APPLICATION OF INTELLIGENT CONTROL
SYSTEM FOR MAXIMUM POWER EXTRACTION
(MPE) OF PV POWER SYSTEM UNDER PARTIAL
SHADE CONDITION
BY : Getnet Mekonnen Alemu
February 10 , 2021

 Introduction
 Statement of The Problem
 Objectives
 Significance of The Study
 Literature Review
 Methodology
 Modelling of The System
 Equivalent Circuit of PV Cell
 Designing of MPPT Using Fuzzy Logic Control
 Results and Discussion
 Conclusion and recommendation
Outline

INTRODUCTION
Solar PV power system is a competitive source of electricity
growing at a rapid rate due to the reason abundantly available,
clean, noise and pollution free
Solar photovoltaic system is widely in use among others
alternative sources of electricity
The basic factors that contribute to the reduction of output
power from PV arrays are :
 Radiation
 temperature
 partial shading and etc

 Basic challenges for efficient tracking and utilization of
PV power are :
 Low conversion of efficiency,
 Dependent on atmospheric/climatic conditions
 Partial Shading
 Non-linear characteristic
 High initial investment requirement and
 It needs techniques / controller for efficient tracking and
utilization of the available power.
Statements of the Problem

Cont.
 Some of the drawbacks of widely used classical techniques are :
 failure to track the right direction of perturbation,
 Problems on steady-state oscillation and
 failure to track GMPP under partial shade condition
 Therefore we need to effectively tracking at GMPP, minimize
power loss and also improve the above drawbacks

General Objective:
The general objective of this thesis is:
 To design and simulate FLC for MPPT of PV power
system under partial shade condition.
Specific Objectives;
The specific objectives of this thesis are :
 To identify forms of utilization, basic tasks and components
required for efficient tracking of PV power system
 To develop fuzzy-logic based MPPT algorithm that is able to
respond quickly during partial shade condition
Objectives

Cont.
 To be able operate the PV system at/near global MPP under
partial shade
 To perform the Simulation of the overall PV system in
MATLAB/Simulink.
 To compare the fuzzy-logic based algorithm to the classical
methods.

This thesis will provide the following significances
 Better utilization of solar power system
 Increases reliability and availability of electrical energy
 Increase life span of the solar system components
 Decreases energy consumptions
 Increases the ability to maintaining MPPT during partial
shading condition
 Improving the quality of the controller
 Evaluate the performances of MPPT based on the simulation results
and etc
Significance of the study

 Some of basic studies done in related to MPPT system are
given below on the next table:
Year and
Name of
the authors
Title Benefits Draw backs
In 2017 Dr.
R. Sankar
et al
A PV system
using fuzzy
logic and a dual-
MPPT
controller
opposite direction
leading to
oscillations and
also improve the
efficiency during
Uniform shading
It is not
considered the
partial shading
conditions of
PV of solar
Literature Review

cont…
Year and
Name of
the
authors
Title Benefits Draw backs
In 2017
Palliva
Verma et
al,
Comparison of
intelligent and
classical MPPT
(P&O) algorithms
for PV system
under Partial
shading
During STC
good output
power and
Partial
shading is
considered.
Power output
value is below
the expectation
during Partial
Shading.
Tests only a
single string .

cont…
Year and
Name of
the
authors
Title Benefits Draw backs
In 2017 S.
Malathy
and R.
Ramaprabh
a
MPPT Algorithm of
SPVA (solar PV array)
under Inhomogeneous
Irradiation Conditions:
a Modified Fibonacci
Search Based
Approach
Easy to
implemen
t in
experimen
tally
Its more of classical
methods that is it
takes high settling
time and tests only
radiation change but
not temperature
factors
In 2013
Lixia Sun
et al
proposed that MPPT
with fuzzy control
then Compared with
the conventional
achieves
better effect
in terms of
speed
Its not effective for
partial shading
conditions.

