noitcetorPmetsyS lacirtcelE ni
rPeto
itc no
.
.
. ( )
:
:
rPeto
itcno
-
-
132
5
6
4
Auxiliary Trip Relay
Alarm System
IPCT
IPVTVT
CT
++
--
110V DC Supply bus wire50V DC Supply bus wire
Main Protective Relay
AC Contact
Timer
Trip Coil
RYB
yticilpmiS esnopser kciuQ
ytilibaileR
ytivitceleS
ytivitisneS
ymonocE
Operating timeOf Relay
Operating time ofauxiliary Relay
closing time ofCircuit breaker
0 s
time[s]
Total operating time of protection circuit
Speed
:
yticilpmiS
ytilibaileR
ytivitisneS
4.1 > sK oI / nim fI = sK
- -
-
-.
ytivitceleS
: . - . -. -. -
2F
1BC1F
4BC 3BC
2BC
B AX
X
X
X
X
X
X X
1G
2G
C
scimonocE
.
:
-
-.
:
.
( )
.
: : .
.... .
:
syaler evitcetorP
(. ) - : (. ) -
. - : . - . - - ..... -
.
(sBCM ,sesuF) -(syaleR .cetorP) -
- - -
syaleR tnerruC
)RCO( syaleR tnerruC revO
syaleR laitnerefeD
syaleR ecnalabnU
syaleR tnerruC
S/P CD sTC sTV -. -
syaleR tnerruC
K
L
k
l
+-
ab
a
b
c
d
e
f
I1
2
+ 2
1a
b
c
d
f12
I
a bc
f
e
1
2
a
b
c
d
I
reppotS
=
nI X
.ceS
.ceS
nI X
.ceS
nI X
nI X
.ceS
RST
BK
L
Nk
l
TL4
2
1
:
:
Kl
NTi+Si+Ri=0i3
k
TI SI RI
>0IT
L
RU
+
Sig
Voltage Relays
UVR
OVR
If
0 0.5 1
Uph
U
= % of coil length
Deferential RelaysWhy?
L K
3
LK
kl lk
1i2i2i -1i=di
2i 1i
+
.giS
2 1
2I 1I
syaleR laitnerefeD
( )
K L
3
LK
kl lk
1i2i
2i -1i=di
2i 1i
+
.giS
2 1
2I 1I
syaleR laitnerefeD
: 2i 1i = di & 2i = 1i , 2I = 1I
0 = di neht 2i = 1i fI
: 0 2i 1i = di & 2i 1i , 2I 1I
KL
3
KL
kl lk
i2i1
id=i1- i2
i1 i2
+
Sig.
1 2
I1 I2
Deferential Relays
)10% - 40% ( .
Actually i1 i2 :- Vector group of protected Tr.- n1 n2- Outside S/C.- Prim. Curr. of Protected Tr. Sec. Curr.- Protected Tr. Have ON Load Tap Changer.
Relay (3) isn't instantaneous relay
i
CT2
CT1
IPVT1
IPVT2
MT
CT1 CT2
CT3
IPVT2
IPVT3
IPVT1
U1 U2
U3
YY
d
Yy0
Yd5
Yd5
Yy0
Yd5
I1 I2
i1
i1i3 i2
i3
i2
n=5 1
0I
iCTs Characteristics
5In
Point ofsaturation
10In
n=102
n=20 3
20In
I
Unbalance Current
LKL K
kl lk
2i1i
0=2i -1i = di
2i 1i
1
5
3
2
4
+
)2i +1i( 2/1=si
lioC laitnereffiDlioC gnizilibatS
A
idl
is
iop
iop min
i2op = i2op min + K2s i2s
Ks = tg Ks
MMF I2
iS = 0
F in spring
Unbalance current
Operating Characteristics
LKL K
kl lk
2i1i
2i -1i = i2
2i 1i
1
5
3
2
4
+
)2i +1i( =0
2I 1I
)2i+1i(2/1=si
2i - 1i =di
ST
dT
2i 1i
12I 1I
2
4 3
yaleR ecnalaB lacirtcele fo lapicnirP
5+
gnisolC
gninepO
Moment I iop = iop min + Ks isKs = tg KS & = f(N2 of TS or R)
Not applicablecharacteristics
Unbalance current
Operating Characteristics
Non linear resistance or EMFIn stabilizing circuit
A
B
a b
idl
In xIn is
iop
iop min
I1 I2
I>
i1 i2
i1 i2
id = i1 i2N2
N2
Ns
Ns
NdNi i2
i2
d
s
i
s
Protec. Element
Magnetic Balance Relay
Directional Protection Relays
0.2 s0.4 s0.6 s
0.8 s
0.2 s0.4 s0.6 sIf
If
If If
If
Supply
0.2 s0.4 s0.8 s
Why?
