Renewable energy sources offer a clean production of
electrical power from sunlight, wind, biomass, tidal waves
etc.
Renewable energy generation has grown greatly due
to the concerns of climate change and the increase in oil
prices. The growth in renewable energy has been very
consistent in the last two decades. Not only the increasing
concerns regarding climate change and the increase of oil
prices but also the great support by renewable energy
legislation and incentives with a close to 150 billion US
Dollars in 2007 have brought this alternative source of
electrical power generation [15].
Photovoltaic (PV) systems are one of the most popular
renewable energy sources. It is an interesting energy source
as it is not only renewable but also inexhaustible and non
polluting unlike the conventional fossil fuels such as coal,
oil and gas. These unique features have made power
generation through Photovoltaic sources one of the most
popular renewable energy sources in the last decade [3].
Photovoltaic convert sunlight into electrical energy using
photoelectric effect. Sun's radiation is converted directly
into usable electricity by photovoltaic systems. Photovoltaic
(PV) systems are made of photovoltaic modules which are
semiconductor devices that convert the solar radiation
directly into electrical energy [3]. The power generated
using solar energy is stored in batteries during the sunshine
hours and is consumed during night.
A lot of research has been done to improve the efficiency of
the PV modules. A number of methods to track the
maximum power point of a PV module have been proposed
to overcome the efficiency limitation [10][17]. The use of
the newest power control mechanisms called the Maximum
Power Point Tracking (MPPT) algorithms leads to increase
the efficiency of solar module operation and is effective in
the field of utilization of renewable sources of energy.
MPPT algorithm controls the power converters to
continuously detect the instantaneous maximum power
working point of the PV array [2][4][8].
Perturb and observe (P&O) methods are widely applied as
an MPPT controller due to their simplicity and easy
implementation.
The P&O methods involves a perturbation in the operating
voltage of the PV array, Incremental conductance (IC)
method, which is based on the fact that the slope of the PV
array power versus voltage curve is zero at the MPP has
been proposed to improve the tracking accuracy and
dynamic performance under rapidly varying conditions
[6][7], and Fuzzy logic MPPT method which doesn't need
the knowledge about model of the system, Inputs of the
fuzzy logic controller are the error of the system and the
change of error[5][9][13] .This control is better suited for
non-linear systems. An improved MPPT algorithm for PV
sources was proposed to reduce the involved tracking time
where a dc-dc boost converter was used to track the MPP
and was brought out that tracking performance depends
PV System with Battery Storage Using Bidirectional DC-DC Converter
ACHWAK ALAZRAG, L. SBITA
Process laboratory, Energetics, Environment and electrical systems, LR18ES34, National Engineering School
of Gabes, University of Gabes, TUNISIA
Abstract: With the increase in demand for generating power using renewable energy sources, energy storage
and interfacing the energy storage device with the load has become a major challenge. Energy storage using
batteries is most suitable for renewable energy sources such as solar, wind etc. A bi-directional DC-DC
converter provides the required bidirectional power flow for battery charging and discharging mode. The duty
cycle of the converter controls charging and discharging based on the state of charge of the battery and direction
of the current. In this paper, a nonisolated bi-directional DC-DC converter is designed and simulated for energy
storage in the battery and interfacing it with the DC grid. The power extracted from the solar panel during the
daytime is used to charge the batteries through the DC-DC converter operating in buck mode and when solar
power is unavailable, the battery discharges to supply power to DC load through the converter operating in
boost mode. Solar arrays connected through a DC bus to a load. Due to the instantaneous changes of solar
irradiance and temperature, maximum power point tracking (MPPT) is integrated in the inverter control. The
technique of maximum power point tracking (MPPT) is used in photovoltaic systems to extract the maximum
power. The most popular MPPT techniques are reviewed and studied, such as: Perturb and Observe, Increment
of Conductance and control based on fuzzy logic (LF). The simulation is done in matlab/simulink and results
are presented.
Keywords: — photovoltaic system, Boost converter, bidirectional DC-DC converters, MPPT.
Received: September 19, 2022. Revised: February 16, 2023. Accepted: March 15, 2023. Published: May 4, 2023.