Year and
Name of
the authors
Title Benefits Draw backs
In 2017
Mahima
Sunar and
et.al,
"Study of Intelligent
MPPT Controllers
for a Grid
Connected PV
System
For grid system its
good output had
performed
Not implement on
the off grid system
but the current
problem is for the
off-grid system in the
rural area
In 2014, P.
Srinivasa
Rao
Comparison of
different
interconnection
schemes based
on shading
conditions and
shading levels
Very Easy due
to only consider
the
interconnection
schemes (there
is not have extra
algorithm /
controller) .
Control system is
not accurate. Or
it’s classical
control system
and only focused
on
interconnection
schemes
Cont…

Methodology
1
• Conduct literature review: I had been reviewed
some of related to the problem intended to address
and to refine more the approaches to solve the
problems and result presentations.
2
• Modeling Photovoltaic System : I had been modeled
the MPPT controller on the considerations of partial
shading, efficiency, atmospheric conditions , accuracy
and etc
3
• Develop the Algorithm: I had been developed the
algorithm by considering of the error, steady-state
oscillation and tracking at the global MPP under
partial shade condition

Cont.
4
• Design of Photovoltaic System: To verify
performance of the proposed model by comparison
with the classical one.
5
• Simulation : the proposed controller algorithm and
design will be done using MATLAB/Simulink
modeling and simulation
6
• Result and Discussion : According to the design
and simulation the result will be briefly explained

Modeling Photovoltaic System
PV Cell generates power by converting sunlight to
electricity.
 The electric current generated is proportional to solar
radiation.
To extract the maximum power from PVs, their
mathematical model , which can predict their nominal
voltage and nominal current, should be investigated
Modelling of The System

Equivalent circuit of PV cell
The equivalent circuit of a PV cell includes diode, shunt
resistance, series resistance representing an internal resistance
to current flow and current source is illustrated in Figure
below
Using an equivalent circuit diagram, i.e. a current source in
parallel with a diode.
Further addition of components like series, parallel resistor
and parallel diodes are to improve accuracy of simulation

On the above equivalent circuit diagram representation a single
diode five parameters (Rsh) model is widely used being a
compromise in simplicity and accuracy
Cont...
Ideal PV cell is modeled as a solar irradiance dependent current
source, Iph is parallel with a diode.
The photocurrent depends on solar radiations and affected by
cell’s operating temperature (Tc) which given as in the eq 3-1
below:

 The basic equation from the theory of semiconductors
that mathematically describes the I–V characteristic of the
PV cell are given in Eq 3-2 to 3-7 :
Cont...

Cont...

cont…

Fig: Modeling diagram of the characteristics
equations
Cont...

Designing of MPPT using fuzzy logic control
FLC based MPPT technique can be formulated with different
options of input/output parameters of the PV system.
The input parameters can be error (E) and change in error ΔE or
change in PV power (ΔP) and change in PV voltage (ΔV) or
change in PV current ( ΔI)
The output of change in duty cycle (ΔD) reference voltage
(ΔVref) or change in reference current (ΔIref)

The second possible option with inputs of ΔVpv and ΔPpv
is supposed to solve the drawbacks of FLC based MPPT technique
using error and change in error inputs, can be described using
expressions in equations below:
Block diagram of FLC MPPT algorithm
Cont...

Figure : Flow chart algorithims of FLC MPPT with the I/O of the
above two cases
Cont...

 FLC based MPPT with inputs of PV voltage and power
variation and output of a change in reference voltage mapped each
I/O to 7 different linguistic variables, a total 49 rules and
input/output membership functions are given below on the table:
Cont...
↓∆V/∆P→ NB NM NS ZR PS PM PB
NB NB NM NS ZR PS PM PB
NM PB PB PM ZR NM NB NB
NS PB PM PS ZR NS NM NB
ZR PM PS PS ZR NS NS NM
PS NB NM NS ZR PS PM PB
PM NM NS NS ZR PS PS PM
PB NB NM NS ZR PS PM PB
If the input ∆V is NB and ∆P is NB then the output is NB
If the input ∆V is NB and ∆P is NM then the output NM

