Internati
o
nal
Journal of Ele
c
trical
and Computer
Engineering
(IJE
CE)
V
o
l.
6, N
o
. 2
,
A
p
r
il
201
6, p
p
.
56
7
~
58
2
I
S
SN
: 208
8-8
7
0
8
,
D
O
I
:
10.115
91
/ij
ece.v6
i
2.9
204
5
67
Jo
urn
a
l
h
o
me
pa
ge
: h
ttp
://iaesjo
u
r
na
l.com/
o
n
lin
e/ind
e
x.ph
p
/
IJECE
A Review on Phot
o Volt
aic MPP
T
Algori
t
hms
Sa
ra
va
na
Selva
n
*
,
Prat
ap Na
ir*
,
Umaya
l**
* Faculty
of
Eng
i
neer
ing and
Co
mputer Technolog
y
,
AIMST Un
iversity
, Bedong
, Ked
a
h, Malay
s
ia
** Graduated
in
Anna University Chennai, India
Article Info
A
B
STRAC
T
Article histo
r
y:
Received Aug 12, 2015
Rev
i
sed
No
v
25
, 20
15
Accepted Dec 16, 2015
A
photovoltaic generator exhibits
nonlin
ear vo
ltage-
curren
t
ch
aracteristics
and its maximum power point varies
with
solar radia
tio
n and cel
l
temperatur
e. A
Dc/Dc power
converter
is used
to match
the p
hotovoltaic
s
y
stem to the load and to operate
th
e PV (photo voltaic) cell array
at
ma
xi
mum po
we
r poi
nt
.
Ma
xi
mum Po
wer Poi
n
t Tracking (M
PPT) is a
process which tracks one maximum po
wer p
o
int from PV
array
inpu
t,
var
y
ing th
e rat
i
o
between
the v
o
ltag
e
and curr
e
n
t deliv
ered
to
get the m
o
st
power it can.
Th
ere ar
e diff
eren
t techn
i
ques prop
osed with lot of
algorithms
are be
ing us
ed i
n
the M
P
P
T
controlle
r to ext
r
ac
t
the m
a
xim
u
m
power.
It is
ver
y
diff
icul
t f
o
r the pho
to v
o
ltai
c
d
e
s
i
gners
,
res
ear
chers
an
d ac
adem
ic
experts to select a partic
ular M
PPT technique
for a particu
l
ar
application
which requires
the backgroun
d knowledge and comparative features of
various MPPT algorithms
. This
paper will be av
aluab
l
e source f
o
r those who
work in the pho
to volta
ic g
e
ner
a
tion
,
so
its obj
ect
ive is to r
e
vi
ew the m
a
in
M
P
P
T
algorith
m
s
in practi
ce
and an
al
yz
es
th
e m
e
rits
and
d
e
m
e
rits
with
various factors.
Keyword:
Direct
Ind
i
rectIn
tellig
en
ce tech
n
i
q
u
e
s
MPPT algorithm
s
PV a
rray
Copyright ©
201
6 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
Sara
van Selva
n
,
Facul
t
y
o
f
E
n
g
i
neeri
n
g a
n
d C
o
m
put
er Tec
h
n
o
l
o
gy
,
AIMST Un
iversity,
B
e
do
n
g
, Ke
da
h,
M
a
l
a
y
s
i
a
Em
a
il: sarav
a
nan
@
aim
s
t.ed
u
.
my
1.
INTRODUCTION
Our
world
is
witn
essin
g
a lo
t
o
f
en
erg
y
crisis an
d
en
v
i
ronmen
tal p
o
llu
tion
,
t
o
so
lv
e it the ren
e
wab
l
e
energy is the
alternate sources of
e
n
er
g
y
.
Sol
a
r e
n
e
r
gy
has t
h
e a
dva
nt
age
s
o
f
m
a
xim
u
m
reserve
,
i
n
exha
ust
i
b
l
e
nes
s
, an
d i
s
f
r
ee
fr
om
geog
ra
ph
i
cal
rest
ri
ct
i
o
n
s
, t
h
us m
a
ki
n
g
ph
ot
o
v
o
l
t
a
i
c
(P
V)
t
ech
nol
ogy
a
po
p
u
lar resea
r
ch topic. C
u
r
r
e
ntly
m
o
re research
wo
rk
s has been foc
u
ss
ed on ho
w to
extract m
o
re powe
r
effectively from the PV cells. At co
nst
a
nt
uni
f
o
rm
i
rrad
i
ance, t
h
e P
V
array has a current
-
voltage
(I-V)
ch
aracteristic lik
e th
at sho
w
n in
fi
gu
re
1. In that curve, t
h
ere is a
un
iqu
e
po
in
t called
t
h
e m
a
x
i
m
u
m
p
o
wer
poi
nt
(M
PP
),
at
whi
c
h t
h
e
array
operates
at
m
a
xim
u
m efficiency
and
pr
odu
ces outp
u
t
pow
er
. B
u
t th
e
p
r
ob
lemis wh
en
t
h
e PV array
is d
i
rec
tly conn
ected to
a lo
ad
, t
h
e system
op
erating
po
in
t
is no
t ex
actly at th
e
MPP rath
er than
th
at th
e in
tersectio
n of th
e
I-V curv
e
of the PV array an
d lo
ad
lin
e can happe
n
as
s
hown i
n
figu
re 1. An
d also
at th
e ti
me o
f
p
a
rtially sh
ad
ed
cond
itio
n
or ch
ang
e
in
weat
h
e
r co
nd
itio
n
s
i.e, so
lar
irradiation a
nd atm
o
spheric t
e
m
p
eratur
e, t
h
e syste
m
can
not
operate at
th
e PV a
rray
MPP.
It is
not
ed that
u
n
d
e
r p
a
rtial sh
ad
i
n
g
con
d
itio
n
s
, th
e P-V ch
aracteristics
of th
e PV array g
e
t m
o
re co
m
p
lex
and
b
e
ar mu
ltip
l
e
peak
s as
sh
o
w
n i
n
fi
gu
re
1.