: .
.
soC I UK = P0 09
ro fi 0 > P072 0
0 < P eslE
14
i3I ri
ui
2u
ru
.
mM - ) + r(soC ri rU K = rM rM:
. r . . K ... . . ) mM
) + r( no sdnepeD 0< ro 0> ro 0 = rMmM ) + r(soC ri rU K etarepO eb oT
14
( )
3
iI ri
ui
2
u
ru
14
3iir I
iu
2u
ur
M = k iusini I u U
i
ui u
I
u Iu
U
i = u M = k1 IU sin(u - )u = 90 - M = k1 IU cos( + )If P = IU cos ( + ) M = k1 P
P = IU cos ( + ) + (U/2)2 + (I/2)2 - (U/2)2 + (I/2)2P = (U/2)2 + (UI cos( + ))/2 + (I/2)2 (U/2)2 - (U/2)2 cos( + ))/2 + (I/2)2
P = U/2 + I/2 2 - U/2 - I/2 2
U
I
|U + I|2 |U - I|2
U|U + I| |U - I|
U
|U + I| |U - I|
:
R
ii - ui ii + ui
ii
uiU
ri
syaleR ecnalaB lacirtcelE
2rT 1rT
Riu + ii iu - ii
ii
iuU
ir
R
ii - ui ii + ui
ii
ui
U
ri
)ii - ui( CDI )ii + ui( CDI
| ii - ui | - | ii + ui | = ri
R
iu - ii
| iu + ii | - | iu - ii |
ii
iu
iu + ii| iu + ii | - | iu - ii |
iu
ii
Lagging iu by
0 , Lagging
:
+ = 90 (VAR) Q - relays
Depending on its construction these relays can be divided into :- Induction relays,- Electro dynamic Relays,- Electrical Balance Relays.
+ = 30 - 180 (VA) S - relays
+ = 0 (W) P - relays
+ = 180 Reverse Power relays
: ( 081 ,09 ,08 ,06 ,54 ,03 ,0) ( ) -
( 09 ro 0) ( ) -
-
-
) A 5 ro 1 ) ( V 3011 rO 011( -
(P - j Q )
jQ
P
jQ
P
Operate
NotOperateN
ever
Ope
rat e
Alw
ays O
pera
te
=45o
=0o
Error Boundary when U=100% Un
Error Boundary when U=K1% Un K1
A Theoretical setting valueG Nominal value relay.
Error Boundary when U=100% UnError Boundary when U=K1% Un K1
= const.
Operate
Not Operate
Voltage U
Iop
OperatingCurrent
Operating Characteristics of Directional relay as Iop = f(U)
030
6090120
150
180
150
6090120
30
TheoreticalCharacteristic
ReferencePhase
Direction ofnon reference
value
Always Operate
Never Operate
Error Boundary when 100% Reference value Error Boundary when K1% reference value
Oper. Char. of Direc. relay in polar system = 30
Operating Characteristics of Directional relay as Uop = f(I)
1 2 3
Operate
Not Operate
I
Uop
Time Characteristics of Directional relay
P
t (s)
Nom.power
Setpoint
Top.
P
ts or min.
OperatingTime
Time Characteristics of Directional relay
Distance RelaysLTL >> No of TL Supplies >> Complex form Of TL >>
Geographical & Natural Conditions become more Difficult
Probability of Faults becomes more & more
request the protective relays to have a high speed to eliminate the faults as quick as possible.
