 of 9
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 1771
inductor, capacitor and input/output EMI filter, the frequency
of the inductor current ripple and the output voltage ripple
should be increased. To achieve the control strategy, the
phase-shift interleaved will be applied. This control strategy
provides the doubled ripple frequency in inductor current at a
same switching frequency. This could contribute to higher
system bandwidth. The bandwidth helps in fast dynamic
response in the converter and passive component size
reduction. Figure 1 shows the conventional interleaved boost
converter (IBC) that will be compared to the MDIBC for
performance analysis.
Ro
Figure 1: Interleaved boost converter, IBC
Ro
Figure 2: Multi device interleaved boost converter, MDIBC
The converter is simulated using MATLAB/Simulink in
order to analyse the performances. These simulations are
carried out with input voltage of 24V; 10 kHz switching
frequency, Fs. The value m is the number of parallel switches
per channel, and n is the number of channels or phases.
The design parameters are shown as below:
i. Boost ratio, the voltage gain of the converter is a
function of the duty cycle and defined as:
ii. Input current can be calculated as below:
iii. Inductor current ripple peak-peak amplitude is given
by:
iv. Selection of inductor and capacitor:
v. Choosing the number of phases:
The ripple content reduce with the increasing number of
phases. But, there is the limitation of the number of phase
because it might increase the cost of components.
L
RL Rc
L
RL C
S1 S2
FUEL
CELL
STACK
L
RL Rc
L
RL C
S1 S2 S3 S4
FUEL
CELL
STACK
(1)
(2)
(3)
(4)
(5)