To
o
v
erc
o
m
e
thi
s
pr
obl
em
, M
a
xi
m
u
m
power
p
o
i
n
t
t
e
c
h
ni
q
u
es
(M
PPT
) are
em
pl
oy
ed
i
n
ph
ot
o
v
o
l
t
a
i
c
syste
m
s to
m
a
k
e
fu
ll u
tilizati
o
n
o
f
PV array
o
u
t
p
u
t
pow
er
[1-5
]. Max
i
m
u
m Po
wer Po
i
n
t Track
i
n
g
(MPPT) is
a pr
ocess
w
h
i
c
h t
r
ac
ks o
n
e
m
a
xim
u
m
po
wer
p
o
i
n
t
(M
P
P
) f
r
om
ph
ot
o
vol
t
a
i
c
(P
V)
array
i
n
put
.
T
h
e m
a
i
n
ch
allen
g
e
b
y
MPPT techn
i
qu
es is t
o
au
tomatical
ly fin
d
th
e vo
ltag
e
V
M
PP
or c
u
r
r
ent
I
M
PP
at which a PV a
rray
sh
ou
l
d
o
p
e
rate
to
ob
tain
t
h
e m
a
x
i
m
u
m
p
o
w
er ou
tpu
t
P
MPP
un
der
a
gi
ve
n t
e
m
p
erat
ure a
n
d
i
rradi
a
n
ce
[1
-
2
]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
IJEC
E V
o
l
.
6, No
. 2, A
p
ri
l
20
16
:
56
7 – 5
8
2
56
8
In
o
r
de
r t
o
l
o
c
a
t
e
an
d t
r
ac
k t
h
e M
P
P
of
t
h
e
PV
ar
ray
,
MPPT algorit
h
m
s
are
used
in th
e techn
i
qu
e.
Sev
e
ral
t
echni
q
u
es
an
d
al
g
o
ri
t
h
m
s
ha
ve
bee
n
pr
op
os
ed i
n
t
h
i
s
area
t
o
ove
rc
om
e t
h
e d
r
aw
bac
k
s
of
t
h
e s
o
l
a
r
P
V
s
y
st
em
[3
-5]
.
T
h
e M
a
xim
u
m
Powe
r Point Trac
kin
g
(M
PPT) is us
ua
lly u
s
ed
as o
n
lin
e co
n
t
ro
l
strateg
y
to
track
the
m
a
xim
u
m
out
put
po
we
r o
p
e
rat
i
ng
p
o
i
n
t
of t
h
e P
hot
ov
ol
t
a
i
c
gene
rat
i
on
(P
V
G
)
fo
r
di
ff
ere
n
t
o
p
e
r
at
i
n
g
con
d
i
t
i
on
of i
n
sol
a
t
i
o
n an
d
t
e
m
p
erat
ure
of t
h
e
PV
G.
Ho
hm
D, R
opp M
c
o
m
p
ares and e
v
al
ua
t
e
s t
h
e
perce
n
t
a
ge
of
po
we
r ext
r
act
i
on wi
t
h
M
PPT and wi
t
h
o
u
t
M
PPT [22]
.
Her
-
Ter
n
gYa
u
[23]
uses t
h
e
M
PPT
tech
n
i
qu
es
with
th
e PV syst
e
m
fo
r
op
ti
m
a
l ch
arg
i
ng
o
f
Li
-i
on B
a
t
t
e
ry
.
T
he a
u
t
h
ors
[
2
4]
[2
5]
p
r
o
p
o
s
e
s t
h
e
m
odi
fi
ed t
w
o b
a
si
c M
PPT al
gori
t
h
m
s
l
i
k
e pert
ur
b an
d o
b
se
r
v
e an
d Inc
r
em
ent
a
l
con
duct
a
nce w
h
i
c
h sh
o
w
s t
h
e
l
a
t
e
r one i
s
ver
y
com
p
l
e
x t
o
i
m
pl
em
ent
and
t
h
e fo
rm
er one
i
s
very
easy
t
o
im
pl
em
ent
but
not
rel
i
a
bl
e
.
S
a
l
a
m
Zai
n
al
[8]
an
al
y
zes t
h
e per
f
o
r
m
a
nce of s
o
ft
com
put
i
n
g
based M
P
P
T
al
gori
t
h
m
s
unde
r pa
rt
i
a
l
shade
d
co
nd
itio
n wh
ich
creates a tran
sien
t
ou
tpu
t
in
h
i
s
work. Th
e ap
p
lication
o
f
in
tellig
en
t t
ech
n
i
q
u
e
s lik
e fu
zzy
l
ogi
c,
neu
r
al
n
e
t
w
o
r
k i
n
t
h
e
M
PPT t
ech
ni
q
u
e t
o
t
r
ac
k t
h
e
M
PP i
s
achi
e
ved
by
t
h
e
res
earhe
rs i
n
t
h
i
s
pape
r
[2
7]
.
Figure
1. PV-IV Characteristi
cs of
uni
form
sola
r irra
diance
and under pa
r
tial sh
ad
ed conditio
n
[1
]
There a
r
e lot
of MPPT trac
ki
ng tec
hni
ques
are in
practice
and t
h
e com
p
a
r
ison of m
o
st of t
h
e MPP
T
t
echni
q
u
es
wi
t
h
resp
ect
t
o
t
h
e am
ount
of
e
n
er
gy
e
x
t
r
act
e
d
fr
om
t
h
e P
V
pan
e
l
ha
ve
been
pr
op
ose
d
i
n
t
h
e
literatu
re [1
-5
]
.
W
ith
t
h
is in
min
d
,
th
ere are m
a
n
y
MPPT alg
o
rith
m
s
h
a
v
e
b
e
en
d
e
velo
p
e
d
an
d in
t
e
n
s
iv
e
researc
h
has been carried
out
to optim
ize the techniques.
The
pape
r re
vi
ews t
h
e va
ri
ous M
PPT al
g
o
ri
t
h
m
t
echni
q
u
es t
h
at
ha
ve bee
n
use
d
f
o
r
P
hot
ov
ol
t
a
i
c
sy
st
em
at
chan
ges i
n
i
r
rad
i
ance an
d t
e
m
p
erat
ure
.
It
di
sc
usses
the technical a
s
pects, m
e
rits,
dem
e
rits and a
n
alyzes the
pe
r
f
o
r
m
a
nce of
ea
ch m
e
t
hod
.
It
i
s
very
di
f
f
i
c
ul
t
fo
r
the Photo
volt
a
ic designe
rs,
researc
h
ers and academ
ic experts to select
a particular M
PPT technique
for a
part
i
c
ul
a
r
ap
pl
i
cat
i
on w
h
i
c
h
r
e
qui
res t
h
e
bac
k
g
r
ou
n
d
k
n
o
w
l
edge a
n
d c
o
m
p
arat
i
v
e
feat
u
r
es o
f
va
ri
o
u
s
M
PPT
alg
o
rith
m
s
.