1. Introduction
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
11
Volume 5, 2023
upon the tracking algorithm. The overall performances of
the PV system depends on the type of the DC-DC converter
used and the algorithm used for tracking the MPPT both of
this parameter plays an important role in increasing the
performance of the PV array [1][11].The main objective of
this work is to model and analyze a photovoltaic system
incorporating battery energy storage systems based on
bidirectional DC-DC converters comparative study between
the three performed algorithms which is incremental
conductance algorithm , perturbs and observe algorithm and
fuzzy logic. The boost converter used to compare in this
study.
Photovoltaic devices are nonlinear devices. Their
parameters are sunlight and temperature dependent. Sunlight
is converted into electricity by photovoltaic cells.
Photovoltaic arrays consist of parallel and series of PV
modules. In order to form the panels or modules cells are
grouped together. Not only a DC load can be fed by the
voltage and current produced at the terminals of a PV but
they can also be connected to an inverter to produce
alternating current. Photovoltaic cell models have been used
for the description of photovoltaic cell behaviors for
researchers and professionals for a long time. The Single
diode circuit model is among the most common models
which are used to predict energy production in PV cells [3].
The equation relation of the output current and PV module
p ph d sh
I I I I
(1)
And :
(2)
Photo-current of the module :
.[exp( ) 1]
p s p p s p
p ph s
T sh
V R I V R I
I I I VR

(3)
ph
I
:photo-current,
cc
I
: Short circuit current of the cell under the standard
conditions reference (
ref
E
and
ref
T
),
E
: Sunshine received by the cell (
2
/Wm
),
ref
E
: Reference sunshine,
icc
K
: Current short-circuit-temperature coefficient (A/°C),
..
Bj
T
n K T
Vq
: Thermodynamic potential
s
I
: Inverse current saturation of the diode,
q : Charge of an electronn,
B
K
: Constant of Boltezmann,
j
T
: temperature of the junction(°C),
n: Ideal factor of the solar cell.
pv
I
: Output current of the photovoltaic cell,
pv
V
: Output voltage of the photovoltaic cell.
Incorporation of series resistance and shunt resistances
provide accurate modeling opportunity of the PV cell as
s
R
corresponds to the internal losses due to current flow and
p
R
corresponds to the leakage current to the ground.
Incorporation of series module (cells)
s
n
increases the
output voltage of photovoltaic array and incorporation of the
parallel module
p
n
increases the output current of the
photovoltaic array. Manufacturers of PV modules provide
reference values for specified operating condition such as
STC (Standard Test Conditions) for which the irradiance is
1000
2
/Wm
and the cell temperature is
25 C
. Practical
operating conditions are mostly different from the desired
standard conditions, mismatch effects can also affect the
real values of these mean parameters. The Simulink
implementation of this photovoltaic model is shown in
figure2. The Simulation was carried out for different levels
of irradiances and also for different temperature levels.
Irradiation level was varied from 0
2
/Wm
to
1000
2
/Wm
and the resultant P-V and I-V curves can be
seen in Figure 3 and 4 .
Figure 1 : Integration of battery energie storage system
to solar PV panel
Figure 2 : Equivalent model of real cell
Figure 3 : PV generator
2. PV array
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
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E-ISSN: 2769-2507
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Volume 5, 2023
Ns
-Voltage are added
-Current remains constant
Np
-Current are added
-Voltageremains constant
The PV generator can be characterized by current / voltage
curve, often called "characteristic I = f (V) and P = (V)".
The following figure ensures the extraction of the optimum
power from the photovoltaic generator.
Or the equations relation of the PV generator;
pvg phg dg shg
I I I I
(7)
.[exp( ) 1]
dg
dg sg
Tg
V
II V

(8)
With the diode generator voltage is :
dg pvg sg pvg
V V R I
(9)
.
Tg s T
V n V
(10)
Or
.
phg p ph
V n V
(11)
The overall current delivered by the PV generator is :
.
.[exp( ) 1] . p s p
d
pvg p ph s
T sh
V R I
V
I n I I VR
(12)
It is clear that the relationship between the output current
and the voltage of the generator nonlinear because of the
exponential. the result of simulating the generator current as
a function of its voltage is a single representation where the
output current is a constant during a well defined interval of
the generator until it reaches a point where it begins to
decrease. The figure shows Variation of the current and the
power of the generator according to the voltage under
different irradiations and at temperature equal to 25 ° C.