Block diagrams of FLC based MPPT

if dI/dV > -I /V , thus V <V max
;
if dI/dV < -I /V , thus V >V max
if dI /dV = - I/V , thus V =V max ;
Algorithms of Incremental conductance

Fig: Schematic diagrams of a single PV string

Fig: Schematic diagrams of a multiple PV string

On this section the results of the proposed controller is
compared with the classical InCond, basically I use five
basic factors/conditions PV system, these are:
 Variable Temperature
Variable Irradiations
Both temperature and Irradiations are variable
Constant Temperature but variable Irradiations
Constant Irradiations but variable temperature
Results and Discussions

0 50 100 150 200 250
0
200
400
600
800
Voltage (V)
Power(W)
Case1 Higher Range
Case 2 Medium Range
Case 3 Lower Range
Fig: Outputs of Constant radiation with variable temperature value
0 50 100 150 200 250
0
100
200
300
400
500
600
700
800
900
VOLTAGE (V)
POWER(W)
constant Rad.but Varaible T
during STC
both T & Rad are varyed
Constan Tbut Variable Rad
Fig : Comparative output value of different cases
Cont...

0 50 100 150 200 250 300
-2
0
2
4
6
8
10
voltage (v)
current
(A)
SP1
SP2
SP3
SP4
Fig : I-V Characteristics curve using FLC
Parameters of different Shading patterns (SP) for simulation purpose

0 20 40 60 80 100 120
0
200
400
600
800
1000
Voltage (V)
Power(w)
Using InC US
SP1
SP2
SP3
SP4
0 50 100 150 200 250
0
100
200
300
400
500
600
700
800
900
Voltage (V)
Power
(w)
SP4
SP3
SP2
SP1
US
SP4
SP3
SP2
SP1
Using FLC Uniform Shading
Figure : MPPT with different shading patterns of P-V Trajectories
Cont...

Table : MPPT value using FLC and InCond algorithm
Table: Efficiency of different shading pattern of the proposed
controller and InCond:
Shading Patterns FLC InCond
SP1 99.9976% 95.4433%
SP2 99.9889% 95.4433%
SP3 99.9879% 94.7857%
SP4 99.9998% 97.7773%

Table: Comparison of MPPT deviation of FLC and the classical one
The deviation records revealed that capability of FLC to
track the GMPP accurately than classical methods
Cont...

steady state performance
Step change from SP3- to –SP4
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
0
100
200
300
400
500
600
700
Time(sec)
power(W)
Output power using FLC
Expected power value
0.025 0.03 0.035 0.04
627.5
628
628.5
629
629.5
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.4
0
100
200
300
400
500
600
700
Time(sec)
power(W)
SP3
SP4
During step change from shade pattern4 to shade pattern3 (SP4 to SP3)
at t=0.25second there is search range to locate GMPP
Using FLC technique shows very small search range , small amplitude
of oscillation and low steady-state error than the InCond
Cont...

CONCLUSIONS
During partial shading conditions, the PV characteristics
curve comprises of multiple local and global peaks.
Accordingly performance evaluations for a given shade
patterns of a PV system have been done and tracks the GMPP
of PV systems under partial shade conditions.
According to the above simulations results I concluded that
the proposed controller has the following benefits than the
classical one :
faster response,
accurate global peak power tracking
capability, low steady sate oscillation,
higher performance and
higher tracking efficiency as compared to the InCond
algorithm techniques

Recommendations
Solar photovoltaic system is widely in use among others
alternative sources of electricity and currently it’s a new technology
and a highly demand in the world, there fore I want to recommend
that :
Further research will be done in the combination of intelligent
control algorithms and classical control methods
On the future work, I will recommend that better to do the
hardware implementation using microcontroller in experimentally
to confirm the performance of proposed algorithm

???
Thank you !!!