Obv
i
uo
usly th
is
p
a
p
e
r
wo
u
l
d
be a
v
a
lu
ab
le so
urce
fo
r t
h
ose wh
o requ
ire m
o
re in
fo
rm
atio
n
t
o
desi
g
n
an i
m
prove
d M
PPT f
o
r i
nve
rt
ers as wel
l
as i
t
can
also provide a conve
n
ient
refe
r
e
nce f
o
r f
u
tu
re
wor
k
i
n
P
V
po
we
r g
e
nerat
i
o
n.
I
n
t
h
i
s
pa
per,
t
h
e sect
i
o
n
2
di
scusses
t
h
e
bas
i
c equi
val
e
nt
c
i
rcui
t
an
d
no
nl
i
n
ear c
h
aract
e
r
i
s
t
i
c
s of P
V
panel
i
s
di
sc
us
sed.
Sect
i
o
n
I
I
I
de
scri
be
s t
h
e
cl
assi
fi
ca
t
i
on o
f
M
PPT
Tech
n
i
ques
.
Sect
i
o
n II
I, IV & V
re
vi
ews
t
h
e w
o
rki
n
g
pri
n
ci
pl
e
of
v
a
ri
o
u
s M
P
PT
al
go
ri
t
h
m
s
b
a
sed
o
n
t
h
e
t
echni
que
a
n
d
bei
n
g
com
p
are t
h
e
perform
a
nce of each tec
h
niques with critical param
e
ters.
2.
R
E
SEARC
H M
ETHOD
A so
lar PV cell is
b
a
sicall
y
a p
-
n
ju
n
c
ti
o
n
fabricated
in
a th
in
wafer o
f
sem
i
co
nd
u
c
t
o
r. The
electr
o
m
a
g
n
e
tic r
a
d
i
atio
n
o
f
so
lar
en
erg
y
can
b
e
d
i
r
ectly co
nv
er
ted
to
electr
icity
th
r
ough
ph
o
t
o
v
o
ltaic ef
f
ect.
B
e
i
ng e
x
p
o
se
d
t
o
t
h
e s
unl
i
g
h
t
, ph
ot
o
n
s
wi
t
h
ene
r
gy
g
r
eat
er t
h
e
n
t
h
e
ba
nd
-
g
ap e
n
er
gy
of t
h
e sem
i
cond
uct
o
r
creates so
m
e
electro
n-ho
le
p
a
irs
p
r
op
ortion
a
l to
th
e in
ci
dent
i
r
ra
di
at
i
on. T
o
ac
hi
eve
hi
g
h
er
v
o
l
t
a
g
e
an
d
cu
rren
t, m
u
ltip
le cells are u
s
ed
as n
eeded. Th
e PV cell can
b
e
represen
ted b
y
a si
m
p
le
e
q
u
i
v
a
len
t
circuit with
the series re
sistance Rs re
pre
s
ents
th
e in
tern
al lo
sses
du
e
to
th
e curren
t
flow, whe
r
eas
the shunt resis
t
ance
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
A Review on
P
hot
o V
o
ltaic M
PPT Al
gorithms
(
Sar
ava
n
Sel
v
an)
56
9
Rsh c
o
rres
ponds t
o
the
leakage c
u
rren
t t
o
th
e
g
r
ou
nd
an
d it is no
rm
ally ig
n
o
red. Th
e
o
u
t
p
u
t
curren
t is a
fu
nct
i
o
n
of
sol
a
r ra
di
at
i
o
n, t
e
m
p
erat
ure,
wi
n
d
s
p
ee
d a
n
d
coefficients
t
h
at are partic
u
l
ar to
th
e cell techno
log
y
.
Th
e au
tho
r
s
[6-7
] presen
ted
a d
e
tailed
an
aly
s
is o
f
so
lar
cel
l and its electrical equivale
nt
m
odel is created in
Matlab
/
Si
m
u
li
n
k
. Th
e
n
e
t
cu
rren
t equ
a
tio
n (Eqn
1
.
1
)
o
f
th
e
PV
cell is th
e d
i
fferen
c
e b
e
t
w
een
th
e
ph
ot
oc
u
rre
nt
I
p
h
an
d t
h
e
no
r
m
al
di
ode
cu
rr
ent
I
D
.
1
exp
c
s
o
ph
D
ph
mkT
IR
V
e
I
I
I
I
I
Eq
n 1.
1
whe
r
e:
m
- Id
ealizin
g
facto
r
k
- B
o
l
t
z
m
a
nn’
s gas
co
nst
a
nt
Tc-
Absol
u
te te
m
p
erature
of t
h
e cell
e- Electronic c
h
arge
V-
Vo
ltag
e
imp
o
s
e acro
s
s th
e cell
Io
-
D
ar
k sat
u
ra
t
i
on c
u
r
r
ent
PV m
odul
es have
uni
que
cur
r
ent
v/
s
v
o
l
t
a
ge (I
-
V
)
charact
e
r
i
s
t
i
c
s. From
t
h
e P-V an
d I
-
V
ch
aracteristics, as sh
own
in fi
g
u
re
2
a
&b [5
], it is cl
ear t
h
at the PV syste
m
s
m
u
st be operated at a
m
a
xim
u
m
po
we
r
poi
nt
(
M
PP)
of
s
p
eci
fi
c cu
rre
nt
a
n
d
v
o
l
t
a
ge
val
u
e
s
so as t
o
inc
r
ease the
PV efficiency. T
h
e
volta
ge
th
at correspo
n
d
s
t
o
th
e m
o
d
u
le
m
a
x
i
m
u
m
p
o
w
er
v
a
ries wi
th
tem
p
eratu
r
e
an
d in
so
latio
n
v
a
riation
s
,
so a MPP
tracking syste
m
is neede
d
t
o
ens
u
re t
h
at we
stay
as close as
possible t
o
the
m
a
xim
u
m
power point.
Fo
r an
y PV
syste
m
, th
e ou
tp
u
t
po
w
e
r
can b
e
in
crea
sed
by trac
king the MPP
(Maxi
m
u
m
Powe
r
Poi
n
t
)
o
f
t
h
e
PV m
odul
e by
usi
n
g a co
nt
r
o
l
l
e
r co
nne
ct
ed t
o
a dc
- dc
con
v
e
r
t
e
r (
u
s
u
al
l
y
boost
co
n
v
ert
e
r
)
.