The Simulation results obtained from the Figures 3 and 4
exhibit that the voltage variation with the change of
irradiation is very little whereas with the increase in
temperature the voltage decreases .Typically the voltage will
decrease .It can also be seen that each curve has an
operating point for a certain operating voltage at which the
module produces the maximum power. This point is known
as the Maximum Power Point(MPP). The aim is to operate
the photovoltaic system at this maximum point to extract
maximum power from the module. It can also be observed
that at different levels of solar irradiation the open circuit
voltages are almost the same and at different levels of
temperatures the short circuit currents are almost the same.
This in turn illustrates that at different levels of solar
irradiation, the voltage at which maximum power point is
located is almost the same. But at different levels of
temperatures, the maximum power point is located at
various operating voltages which are far from each other.
This maximum power point varies at every instance and to
have an efficient system it is necessary to track this
maximum point at every instance of operation.
The maximum power (MP) is obtained when the solar panel
is being operated at the voltage where the global maximum
of the P-V characteristic lies. It shows that for one specific
operating point, the maximum power output can be obtained
from the solar panel. This point in the P-V characteristic
curve is called the Maximum Power Point (MPP). This
point lies always on the knee of the I-V curve of the solar
panel. In summary it can be concluded that on the I-V curve
of the solar panel there is a point called MPP(Maximum
power point) which always occurs on the knee of the curve
where the generated PV power is maximized. This MPP
changes with the change of the irradiation and temperature
[4]. The irradiation and temperature are dynamic in nature,
therefore the MPP tracking algorithm has to be working
practically in real time by updating the duty cycle constantly
and thereby keeping the speed and accuracy of tracking [8].
Figure 4 : Characteristic I = f (V) and P = (V).
Figure 5 : Variation of the current and the power of the
generator according to the voltage under different irradiations
and at temperature equal to 25 ° C
3. Maximum Power Point Tracking
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
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Volume 5, 2023
The algorithm is executed by the MPPT controller to find
the MPP. The measured output voltage and current of the
solar panel are inputs of the controller. The algorithm
performs its calculations depending on these inputs. The
controller produces an output which is the adjusted duty
cycle of the PWM. It drives the DC-DC converter‘s
switching device. For every different operating point the
controller produces a different duty cycle.
To obtain the maximum power from the solar panels, an
efficient tracker algorithm is required for the MPPT. The
tracker algorithm‘s task is to track the maximum power
point of the solar panel as accurately as possible. The
algorithm also has to be fast and reliable as well.There are
several principles of operation of MPPT
algorithms more or less successful based on the properties
of the PV array.
And Table 1 summarizes the main specifications of the
various and famous MPPT algorithms previously presented.
Was evaluated and compared these algorithms in terms of
complexity, precision, speed and technical knowledge of PV
panel settings.
TABLE1 : Technical compare of MPPT
MPPT
P&O
InC
LF
Sensors use
1voltage
1current
1voltage
1current
1current
Identification pv
panel
parameters
Not
necessary
Not
necessary
Yes
necessary
Complexity
low
medium
high
Number of
iterations
45
48
27
Speed of
convergence
medium
medium
very fast
Precision
95%
98%
99%
In this work, we interested t study the three famous
algorithm :
The principle of this control algorithm is to generate
disturbances by reducing or increasing the duty cycle and
observe the effect on the power output of the PV generator
[6][7].
The P&O method operates periodically incrementing
or decrementing the output terminal voltage of the PV
and comparing the power obtained in the current cycle
with the power of the previous cycle. If the voltage varies
and the power increases, the control system changes the
operating point in that direction, otherwise change the
operating point in the opposite direction. Once the
direction for the change of current is known, the current
is varied at a constant rate. This rate is a parameter that
should be adjusted to allow the balance between faster
response with less fluctuation in steady state. The
flowchart of this algorithm is presented in Figure 7.
A modified version is obtained when the steps are changed
according to the distance of the MPP, resulting in higher
efficiency. A frequent trouble in P&O methods is that the
output terminal voltage of the PV is perturbed every
MPPT cycle even when the MPP is reached, resulting in
loss of power.
