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TYPE HZ OR HZM /bOUBLE
INTRODUC T I ON
The high- speed
transmi s s i on line s
is r e c ognized · as
for good s y s tem
operat i o n .
pro tec tion
i s pl'ovided
different i al r e l aying in which c ond i t ions at the
two ends of the line are c ompared
whether the fault
i s
ternal to the pro t e c ted z one .
multaneous tr ipping of
de s irable
from the s tandpoint s
c ontinuity of s ervic e ,
imum damage to
e quipment .
rier r e laying i s the mo s t prac t i c al and r e l iable
medium
f or c omparing the c ond it ions
ends of the line .
Thi s s y s tem
operat ing on current and vo ltage
the line
t o d e t e c t and de t ermine
of fault s .
Carrier i s s t arted
o r s
when a f a ul t o c c ur s .
out
of a line s e c t ion ind i c a t e s
is external and the breakers should not be t ri p
ped .
·At
the
s rune ins t ant ,
be f lowing
int o t h e
though
t h e f ault
wer e in t he s e c t i o n .
this c ondi t ion,
the direc t i onal
end where power
is f l owing out
wi l l operate
t o c ontinue the transmi s s ion
c arrier s ignal
which is r e c e ived
and prevents
the re lays
ping
f or
all
external
fault s ,
power w i l l not be f lowing
end and c arrier will be s t opped
the dir e c t i onal e l ement s
s imultaneous tr ipping of both breaker s .
The c arrier s c heme ut i l i z e s
d i s tance charac ter i s t ic
r e lay t o provide
high speed
ping with c arrier in s er vi c e ,
tance pr o t e c t i on
w i t h c arrier e i ther
of servic e .
The f ir s t e lement of the type HZ or
HZM r e l ay
opera t e s
independently
The s e c ond
e lement
trips
f ault s
in th e s e c t ion b e c au s e th e c arrier tr ip
ping c ontac t s
short
timer .
The s e tripp ing c ont ac t s
ately
if the f ault
is within the s e c tion,
are held open
by · c arrier to b loc k
the fault i s beyond the s e c t ion be ing pr o t e c ted .
This arrangement
thus
tripping over the ent ire line s e c t i on .
chronous t imer
is u s e d
s e c ond impedanc e e l ement t o provide back- up pro
t e c t ion for
the
se c ond z one s e c t ion .
ping c ir c ui t of the third e l ement is
of c arrier
and
operat e s
o v e r a l l
back- up
�ro t e c t ion .
e lement ,
supervi s ed by the s ec ond impedance e l e
ment ,
t o gether with the third impedanc e e lement ,
c ontr o l the transmi s s ion o f c arrier .
" '· .... .,_ ,
""*-�•'? 'tf � P
OPERAT ION OF SCHEME
c learing
of faul t s on
nec e s s ary
The
b e s t
overall
by the method
known as
t o
de t ermine
in, the
line
s e c t ion or ex
This as sur e s
t h e breaker s ,
which
o f
s t ab i lity ,
quick r e c l o s ing ,
and min
For many line s ,
at the two
of pr o t e c t ion u s e s re lays
at each end of
the direc t i on
by fault de t ec
Fault power
f l owing
that the fault
however ,
power wi l l
o ther e n d
o f t h e
line as
Under
re lays
at the
of the
s e c t i on
at both
at both ends from trip
fault s .
For internal
out at e ither
by operat ion of
at b oth ends
to permit
the t ime
of the type
HZ or
s imultane ous trip
and
step type d i s
in or out
of
c arrier .
at
high
speed
around
the
synchronous
c lo s e
immedi
tr ipping
pr ovide s
s imultaneous
The syn
in c onnec t ion
with the
The trip
independent
with
time
d e lay f o r
The
dir e c t i onal
.
CARRIER RELAYING
PLATE-
Add i ti onal int e r l o c k s
to prevent
tr ipping of any o f the e lement s
r i er or back- up pro t e c t ion
chronism surge s .
l o t pr o t e c t ion,
high s p e e d and t ime d e l ay back- up pr o t ec t i c n .
C OMPONENTS OF C OMPLETE EQUIPMENT
An
s i
outline
i s
each t e rminal
lows :
c ar
l .
current and v ol tag e
det ermine
the direc t i on
breaker
if the f ault f a l l s
pr o t e c t ion,
and t o c ontr o l
c arrier
for ext ernal f ault s .
c arrier r e lays c on s i s t s of :
Type HZ Impedanc e or HZM Di stanc e Relay s
3
f or pha se fault s ,
HHX
l Type
(
P o t ent ial P o lar i z ed
al Overcurrent Ground Relay ,
1
Type RS or RSN C arrier Auxi liary Re lay
l Type C O ,
of a
up R e l ay .
ends
The Type RSN r e l ay
vides out - of- synchr onism blo cking .
Re lay
with the Type R S Rel ay
synchronism surge b lo c k ing,
b locking without add i t ional d i s t anc e e l ement s .
2 .
c e iver s e t ,
the transmitter
HZM
fault detec ting and dire c t i onal r e l ay s ,
r e c e iver to
operate a rec e iver r e lay included in
the Type R S or RSN re lay .
•
Carrier Set .
3 .
fo r
auxiliary
f o r introduc ing the c arrier frequency
onto
the transmi s s ion line .
p l i e d with a p o t ent ial devic e for me a su r ing line
t o - ground p o t en t i al
but
measuring th ree pha s e li ne p o t ential .
if
r i er C oupling c apac i t or is the Type P C ,
the p o t en t i al devic e ,
4.
is u s ed to tune out the c apac i t anc e of the c oup
ling c apac i t or and mat c h
c e iver c ir c ui t s
tuner
is a part
transmit t er r e c e iver is mount e d outdo or s ,
s eparat e ly mounted
when the transmi t t er- r e c e iver i s loc ated indoors
s ome di s t anc e from the tuner .
-
1 -
�; o ' o
/
'
t� ·
• ,
f
/
�
· .r �;... t\ "-'i"' '- · v-
",,
• "
,�:·
"
, - .,.,._.,_-..,· .;x,._.·� • • - ,.,,..,.,, ...,. .
c an be inc luded
)
due t o
Thu s ,
b e s i des the c arrier pi
this
s y s t em inherently pr o v i d e s
of the equipment
of a transmi s s ion line
A s e t of r e lay s ,
operating on the
of the line ,
to det e c t and
of fault s ,
within the
the t r ansmi s s i on of
One t erminal
(
)
current p o lar i z ed
)
Carrier Dire c t i on
CR ,
CRC ,
CWC or CWP Ground Back
with the Type
HZ
provides swing or
but not out- of- s tep
A d- e
c arrier
t r ansmit t er- r e-
c ontrolled by
This
is the
A c oupling c apac itor
Thi s may
or
s e t s
c an be u s ed
3
is usually the Type P C A .
A Line C oup l ing Tuner .
the
transmi t t er or re
t o the transmi s s ion line .
of the c arrier
s e t
near the c oupling
4 1- 6 0 0 . 6
)
(
c ar
out- of- syn
u s e d
at
is as f o l
to trip the
zone
of
of
or Type HRP
Re lays pro
The Type
HZM
the
and the
JY
Type
with c arrier
be
s up
for
The C ar
and with
Thi s unit
The
when
the
or i s
c apac itor
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