0.20.40.60.811.2 1.210.80.60.40.2
Solution: top
G GA B C D
F1 2 3 4 5 6
UfUf
Distance Relays
UopUop
Old Criteria : top U Disadvantages: - U = f(ZL, If) top>> as If >>- Zfault >> so U >> top >>
LiLu
U
i
u = cu1 USC i = ci1 ISC Fu = cu2 u2 Fi = ci2 i2
Fu Lu= Fi Li cu u2 = ci i2 (u/i)2 = ci/cu = k12
u/I = cu1 USC/ci1 ISC= c Z Z = k1/c = K
SCK
Z0 = K
Z = k1/c = K R2 + X2 = K
Rarc
Ui
ki
u ki 2 = i2 z = u/i z k 2 = 1
Its a vector has ohm character
If the angle between k & z is then : z2 2zk cos + k2 = 1
z2 2zk cos + k2 = 1
k sc
Z = Kz
Z2 2ZkK cos + (kK)2 = K2
kKsc
K
cs K
K
Z 1 = k roF2K = 2K + soc KZ2 2
yaleR HOM
1 0=K
iik-U
+|i| |ik-u|
.giS
New Criteria : top (U, 1/If) Distance Relays
top = K U/If = K Zline
Zline = Z1 * L & U = I * Z1 * L
These Relays called : Impedance or Distance Relays
Impedance oflength unit
DistanceR - FVoltage where the
Relay build in
+ +
- +
-
-
F M D S
T
)s( t
)mK( L
4t3t
1t2t3L 2L 1L
syaleR ecnatsiD
>> rtL & >> rtU
>> ecnatsiD evitcetorP
poZ L/OZ ro .dnoC .ronZ >> rtP
tesZ < enilZ snoitidnoC gnitarepO
.
Distance Relays
.
B
A
B
A
jX
R
ZL between A & B
Rarc + Rf.pointAt ideal cases relay
Should operate, if themeasured impedance
Less than A-B & ss : S/C angle of faulty line.
To be relay operated correctly for any fault happeneda long A - B it should has the characteristics above.
But when S/C accurse there isan additional ohm resistanceAdded to the line impedance.
Because of S/C arc.
S
ZS
Zn
At normal cases 0
Distance Relays
:
Us/Is = Zs
Impedance
Us/Is Coss = Zs Coss = Rs ResistiveUs/Is Sins = Zs Sins = Xs Reactance
Is/Us= 1/Zs = Ys Admitance
Is/Us Coss =Ys Coss = G ConductanceIs/Us Sins =Ys Sins = B Suseptance
Distance Relays
)Impedance Relays (
.
Zop = const.
Line
D
D
jX
RZop If Z < Zop Relay will Operate
Because of Z not f() soThis type of relay needDirectional unit, D - D
Making new reconnections on the relay terminals,the circle can Be moved left, up, right or down.
Distance Relays
D
D
R
jX
Zo
Line
Zop
s
Zo = Zop minZo = Zop Cos(s - )
= f()
According to internal angle in the relay () Whichdetermine Zop.min we can draw the following char.
This type of relay needDirectional unit, D - D
Zo = Zop Coss = Rop = const
For = 0
Distance Relays
Changing internal angle ()We'll obtained deferentKinds Of Characteristics
jX
R
D
D
R0
Rop
Line
s
Zo = Zop Sin s = Xop = const = 90 Distance Relays
jX
R
D
D
Xop Zop
Line
s
:
syaleR OHM
eniL
S
poZ
Xj
R54=
)) - s( soC ( * poZ/1
(. ) 54 =
poZ < Z nehw etarepo lliw yaleR
tinu lanoitcerid deen oNsyaler fo epyt siht rof
OHM dellaC yaleR sihTfo etisoppO na sa yaleR
.syaleR MHO
MHO Relays
jX
R
Line
S
=0
Conductance Characteristics
jX
R
Line
S
=90
Reactance Characteristics
MHO Relays
:
syaleR OHM
S
Xj
R
poZ
SZ
poZ
Xj
R
:
m/ )4.1I(/00782 = aR
)5 - 5.0(
)05 5(
.
syaleR ecnadepmI roF
aRmZ SZ
Xj
R
)R( syaleR OHM roF
SZaRmZ
Xj
R
For MHO Relays (X)
Ra
Zm
ZS
jX
R
Impedance Relays
Ra
Zm
ZS
jX
R
Resistance Relays
RaZSZm
jX
R
Inductance RelaysjX
RaZS
Zm
R
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