The Incremental Conductance algorithm is an improvement
to the Perturb & Observe Algorithm. This algorithm ensures
higher accuracy and efficiency specially under varying
atmospheric conditions. In spite of these advantages there
are few drawbacks of this algorithm such as higher response
time and it is also not economical for small scale PV plants
[6]. The maximum power point is being tracked by the
Incremental Conductance algorithm by means of comparing
the module‘s instantaneous I-V characteristics and its
incremental conductances (dI/dV). This algorithm can
determine the distance to the MPP and thereby stop the
perturbation and tracking procedure after it has reached the
MPP [14]. The flowchart of the Incremental Conductance
algorithm can be found in Figure 8. At maximum power
point the slope of the P-V curve is equal to zero[7]. The
following equations show these characteristics:
0
dP
dV
(12)
( . ) 0
dP d V I dI dV dI
V I V
dV dV dV dV dV
(13)
Furthermore :
dI I
dV V

(14)
start
Mesure I(k), V(k)
ΔP=I (k)*V(k)
ΔP=P(k)-P(k-1)
ΔP> 0
V(k)-V(k-1)> 0
Increase V
P(k-1)=P(k)
V(k-1)=V(k)
No
No
Yes
Decrease V
Decrease V
Increase V
NO
Yes
Yes
V(k)-V(k-1)> 0
Figure 7 : P&O Algorithm
Figure 6 : MPPT schematic block diagram
3.3HUWXUEDQG2EVHUYH32$OJRULWKP
3.,QFUHPHQWDO&RQGXFWDQFH,&$OJRULWKP
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
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Volume 5, 2023
In conclusion for Incremental Conductance algorithm,
, at MPP
, left of MPP
, right of MPP
dI I
dV V
dI I
dV V
dI I
dV V

Conventional methods of tracking the optimal point of
operation have shown their limits to sudden changes of
weather and the load connected to the panel, several
methods have emerged to try to alleviate these shortcomings
and improve the operation of these generators. The approach
of Artificial Intelligence in the case of fuzzy logic is
implemented to improve control performance and the
pursuit of maximum power point by simulation and
modeling of a controller based on fuzzy logic [5][13]. The
advent of microcontrollers has enabled the spread of fuzzy
control in the pursuit of optimal points during the last
decade[9].
The fuzzy controller has the following three blocks:
Fuzzification of input variables by using the trapezoidal and
triangular functions, then these variables fuzzification
inference or are compared with predefined packages to
determine the appropriate response. And finally the
defuzzification to convert the subset fuzzification into
values using the centric defuzzification. The five linguistic
variables used are: NB (Negative Big), NS (Negative
Small), ZE (Zero Approximately), PS (Positive Small), PB
(Positive Big) [14][15]. The two FLC input variables are the
error E and change of error CE at sampled times k defined
by [13]: The operation of this algorithm is done in three
blocks:
fuzzification, inference and defuzzification (figure 9).
Where P(k) is the instantaneous power of the photovoltaic
generator. The input
()k
shows if the load operation point
at the instant k is located on the left or on the right of the
maximum power point on the PV characteristic, while the
input
()k
t
expresses the moving direction of this point.
Table 2 : Fuzzy logic rules
t
PB
PS
ZE
NS
NB
PB
ZE
ZE
NB
NB
NB
PS
ZE
ZE
NS
NS
NS
ZE
NS
ZE
ZE
ZE
PS
NS
PS
PS
NS
ZE
ZE
NB
PB
PS
PB
ZE
ZE
start
Mesure I(k), V(k)
ΔI=I (k)-I(k-1)
ΔV=V(k)-V(k-1)
ΔV=0

ΔV>0
ΔV>0
Increase V
P(k-1)=P(k)
V(k-1)=V(k)
Yes
No
No
Yes

 +
Decrease V
Decrease V
Increase V
NO
Yes
Figure 8 : Incremental Conductance Algorithm
Figure 9
: Step of Fuzzy logic
3.)X]]\ORJLF
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
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Volume 5, 2023
888888888888888888888888888888888888888888888888
88888888888888888888888888////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////
//
Bidirectional DCDC converters are used to perform the
process of power transfer between two dc sources in either
direction. They are widely used in various applications. A
bidirectional DC-DC converter is an important part of
standalone solar Photovoltaic systems for interfacing the
battery storage system. The circuit is operated in such a way
that one switch, one coupled inductor and three diodes are
used for step-up operation to boost the voltage of the battery
to match the high voltage dc bus. The other switch,
remaining diode and simple inductor are used for step down
operation to charge the battery from the surplus PV energy.