Howev
e
r, th
e
MPP ch
ang
e
s
with
in
so
latio
n lev
e
l and
te
mperat
ure due
to
the
nonlinea
r cha
r
acteristic of
PV
m
odul
es. Eac
h
t
y
pe o
f
P
V
m
o
d
u
l
e
has i
t
s
o
w
n
speci
fi
c ch
aract
eri
s
t
i
c
. I
n
gene
ral
,
t
h
ere
i
s
a si
n
g
l
e
poi
nt
o
n
t
h
e
V-I or V-P curv
e, called
th
e Max
i
m
u
m
Po
wer Po
in
t (M
PP), at wh
ich
th
e en
tire PV syste
m
o
p
e
rates wit
h
m
a
xim
u
m
effi
ci
ency
an
d
pr
o
duce
s
i
t
s
m
a
xim
u
m
out
put
p
o
we
r.
Thi
s
p
o
i
n
t
can
be
l
o
ca
t
e
d wi
t
h
t
h
e
h
e
l
p
o
f
M
PPT (M
a
x
im
um
Powe
r P
o
i
n
t Trac
ke
rs)
.
P
V
sy
stem
with M
PPT c
ont
roll
er
has
been
s
h
o
w
n
in
fig
u
re
3
.
Figure
2. (a
) PV c
h
aracteristi
c at constant
i
n
sol
a
t
i
o
n
an
d
di
ffe
rent
t
e
m
p
era
t
ures
[
5
]
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
IJEC
E V
o
l
.
6, No
. 2, A
p
ri
l
20
16
:
56
7 – 5
8
2
57
0
Figure
2. (b) IV c
h
aracteristi
c at constant
i
n
sol
a
t
i
o
n
an
d
di
ffe
rent
t
e
m
p
era
t
ures
[
5
]
Fi
gu
re 3.
B
l
oc
k di
ag
ram
of M
PPT
t
ech
ni
q
u
es [1
0]
3.
CLAS
SIFI
C
A
T
ION OF MP
PT
TECH
N
I
Q
UES
The classificat
ion
of comm
only use
d
MPPT techni
que
in th
e PV system
is sh
own in figu
re
4
.
Th
e
fo
llowing
secti
o
n will briefly
rev
i
ewed th
e
main
MPPT tech
in
iqu
e
s.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
A Review on
P
hot
o V
o
ltaic M
PPT Al
gorithms
(
Sar
ava
n
Sel
v
an)
57
1
Fi
gu
re
4.
C
l
assi
fi
cat
i
on
of
co
m
m
onl
y
used
M
PPT Tec
h
ni
q
u
e
3.
1
Offline Technique
The
of
fl
i
n
e t
echni
que i
s
c
o
m
m
onl
y
cal
l
e
d as i
ndi
rect
t
e
chni
que
si
nce
t
h
i
s
al
go
ri
t
h
m
i
s
wo
rke
d
i
n
o
f
flin
e i.e.
n
o
t
o
n
th
e
real time. In
th
is tech
n
i
q
u
e
, th
er
e is a n
ecessity o
f
prio
r
requ
iremen
t o
f
p
a
rticu
l
ar
PV
p
a
n
e
l
d
a
ta su
ch
as th
e m
a
th
ematical
m
o
d
e
lin
g, I-V, P-
V c
u
rve, etc. T
h
e
basic in
di
rect
t
echni
que
s o
f
M
PPT
are o
p
en ci
rc
ui
t
vol
t
a
ge an
d Sh
ort
ci
rcui
t
cur
r
ent
m
e
t
hod [5]
.
I
n
b
o
t
h
t
h
e
m
e
t
hods, a
DC
/
D
C
co
nve
r
t
er wi
t
h
th
e d
r
iv
er circu
it is co
n
t
ro
lled
b
y
th
e
m
i
cro
c
o
n
t
ro
ller or
DSP o
p
e
rates eith
er in
Bu
ck
/Bo
o
s
t m
o
d
e
is req
u
i
red.
The
dut
y
cy
cl
e of t
h
e s
w
i
t
c
hi
ng c
o
nv
ert
e
r c
a
n b
e
va
ri
ed
b
a
sed
on t
h
e c
o
m
put
at
i
on of
t
h
e o
p
e
n
ci
rc
ui
t
vol
t
a
g
e
or
sh
ort
ci
rcui
t
cur
r
ent
t
o
t
r
ac
k
t
h
e m
a
xim
u
m
po
we
r
poi
nt
(
M
PP).
3.
1.
1
Open Circuit Vol
t
age
Technique
In t
h
i
s
t
ech
ni
q
u
e, t
h
e val
u
e o
f
Vm
pp un
der
di
ffe
re
n
t
so
lar in
so
lation
and
te
m
p
eratu
r
e is calcu
lated
app
r
oxi
m
a
t
e
ly
by
t
h
e e
q
uat
i
o
n:
V
m
p
p
=
K
1
V
o
c
E
q
n
.
3
.
1
Wh
ere
Vo
c is t
h
e op
en
circu
it v
o
ltage,
K1
is
th
e co
e
ffi
ci
ent
val
u
e ran
g
es fr
om
0.71
t
o
0.
9 depe
n
d
i
n
g
up
o
n
t
h
e
c
h
ar
act
eri
s
t
i
c
s of
t
h
e
panel
.
T
h
e
val
u
e
of
Vm
pp
i
s
c
o
m
put
ed
by
m
easuri
n
g t
h
e
val
u
e
o
f
V
o
c
peri
odi
cal
l
y
.
3.
1.
2
Shor
t
Circuit Current
Technique
Thi
s
t
ech
ni
q
u
e
i
s
al
so sim
i
l
a
r t
o
t
h
e pre
v
i
o
u
s
i
ndi
rect
m
e
t
hod i
n
st
ead
of
v
o
l
t
a
ge co
nt
r
o
l
l
e
d he
re t
h
e
com
put
at
i
on i
s
based
o
n
t
h
e
v
a
l
u
e o
f
sh
ort
ci
rcui
t
cu
rre
nt
Is
c of P
V
panel
.
The
peak
val
u
e of c
u
r
r
ent
Im
pp i
s
com
put
ed
by
t
h
e
fol
l
o
wi
n
g
e
quat
i
o
n a
s
:
I
m
p
p
=
K
2
I
s
c
E
q
n
.
