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