The high efficiency of the converter is achieved by
optimizing components used for each step. The bidirectional
DC-DC converter with high power rate plays a key role in
the power storage system, while it converts DC voltage or
DC current for the power storage battery. The Bidirectional
DC-DC converter operates either as a buck or as boost
converter at any instance. It works as a buck converter for
charging the battery whereas it operates as a boost converter
[12] while the battery discharges power to the load.
From figure 14 it can be seen that the PV voltage source has
immediately next to it a boost converter stage powered by
MPPT controller which will step up the PV voltage to the
desired DC bus voltage extracting maximum power from the
PV system at every instance of operation. It is then followed
by a couple of IGBTs and a battery acting as a secondary
source. The Bidirectional DC-DC converter operation is
carried out through these two IGBTs which are controlled
by two different controllers. One controller provides the
control signal for Boost operation and the other provides the
control signal for Buck operation. It operates as a buck
converter for charging the battery through the switching
actions performed by the switch S3. On the other hand its
operation as a boost converter is dictated by the switching
actions of the switch S2 .
For the proper functioning of the hybrid energy system, the
storage system plays a crucial role, it allows for continuity
of service and better quality of energy supplied. We recall
some electrical parameters used to characterize a battery,
these are:
Nominal capacitor (Qn): This is the maximum number of
ampere-hours (Ah) that can be extracted from the battery,
for given discharge conditions.
The state of charge “SOC” (State Of Charge): This is the
ratio between the capacity at time q(t) and the nominal
capacity Qn, is :
()
( ) , with (0 1)
qt
SOC t SOC
Qn
(15)
If SOC=1 the battery is totally charged and if SOC=0 the
battery is totally discharged.
The charging cycle (or discharging): This is the parameter
which reflects the relationship between the nominal capacity
of a battery and the current at which it is charged (or
discharged). It is expressed in hours.
•Cycle life : This is the number of charge/discharge cycles
that the battery can sustain before losing 20% of its nominal
capacity.
By analyzing the figure above, we can see the presence of
three specific points on the characteristic (Q-V): these three
points are: the full load voltage (E0), the voltage
corresponding to the end of the exponential zone ( Eexp)
and the corresponding voltage at the end of the nominal
zone (En).
The charge and discharge equations are given as follows :
*Discharge :
*
B 0 t exp(t)
t
Q
E = E - Ri - K (i +i )+E
Q-i
(15)
*Charge :
*
B 0 t exp(t)
tt
QQ
E = E - Ri - K i -K i +E
Q-i Q-i
(15)
With :
exp(t) exp(t)
E = B i(t) .(-E ( ))Asel t
Figure 12 shows the discharge characteristic of the storage
system used and the evolution of its voltage for different
discharge currents.
Figure 10 : Diagram of Photovoltaic system with Battery
storage using bidirectional DC-DC converter
figure 11 : Battery discharge curve
Figure 12 : Battery voltage characteristic for different
discharge currents.
4. Battery Storage
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
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E-ISSN: 2769-2507
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Volume 5, 2023
The bidirectional DC DC converter is a combination of
boost and buck converters. Such a converter is used to
charge and discharge the battery.
The boost mode is applied for the discharging procedure of
the battery storage. Figure shows the circuit of the boost
mode operation of the converter, where the direction of the
inductor current is from the lower voltage side to the
higherK1 voltage side . The averaged large signal inductor
current,
L
i
, and the DC-bus output voltage,
Vdc
, in a
continuous conduction mode (CCM) of operation can be
found using the equations below.
is closed
10
K0
and is open
11
K1
.
B
di
Ldt B dc
VV
(14)
The buck mode is applied for the charging process of the
battery storage. Figure presents the circuit of the buck
mode operation converter. In contrast to the buck mode
operation, the inductor current flows from the
higher voltage side to the lower voltage side . The
averaged large signal inductor current,
L
i
, and the output
battery voltage,
B
V
, are calculated by the equations below,
and describe the buck-mode operation in a CCM of the
converter.
is open
10
K1
and is closed
11
K0
B
di
Ldt B
V
(15)
By analyzing these two configurations, we can conclude that
the relationships between the input quantities
( , )
BB
Vi
and
the output quantities
( , )
dc B m
Vi
of the converter are given by
the system of equations below
11
11
(1 )
(1 )
BB dc
B m B
di
L V V u
dt
i I u

(16)
Due to the intermittent and fluctuating character of hybrid
systems (pv and wind), the voltage at the DC bus will be
disturbed and fluctuating. This is why the DC bus voltage
must be kept constant at its reference. In this case, the value
of this voltage
dc
V
must be well chosen for proper operation
of the PV system connected to the grid.