3
.
2
Whe
r
e K2 is the coe
fficient
valu
e ra
n
g
es f
r
om
0.7
3
t
o
0
.
9
5
de
pe
ndi
ng
on t
h
e cel
l
m
a
t
e
ri
al
and
charact
e
r
i
s
t
i
c
s of t
h
e PV
pa
ne
l
.
B
y
co
m
put
i
n
g t
h
e
val
u
es
of
Im
pp, at
di
ffe
r
e
nt
sam
p
l
e
d va
l
u
es o
f
Isc
,
t
h
e
dut
y
cycle of the
DC/DC conve
rter is increased or dec
r
ease
d
so
th
at th
e ou
tpu
t
cu
rren
t
b
e
co
mes equ
a
l to
Imp
p
.Th
e
i
m
p
l
e
m
en
tatio
n
o
f
t
h
is algo
ri
th
m
resu
lts reviewed
i
n
th
e lit
eratu
r
e repo
rts
th
at regard
ing
th
e co
st
wise i
s
v
e
ry
effect
i
v
e
b
u
t
t
h
e
per
f
o
r
m
a
nce wi
se i
s
n
o
t
go
o
d
du
ri
n
g
d
i
ffere
nt
i
r
radi
a
n
ce
of
su
n a
n
d
di
ffe
re
nt
o
p
e
rat
i
n
g
te
m
p
erature
of
the pa
nel.
3.
2
Online Techni
que
The popula
r
online techniques use
d
directl
y
for
t
h
e m
a
xi
m
u
m
powe
r
p
o
i
n
t
are Pe
rt
u
r
b an
d O
b
se
rve
Techn
i
qu
e (P&O) an
d
In
cremen
tal co
n
d
u
c
tan
ce Techn
i
que (IN
C
)
[1-4
].
In
th
e d
i
rect te
ch
n
i
q
u
e
s, th
ere will b
e
an o
n
l
i
n
e m
easurem
ent
of
vol
t
a
ge an
d m
easurem
ent
of t
h
e
panel
peri
odi
c
a
l
l
y
for com
p
u
t
i
ng t
h
e
dut
y
c
y
cl
e of
t
h
e co
n
v
ert
e
r t
o
t
r
ac
k t
h
e m
a
xi
m
u
m
powe
r
poi
nt
M
PPT
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
IJEC
E V
o
l
.
6, No
. 2, A
p
ri
l
20
16
:
56
7 – 5
8
2
57
2
3.
2.
1
P&O MPPT Algorithm
Th
is algo
rith
m
is an
iterativ
e tech
n
i
qu
e an
d
v
e
ry sim
p
le o
n
e. It m
easu
r
es th
e p
a
n
e
l op
erat
in
g
v
o
ltag
e
and curre
nt
pe
riodically and
calcula
tes
th
e in
stan
tan
e
ou
s p
o
wer p
(
n
)
.
Th
is
in
stan
tan
e
ou
s po
wer
co
mp
ares
wi
t
h
t
h
e
p
r
e
v
i
o
us
out
put
p
o
w
e
r P
(
n
)
-
P
(
n
-
1
)
,
t
h
en
t
h
e
o
p
era
t
i
ng
vol
t
a
ge
X
(
n+1
)
i
s
det
e
rm
i
n
ed a
n
d c
h
an
g
e
d
by
chan
gi
n
g
t
h
e
dut
y
rat
i
o
o
f
t
h
e co
nve
rt
er
X(
n+c)
or
X(
n-c
)
. T
h
e si
g
n
of cha
n
ge o
f
out
p
u
t
p
o
we
r
i
s
al
so
o
b
s
erv
e
d
to
track
th
e MPP. If th
e ou
tpu
t
p
o
wer in
cr
eases b
y
in
creasin
g
th
e op
eratin
g
vo
ltag
e
, th
en
the
o
p
e
rating
v
o
ltag
e
is
furth
e
r
pertu
r
b
e
d
in th
e sam
e
d
i
r
ectio
n
u
n
til it reaches th
e
p
o
i
n
t
of MPP
o
r
dp
/dv=0
.
If
t
h
e
o
u
t
put
p
o
w
e
r decrease
s
by
i
n
crea
si
n
g
t
h
e
ope
rat
i
n
g vo
ltag
e
, i.e th
e op
eratin
g
po
in
t is i
n
th
e
n
e
g
a
tiv
e
slo
p
e
regi
on
of t
h
e
PV cu
r
v
e. T
h
e
n
t
h
e o
p
er
at
i
n
g v
o
l
t
a
ge i
s
pe
rt
ur
be
d i
n
t
h
e
reve
rse di
rect
i
on t
o
t
r
a
c
k t
h
e
M
PP.
Th
e
flow ch
art
o
f
th
e
P&O algo
rith
m
is sho
w
n
in th
e
figu
re
5
.
Fi
gu
re
5.
Fl
o
w
cha
r
t
o
f
P
&
O
al
go
ri
t
h
m
[12]
The m
a
i
n
advant
age o
f
t
h
i
s
t
echni
que i
s
ve
r
y
sim
p
l
e
and easi
l
y
im
pl
em
ent
e
d. B
u
t
t
h
e d
i
sadva
nt
age
is th
e op
erating
po
in
t is
h
i
gh
ly o
s
cillated
aroun
d
t
h
e M
PP po
in
t and
n
o
t
fix
e
d
o
n
t
h
e ex
act MPP. Th
e
literatu
re rev
i
ew
rev
eals th
at
if we in
crease
th
e step
size
of th
e algo
rith
m
,
th
e o
s
cillation
s
aroun
d th
e
MPP
will b
e
m
o
re an
d d
y
n
a
m
i
c. If we redu
ce th
e
step
size,
t
h
e co
nv
erg
e
n
ce speed
will b
e
v
e
ry less and
canno
t ab
le
to
track
t
h
e M
PP at
v
a
ri
ou
s at
m
o
sp
h
e
ric con
d
ition
s
. Sev
e
ral research
ers i
n
the rev
i
ew su
gg
ested
o
r
mo
d
i
fied
th
e P&O al
g
o
ri
th
m
to
h
a
v
e
b
e
tter effi
ciency
com
p
are to t
h
e
conve
ntional.
3.
2.
