Advertisement
CARRIER RELAY1NG
Simil ar
equipment i s required
t e rminal of thB
protected l ine s e c t i on .
l ine
sect ion
i s
c on s idered
shou l d be a s s i gned
a
minimize
the p o s s ib i l ity o f int e rference with
bthe r l ine s .
The
t ransmitter -re ceiver
re spond
t o
the
a s s igned
e ither re ce iver may rece ive a s igna l
t ran smitter
at
the
It i s not nece s sary for the rece iver
s e ct ion .
t o
rece ive a s i gnal from it s own t ran smit t e r ,
this c ond i t i on , the fault i s ex-
8 ince
under
t e rnal
and
the
direct ional
b l ocks t r ippkng .
The re fore , it is p o s sible on
two
t e rminal
l ine s t o use two frequencie s in
this carrie r s cheme and obtain two independent
carrier
channe l s
for
funct i on s in two dire c t i on s s imultaneou s ly .
OPERATION OF SCHEME
The ground re l ay
and the type
o r
type HZM
d i st ance re l ay s are
current
and v o ltage
t ions
for .the se re l ay s .
current and v o lt age c ircuit s
the
d-e s imp l ified s chemat i c
ure
The three
impedance e l ement s of the se
1 .
re l ays
are set in the
type d i st ance r e l aying except
set with the type HZM relay .
ment
Z l , i s set
f o r
and
operat e s independent ly
second
e lement , Z2 , i s set for
the
l ine
se ct i on
and s o covers
l ine , but is part i cu l arly a s s o c iated w ith that
p ort i on
which
i s beyond
first
e l ement ; that
l ine ( end z one )
adj acent t o the next s e c t i on�
a l i z ing
po int .
In thi s z one , it is not
sible
t o
determine
whethe r the
fault is just
yond the end of the s e c t i on .
laying , w ithout c arri e r ,
T2 , is used in serie s w ith the
s e c ond
z one impedance
for the breake r
in the next s e c t i on t o c lear .
When u sed in carrier re laying , thi s T2 c ontact
is paral le le d by a c ontact , RRP , c ont r o l led by
carr ie r ,
a s
e_xp lained
at each l inA
Eact
as a unit
and
d iffe rent
frequency t o
set s are tuned t o
frequency
s o that
from the
opp o s ite
end
of
the
e lement contact
t ran smi t t ing auxi l iary
HZ impedance
ope rate d by
u s ing the
u sual c onne c -
For s imp l i c i t y , the
are not shown in
d iagram of Fig
u sual manner for step
when Z3 i s off
The f i r s t
e l e
o f the l ine s e ct i on
9 0%
of
carrie r .
The
about
1 5 0%
the
ent ire
the
sett ing of the
i s , the last
of the
10%
po s
by
d i st ance
indicat ion
w ithin or just be
For d i stance re
a t ime de lay c ontact
contact of the
e lement to a l l ow
t ime
be l ow .
The
third
POS.
RELAY·
RECEIVER
COILS RRH ()iOLDING)&RRT(miPPIN�;CONTACTS RRG,RRP,RRB
"Fig. 2-Simplilied D-C Schematic of the Carrier Control Cir
cuits Using the Type
Break Third Impedance Element Contacts.
e lement , Z3
of the Type HZ Re lay s , i s given a
d i stance
sett ing
prot e c t i on through c ontact T3 , and
carrier t ransmi s s ion .
of
When the Z3 e lement of the Type HZM Re l ay i s
offset
t o
operat e for
e lement
ha s d i r e c t i onal
w i l l
not send
b locking carrier
fault s .
Consequent l y , in the Type HZM Carrier
s cheme , it is ne ce s sary to reve r se the Z3 e l e
ment .
Thi s means that the
prote c t s
"the
s t at i on in stead
remote t e rminal bre ake r .
The synchronous
the direct i onal
se rie s in b oth the type HZ
cept direct i onal cont r o l is omitted when Z3 i s
reve r se d
for Carrier when
relay s .
CARRI ER CONTROL
A.l.ARM, TELEMETERJNG
OR
HZ
Relay With Two Make-One
t o provide comp l e t e back-up
t o
inte rnal
fau l t s , the
charact e r i s t i c s
for externa l
third z one back -up
l ine s
ext ending
out
of the l ine s
adjacent t o the
t imer
mot o r i s
started by
and third e l ement cont act s in
and HZM re l ays ex
u s ing the Type HZM
.6A
start
and
of
the
3
Advertisement