The capacitor at the input of the inverter has two essential
tasks:
a) In steady state, it keeps the DC bus voltage constant with
low oscillations.
b) it serves as an energy storage element to compensate for
the difference in actual power between the load and the
source during transient periods.
Figure 13 shows the DC bus voltage regulation loop to
generate the reference power. The DC bus control generates
the fluctuating power in the DC bus capacitor, subtracted
from the power at the output of the inverter, giving us the
reference active power that must be fed into the grid. A
dynamic reference of reactive power, allows us for small
powers to impose a zero reactive power.
The DC power is :
.
dc dc dc
P I V
(17)
Then :
2
1.
2dc
dc dc dV
PC
dt
(17)
dc
C
: the DC bus capacitor.
So :
Figure 13 : Circuit of the DCDC bidirectional converter
figure 14 : Quadratique control of DC bus
4.1 Boost Mode
4.2 Buck mode operation
4.3 Quadratic DC bus control
International Journal of Electrical Engineering and Computer Science
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Volume 5, 2023
22
( ) ( 1) ( ( ) ( )
dc dc pv
dc
Te
V n V n P n P n
C



(17)
Te : Sampling period
The control strategy is divided into two blocks the first is for
the calculation and the second is reserved for the control.
All simulations and results, of the previous algorithms
studied, were performed under the same condition to ensure
that the circuit comparison can be determined accurately.
Input, output, voltage, current, and power are the primary
comparison to consider. The complexity and simplicity of
the circuit was determined on the basis of the literature.
Convergence speed, required hardware and efficiency range.
Table 3 takes an illumination of 1000 and a temperature of
25 as the initial value.
Table 3: Electrical characteristic of PV panel
Size
Value
Open circuit voltage Voc (V)
36.3
Voltage at maximum power point Vmp(V)
29
Short-circuit current Isc (A)
7.84
Current at maximum power point Imp (A)
7.35
Diode saturation current Is (A)
2.9259 e-10
Shunt resistance Rp (ohms)
313.3991
Series resistance Rs (ohms)
0.39383
Maximum power point tracking
213.15
Series-connected modules per string Ns
1
Parallel strings Np
5
The irradiation equals
2
1000 /Wm
and the battery current is
around -20 A. The state of charge (SOC) is increasing so it
means the battery is charging and PV side power is 1000W.
The Bus voltage is around 48 V.
When the irradiation is decreased
2
700 /Wm
the battery
current is decreased around -10A. The moment of the
changing irradiation the system is unstable and then a few
seconds later the system returns stable.
Decreasing the irradiation of
2
400 /Wm
the battery current
is zero.
We can say the battery is disable.
I want to decrease irradiation to
2
0/Wm
and the battery
current is around 15 A. The state of charge (SOC) is
decreasing so it means the battery is discharging and PV
side power is
2
0/Wm
. Then the PV power is disabled.
When the irradiation is equal
2
400 /Wm
the SOC is stable
and the current battery is zero. So the battery is disable.
When we increase the irradiation to
2
600 /Wm
the battery is
charging because the SOC is increasing and the battery
current is negative. PV power is increasing.
Then the bus voltage is constant.
Figure 15 : Characteristic of pv with battery based on Perturb & Observe algorithm
5. Simulation and result
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
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Volume 5, 2023
Figure 16: Characteristic of pv with battery based on incremental Conductance algorithm
Figure 15 : Characteristic of pv with battery based on Fuzzy logic algorithm
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
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Volume 5, 2023
Moreover, to evaluate the performance the proposed MPPT,
the PV is exposed to different levels of irradiance that is
changed randomly and rapidly (although normal solar
irradiance does not abruptly, but this would happen in
partially shaded PV systems. According to the obtained
results presented in Figures 15,16 and 17 the MPPT
algorithm tracks the values of maximum power. In each
case, the power extracted from the PV is well controlled.
The results prove that the convergence speed is relatively
high.