2
Incremen
tal Conduc
tance Algorithm
(I
NC)
Th
is is a m
o
st po
pu
lar MPPT algo
rith
m
an
d wi
del
y
use
d
.
The
di
sa
d
v
a
n
t
a
ges
o
f
t
h
e
P&O
M
PPT
alg
o
rith
m
is o
v
e
rco
m
e an
d
eli
m
in
ated
b
y
t
h
is INC techn
i
q
u
e
bu
t it is
m
o
re co
m
p
lex
and
very
d
i
ffi
cu
lt to
im
ple
m
ent. The theory
of the
increm
ent
a
l
con
d
u
ct
ance i
s
t
o
det
e
rm
i
n
e the va
ri
at
i
on
di
rect
i
on
of t
h
e
out
pu
t
t
e
rm
i
n
al
vol
t
a
ge of t
h
e P
V
m
odul
es by
m
easuri
ng a
nd c
o
m
p
ari
n
g
t
h
e i
n
crem
ent
a
l
cond
uct
a
n
ce and
instantane
ous conductance
of
PV m
o
du
les. If th
e v
a
l
u
e
of in
crem
ental conductance
a
n
d th
e in
stan
tan
e
ou
s
conductance a
r
e equal
,
then it represents the ope
rating poi
nt reaches
the MPP
m
a
xim
u
m
power
poi
nt.
Com
p
are to the offline techniques
,
th
e onli
ne techniques l
i
ke increm
enta
l conducta
nce
(INC) algorit
h
m
s
ar
e
adva
nt
age
o
us
un
de
r rapi
dl
y
chan
gi
n
g
at
m
o
sph
e
ri
c co
ndi
t
i
ons
but
i
t
i
n
v
o
l
v
es c
o
m
p
l
e
x cal
cul
a
t
i
on w
h
i
c
h
increases
the
hardware
re
quire
m
ent and c
o
st.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
A Review on
P
hot
o V
o
ltaic M
PPT Al
gorithms
(
Sar
ava
n
Sel
v
an)
57
3
The
basic c
onc
ept of
Inc
r
em
e
n
tal conductance on a PV
curv
e is sh
own
in f
i
gu
r
e
6. Th
e
slo
p
e
of
the
P-V c
u
rve is zero at the MPP, increas
i
n
g o
n
t
h
e l
e
ft
of t
h
e M
PP and
decre
a
si
ng
on t
h
e R
i
ght
si
de
of t
h
e
M
PP.
Th
e
b
a
sic eq
uatio
n
s
o
f
th
is m
e
th
od
are as
fo
llo
ws.
Fi
gu
re
6.
C
o
nc
ept
o
f
Inc
r
em
ent
a
l
co
nd
uct
a
n
ce al
go
ri
t
h
m
dP/
d
V
=
0
at
MPP
d
P
/d
V>0
left o
f
MPP
dP/
d
V
<
0
ri
ght
of
MPP
dP/
d
V
=
d(
V
I
)
/
d(
V)
= I +
V*
d
I
/
d
V
E
q
n
.
3
.
3
Th
e
d
P
/dV is
d
e
fi
n
e
d
as Max
i
m
u
m
p
o
w
er
p
o
i
n
t
id
en
tifier factor. By
u
tilizin
g
th
is
fact
o
r
, th
e
INC
m
e
thod is propose
d to effecti
v
ely track the
MPP of P
V
m
o
dule. T
h
e followi
ng
defi
nitions a
r
e considered to
track t
h
e MPP.
∆
I/
∆
V =
-I/
V
at M
PP,
∆
V
n
=
0
E
q
n
.
3
.
4
∆
I/
∆
V >
-I/
V
left of
M
P
P
,
∆
Vn=
+
δ
E
q
n
.
3
.
5
∆
I/
∆
V <
-I/
V
rig
h
t o
f
M
P
P,
∆
Vn=
-
δ
E
q
n
.
3
.
6
Whe
r
e
∆
Vn
is th
e ch
an
g
e
in
t
h
e op
erating
vo
ltag
e
of n
t
h
iteratio
n
an
d
δ
s
i
gn indicates the increa
se
or de
crease the
step size of the conver
t
e
r
.
C
onsi
d
er t
h
e
nt
h
i
t
e
rat
i
on of t
h
e al
gori
t
h
m
as
a refere
nce, a
n
d t
h
e
n
n+1 i
t
e
rat
i
o
n
p
r
oces
s can
be d
e
t
e
rm
i
n
ed by
u
s
i
ng t
h
e a
b
ove
equat
i
o
ns
. The
M
PPT re
gul
at
es t
h
e P
W
M
c
ont
rol
sig
n
a
l of th
e DC/DC p
o
wer co
nv
erter un
til t
h
e con
d
ition
:
(d
I/
d
V
) + (I/V)
= 0
is satisfied
. Th
e Flow chart o
f
i
n
crem
ent
a
l
cond
uct
a
nce
M
P
PT al
g
o
ri
t
h
m
i
s
sh
ow
n i
n
fi
g
u
re
7.
Thi
s
t
e
chni
que
gi
ves
go
o
d
re
sul
t
s
d
u
ri
ng
rap
i
d
l
y ch
ang
i
n
g
en
v
i
ron
m
en
t co
n
d
ition
s
wi
th
m
i
n
i
m
a
l o
s
cillatio
n
s
. Bu
t t
h
e co
m
p
lex
com
p
u
t
atio
n
p
r
o
c
ed
ure
o
f
th
is algorithm
mak
e
s th
e i
m
p
l
e
m
en
tatio
n
v
e
ry d
i
ffic
ult
and converge
nce towa
rds
the
MPP
is not
acc
urate.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
IJEC
E V
o
l
.
6, No
. 2, A
p
ri
l
20
16
:
56
7 – 5
8
2
57
4
Fi
gu
re 7.
Fl
o
w
chart
of
I
n
cr
e
m
ental conductan
ce algorithm [4]
3.
2.