To evaluate the performance of the PV with load, a
comparison between the three methods of MPPT with
battery storage. PV maximum
power and that computed from the algorithm is carried out
for different values of solar irradiance and the results are
plotted . Moreover, the corresponding tracking efficiencies
of the proposed MPPT under different irradiance levels are
computed and presented in the figures of the simulation
part..
According to the obtained results, the tracking efficiency is
not less than 95 %.
Therefore, the proposed method guarantees good tracking
efficiency under different operating conditions.
Discussion:
* The P&O algorithm is a classic and simple algorithm. In
general, this algorithm depends strongly on the initial
conditions and it oscillates around the optimal value. The
major drawback of this algorithm is its poor behavior
following a sudden change in illumination (clouds).
* The INC algorithm appears to be an improvement of the
P&O algorithm. Indeed, it behaves better during a rapid
change of meteorological conditions. However, this is a
more complex algorithm than the previous one. Algorithms
based on measuring a fraction of open circuit voltage or a
fraction of short circuit current are very simple and easy to
implement. The major drawback is the loss of energy and
the stopping of power transfer when measuring the
quantities Voc and Isc. To overcome this problem, a pilot
cell of the same type as the panel cells is used. In addition,
determining the optimum value of the parameter k is very
difficult. Therefore, these methods seem just an
approximation and they do not have enough precision and as
a result the system does not always perform at the optimum
point.
* The fuzzy logic algorithm is a robust and efficient
algorithm. Indeed, this algorithm works at the optimal point
without oscillations. In addition, it is characterized by good
behavior in transient state. However, the implementation of
this type of algorithm is more complex than traditional
algorithms. In addition, the efficiency of this algorithm
depends heavily on the inference table. The following table
summarizes the main specifications of the various MPPT
algorithms previously studied. We evaluated and compared
these algorithms in terms of technical knowledge of PV
panel parameters, complexity, speed and precision.
Also the battery characterized is changed with the variation
of irradiation and the change of three MPPT algorithms .
We can conclude that both the boost converter and the
battery are affected by the mppt algorithm.
This work describes the main elements of the PV system.
Then, we recalled the principle of three most popular MPPT
algorithms. Finally, we ended with a simulation of the
different algorithms. The simulation results show that the
INC algorithm performs better than the P&O and the fuzzy
logic based control shows good behavior and better
performance compared to the P&O, INC. These algorithms
improve the dynamics and steady state performance of the
photovoltaic system as well as it improves the efficiency of
the dc-dc converter system.
At the end of this work, several direct perspectives are
announced and the following points are quoted by way of
illustration :
network.
PV system. -tolerant control algorithms.
[1] A.Pradeep Kumar Yadav, S. G. (2012). Comparison of
MPPT Algorithms for DC-DC Converters Based PV
Systems . International Journal of Advanced Research in
Electrical, Electronics and Instrumentation Engineering .
[2] Cylia TIGRINE,Ouerdia Ait Ouali.(2018/2019). Etude et
simulation des techniques MPPT d’un système
photovoltaïque. République Algérienne Démocratique et
Populaire Ministère de l’Enseignement Supérieur et de la
Recherche Scientifique UniversitéA.MIRA-BEJAIA.
[3] Djamila Rekioua, T. R. (2015). Control of a Grid
Connected Photovoltaic System. 4th International
Conference on Renewable Energy Research and
Applications. Palermo, Italy.
[4] Hanen Abbes, H. A. (2013). Etude comparative de cinq
algorithmes de commande MPPT pour un système
photovoltaïque . Conférence Internationale des Energies
Renouvelables (CIER’13) . Sousse Tunisie.
[5] Unal Yilmaza, A. K. (2018). PV system fuzzy logic
MPPT method and PI control as a charge controller.
Elsevier , 994-1001.
[6] William Christopher, D. 1. (2013). Comparative Study
of P\&O and InC MPPT Algorithms . American Journal of
Engineering Research (AJER) , 402-408 .
[7] F. Ansari ,A. K. Jha, Maximum power point tracking
using perturbation and observation as well as incremental
conductance algorithm international journal of research in
engineering \& applied sciences, issn: 2294-3905, PP 19-
30,2011.
[8] B. S, Thansoe, N. A, R. G, K. A.S., and L. C. J., "The
Study and Evaluation of Maximum Power Point Tracking
6. Conclusion
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DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
20
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International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2023.5.3
Achwak Alazrag, L. Sbita
E-ISSN: 2769-2507
21
Volume 5, 2023