3
Slide Mode
Control
Th
is con
t
r
o
l tech
n
i
q
u
e
is u
s
ed
f
o
r
no
n
lin
ear
syste
m
s. I
t
p
r
o
v
i
d
e
s con
t
ro
l o
f
pow
er
conver
t
er
wh
ich
t
r
acks t
h
e M
P
P un
de
r t
h
e con
d
i
t
i
on
of
va
ry
i
ng i
r
radi
a
n
c
e
. Sl
i
d
e m
ode cont
r
o
l
al
go
ri
t
h
m
s
i
s
based on t
h
e
on/
of
f c
ont
rol
l
i
ng t
h
e
po
wer
swi
t
c
h
o
f
t
h
e
Dc-
D
c c
o
nve
rt
er
whi
c
h c
o
nt
i
n
u
o
u
sl
y
t
r
a
c
k t
h
e
M
PP,
so t
h
e
efficien
cy
o
f
this alg
o
rith
m
is v
e
ry
h
i
gh
. Th
e MPPT sp
eed
will b
e
faster
wh
en
i
n
creasing
t
h
e switch
i
ng of the
con
v
e
r
t
e
r b
u
t
t
h
e p
o
we
r o
u
t
p
ut
and
vol
t
a
ge
out
put
fl
uct
u
at
i
on i
n
cr
eases.
The sl
i
d
i
n
g m
o
de co
nt
r
o
l
con
s
i
s
t
s
of
sliding s
u
rface
and c
ont
rol la
w desi
gn. The
sliding s
u
rf
ace
is define
d base
d on Increm
ental Conductanc
e (IC)
MPPT algorithm
[9]. From
the Incr
em
ental conductance
algorithm
.
(
d
I
/
d
V
)
+
(
I
/
V
)
=
0
E
q
n
3
.
7
The st
at
e e
q
uat
i
on
s f
o
r t
h
e
B
u
ck
-B
o
o
st
c
o
n
v
ert
e
r
i
s
gi
ve
n
by
L
V
D
L
V
D
dt
dI
o
p
L
)
1
(
.
E
q
n
3
.
8
Wh
ere, IL is the in
du
ctor cu
rren
t
,
Vp is th
e PV
p
a
n
e
l
vo
ltage,
D is t
h
e
d
u
t
y ratio
of th
e swit
ch
,
Vo
is t
h
e
ou
pu
t
v
o
ltage.
The i
nve
rsi
o
n
of
t
h
e e
q
uat
i
o
n
(
3
.
7
) i
s
gi
ven
by
-
d
V
p
/
d
I
p
=
V
p
/
I
p
E
q
n
3
.
9
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
A Review on
P
hot
o V
o
ltaic M
PPT Al
gorithms
(
Sar
ava
n
Sel
v
an)
57
5
In
th
e equ
a
tio
n (3
.9), th
e
p
a
rameter -d
Vp
/dIp
is called
as in
stan
tan
e
ou
s resistan
ce (Rp)
an
d
Vp
/Ip
i
s
called as inc
r
e
m
ental resistance (rp). s
o
t
h
e equation no.3.9
ca
n reform
ulated
as
δ
=
R
p
-
r
p
E
q
n
3
.
1
0
The differe
n
ce
of these resist
ance value is
define
d the sliding s
u
rface of MPPT.
Whe
n
e
v
er
δ
val
u
e
becom
e
s zero whi
c
h i
ndi
cat
e
s
t
h
e achi
e
vem
e
nt
of m
a
xim
u
m
power
poi
nt
(M
PP). T
h
e c
ont
rol
l
a
w i
n
p
u
t
[1
6]
fo
r M
P
P
T
ca
n
be
defi
ned
by
t
h
e
fol
l
o
wi
n
g
e
quat
i
o
n.
X
(
t
)
=
X
e
q
(
t
)
+
X
n
(
t
)
E
q
n
3
.
1
1
W
h
er
e
X
e
q
(
t)
is d
e
f
i
n
e
d as t
h
e system
b
e
hav
i
ou
r
on
slid
i
n
g sur
f
ace.
X
n
(
t
)
is
k
now
n as no
n lin
ear
swi
t
c
hi
n
g
i
n
p
u
t
s. Xe
q(t
)
i
s
o
b
t
a
i
n
ed
f
r
om
i
nva
ri
ant
c
o
ndi
t
i
on a
n
d i
t
i
s
gi
ven
as
(
δ
= 0,
d
δ
=
0)
i
s
bi
e
qui
val
e
nt
t
o
(X=
Xe
q)
Eq
n
3.
12
Th
e
d
e
ri
v
a
tiv
e
o
f
equ
a
tion
(3
.1
0)
with
resp
ect to
tim
e can
b
e
written
as
d
δ
=d
R/d
t
- dr/dt, th
en
Mu
ltip
ly b
o
t
h
sid
e
s
b
y
dIp
/
d
t
, b
e
co
m
e
s
d
δ
=
(
dR
/
d
I
p
-
d
r
/
I
p)
.
d
I
p/
dt
d
δ
=
ω
dI
L/
d
t
w
h
e
r
e
I
L
=
K
.
I
p
E
q
n
3
.
1
3
whe
r
e k
i
s
p
r
o
p
o
r
t
i
o
nal
co
nst
a
nt
.
By substituting equation (3.8
)
in equation
(3.13), the tim
e derivativ
e
of sliding surface is
obtaine
d a
s
:
L
V
t
x
L
V
t
x
d
o
p
)).
(
1
(
).
(
Eq
n
3.
14
Co
n
s
i
d
er
i
n
g equ
a
tio
n 3.14
and
eq
u
a
tion
3
.
12
, t
h
e eq
u
i
v
a
len
t
con
t
ro
l input is ob
tain
ed as
Xeq
(
t
)
=
V
o
/
(
V
o
+V
p)
Eq
n
3.
15
Now
Xn
(t) is ch
oo
sen
so
t
h
at
th
e Lyapun
ov
stab
ility criteri
a (d
δ
.
δ
<
0)
is
m
e
t
T
h
e
cho
o
s
en
Xn
(
t
) a
s
)
1
(
1
M
V
V
V
t
X
p
o
o
n
E
q
n
3
.
1
6
Wh
ere M is t
h
e co
n
t
ro
l sign
al wh
ich
is calcu
l
ated
throu
g
h
Lyap
uno
v stab
ility crite
ria. Th
en
add
i
n
g
t
h
e
equat
i
o
n (
3
.
1
5
)
&(
3.
1
6
)
X
(
t
)
=
1
/
(
1
+
M
)
E
q
n
3
.
1
7
B
y
consi
d
eri
n
g
t
h
e
ope
rat
i
n
g
poi
nt
o
f
sy
st
e
m
i
s
‘a’ whi
c
h i
s
s
h
o
w
n i
n
f
i
gu
re n
o
.
si
nce
t
h
e
gra
d
i
e
nt
i
s
negat
i
v
e
,
m
ovi
ng t
h
e o
p
e
r
at
i
ng p
o
i
n
t
t
o
t
h
e ri
ght
si
de c
a
uses i
n
c
r
easi
n
g i
n
t
h
e c
u
rre
n
t
of P
V
ar
ray
,
whi
c
h
resu
lts in d
e
creasin
g
of Rp
an
d
increa
sing of
rp, t
h
ere
f
ore
,
(
∂
Rp
/
∂
Ip<0
,
(
∂
rp/
∂
I
p
>
0
).
Al
so,
m
ovi
ng
t
h
e
ope
rat
i
n
g
poi
nt
t
o
t
h
e
l
e
ft
si
de
causes
dec
r
ea
si
ng
i
n
t
h
e c
u
r
r
e
nt
o
f
PV
ar
ra
y
,
w
h
i
c
h
res
u
l
t
s
i
n
i
n
creasi
n
g
of
R
p
and dec
r
easing of rp, the
r
efore, (
∂
Rp
/
∂
Ip
>0
,
(
∂
rp/
∂
Ip<
0
). for
positive
sliding surface (
δ
>0
)
;
p
p
o
p
p
o
p
dI
dV
V
I
V
V
V
)
.(
)
1
(
E
q
n
3
.
1
8
whe
n
(
δ
<0
)
,
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
IJEC
E V
o
l
.
6, No
. 2, A
p
ri
l
20
16
:
56
7 – 5
8
2
57
6
p
p
o
p
p
o
p
dI
dV
V
I
V
V
V
)
.(
)
1
(
E
q
n
3
.
1
9
From
t
h
e e
quat
i
on
(
3
.
1
8
)
&
(
3
.1
9)
, t
h
e
co
nt
r
o
l
l
a
w M
ca
n
be
ch
oo
sen
as
p
p
o
p
p
dI
dV
V
I
V
M
)
.(
)
1
(
E
q
n
3
.
2
0
Sub
s
titu
tin
g equ
a
tio
n (3
.20
)
i
n
eq
u
a
tion
(3
.17
)
, th
e con
t
ro
l
in
pu
t is
o
b
t
ained
as
1
)
1
(
)
.(
1
)
(
p
p
o
p
p
dI
dV
V
I
V
t
X
Eq
n
3.
21
The
duty cycle m
u
st be lie in
0<D<
1,
D =
)
(
1
,
1
1
)
(
0
),
(
0
)
(
,
0
t
X
t
X
t
X
t
X
3.
3
Intellig
ent Technique
In
tellig
en
t MPPT con
t
ro
llers are v
e
ry robu
st th
an
conv
en
ti
o
n
a
l
n
o
n
lin
ear co
n
t
ro
llers an
d it is ab
le to
effectively improve the dy
na
m
i
c response
and stea
dy
st
at
e perf
orm
a
nc
e of t
h
e P
V
sy
st
em
s. The fol
l
owi
n
g
sectio
n
is
b
e
i
n
g
rev
i
ewed b
y
th
e m
a
in
In
tellig
en
t al
g
o
rith
ms.
3.
3.
1
F
u
zzy
Lo
g
i
c
C
o
n
t
ro
l
The Fuzzy logic controller us
es the fuzzy logics to
m
a
ke the deci
si
o
n
s a
nd t
o
c
ont
r
o
l
t
h
e o
u
t
p
ut
of
t
h
e co
nt
r
o
l
l
e
r.
The
m
a
i
n
com
ponent
s i
n
f
u
zzy
l
o
gi
c ba
s
e
d M
P
P
T
c
o
n
t
rol
l
e
r a
r
e f
u
z
z
i
f
i
cat
i
on,
r
u
l
e
-bas
e
,
infere
nce and defuzzification
as s
h
o
w
n i
n
fi
gu
re
8.
Fi
gu
re 8.
F
u
zz
y
l
ogi
c bl
oc
k d
i
agram
Th
ere are two
i
n
pu
ts t
o
th
e con
t
ro
lle
r – error e(k) a
n
d c
h
ange in error
Δ
e
(
k)
. T
h
e F
u
zzi
fi
cat
i
on
bl
oc
k
con
v
e
r
t
s
t
h
e cri
s
p i
n
p
u
t
s
t
o
fu
zzy
i
nput
s. T
h
e rul
e
s are fo
r
m
ed i
n
rul
e
ba
se and are ap
pl
i
e
d i
n
i
n
fere
nc
e bl
ock
.
The defuzzific
a
tion
c
o
nve
r
ts the
fuzzy
o
u
t
p
ut
t
o
t
h
e cri
s
p
out
put
.
T
h
e f
u
zzy
i
n
fere
nce i
s
carri
e
d
out
b
y
usi
n
g
M
a
m
d
ani
’
s m
e
t
h
o
d
[1
0]
, a
n
d
t
h
e
def
u
zzi
fi
ca
t
i
on
uses
t
h
e
c
e
nt
re
o
f
gra
v
i
t
y
t
o
c
o
m
put
e t
h
e
out
p
u
t
o
f
t
h
i
s
FLC
whic
h is t
h
e c
h
ange
in
duty cycle.
The i
n
puts t
o
t
h
e
Fuzzy c
o
ntroller a
r
e c
h
a
n
ge in
PV array
Power (
Δ
P
P
V
)
an
d c
h
a
nge
i
n
PV
ar
ray
current (
Δ
IPV) co
rresp
ond
ing to
th
e two
sam
p
l
i
n
g
tim
e
in
st
ant
s
. T
h
e t
w
o i
n
put
s a
r
e
pr
ocesse
d by
t
h
e
Fuzzy
co
n
t
ro
ller an
d
th
e ou
tpu
t
of th
e Fu
zzy con
t
ro
ller is th
e in
crem
en
tal referen
ce curren
t
(
Δ
Iref). Th
is outp
u
t
is
gi
ve
n t
o
t
h
e
D
c
-Dc
p
o
w
er
co
nve
rt
er.
T
h
e
fi
rst
i
n
put
va
ri
abl
e
(
Δ
P
p
v)
f
o
r
t
h
e
fuzzy
l
ogi
c co
nt
r
o
l
l
e
r i
s
di
vi
d
e
d
in
to
sev
e
n
Fuzzy sets: PB
(Positiv
e Big
)
, PM (P
o
s
itiv
e Med
i
u
m
), PS (Po
s
itiv
e Sm
all), ZZ (Zero), NS
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