TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 201108 +.$. +.$.
CT Sizing/ Dimensions Calculations Table of Contents
500kV 500kV 500kV 220kV 220kV 220kV
Line Line Line Line Line Line
Sheet
CTs-1 CTs-1 CTs-3 CTs-2 CTs-2 CTs-2 CTs-3 CTs-1
3 5 8 10 12 14
Enclosure 1
Current transformers calculated magnetizing curves are enclosed for reference. Reference Documents
Single Line Protection Technical Technical Data sheet 500kV CTs class 0.25P20 Technical Technical Data sheet 220kV CTs class 0.25P20 General
The calculations !elo" are done to check the follo"ing. Protections cores "ith lo" im#edance #rotection$
Checking that actual load is less than rated load. Checking that actual ALF ratio is larger than 40kA.
Protection cores "ith high im#edance #rotection$
Calculation o o!erating "oltage sta#le or 40kA through ault current. Checking that actual knee !oint "oltage o CT is higher than t$o ti%es the o!erating "oltage
%easuring cores$
Checking that actual load is less than rated load. Checking actual Fs "alue and !ro!ose &du%%'( loads $here necessar' not to o"erload the instru%ents and %eters during !ri%ar' aults.
&ll resistance values on current transformers secondar' "inding and ca!les are the values at
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 201108 +.$. +.$.
o
)5 C.
CT ratios:
*atios of CTs used for calculations are as under$
500kV Line CTs 50+1A ratio shall #e used or all %etering cores.
500kV Line CTs 2500+1A ratio shall #e used or all rotecti"e cores ece!t #us #ar !rotection cores $hich $ill use 3000+1A.
220kV Line CTs 00+1A ratio shall #e used or all %etering cores.
220kV Line CTs 2400+1A ratio shall #e used or all rotecti"e cores.
220kV Line CTs 2400+1A ratio shall #e used or all cores ece!t %etering core $hich $ill use 00+1A.
The !urden of each Protection Protect ion rela' + %eter is given &##endi, (.
The -urden from ca!les on CTs are !ased on using ca!le core size of mm 2
Distance is calculated from foundation #lan + ma,imum distance is taken for all calculations.
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 2
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
DIA 1 & 2 1. !!"# $ine CTs%1 Current Transformer T'e: $#(%!!)2
Cor e (
*atio
-urden/V& 0000 1
Cla ss 0.2
&L1 1s 666
kn/V 3nee Point Voltage 666
00062500620006(2506*!(&
2
*ct/4 20()(78
00062!!620006(2506)50(& 00062!!620006(2506)50(&
0+!00(5 0+!00(5
5P 5P
20 20
8(5*+2(09(229 8(5*+2(09(229
272!((0 272!((0
7
00062!!620006(2506)50(&
0+!00(5
5P
20
8(5*+2(09(229
272!((0
5
,!!!62500620006(2506)50(&
+!000(5
5P
20
-1)2(09(229
220((0
Core 1: -urden$ %etering e:ui#ment of Line as -elo"$ &6meter ;6meter Var6meter ;h6meter Digital Po"er %eter
0.2V& 0.2V& 0.2V& 0.2V& 0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& 2.95V&
Total connected !urden
5.(5V&
The rated !urden is (5V&< 5.(5V&= i.e. ok. %a,imum secondar' current at actual load /1s> can !e calculated as$ 1s>? Esat / Rct + Actualload @ In 1s ? Anstrumental securit' factor according to AC 0077 sat ? Current transformer saturation voltage *ct? Current transformer secondar' resistance An? Current transformer secondar' rated current 1s> should !e lo"er than ma,imum current "ithstand of the connected meters in order to #rotect meters at #rimar' faults in the s'stem. Ansertion of actual !urden gives 1s>$ 1s> ? 0
/5 + 5.(5 @(
? 2.85
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
%eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< 2.85= i.e ok Core 2. -urden$ Protection e:ui#ment as !elo". P77 Distance Protection *ela' P97( &uto *eclose+ Schnchro6check rela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 2.95V&
Total connected !urden
.(5V&
The rated !urden is 0V&< .(5V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? Eknee / Rct + Actualload @ ln &L1? &ccurac' limiting factor according to AC 0077 knee? Current transformer knee6#oint voltage *ct ? Current transformer secondar' resistance. ln ? Current transformer secondar' rated current. &L1>? )2 / 20 + .(5 @ ( ? 2.82 This corres#onds to a #rimar' current of 2.82@2500& ?92.k&<70k&= i.e. ok Core ,: -urdenB Protection e:ui#ment as !elo". )S&(2 Distance Protection *ela' P97( &uto *eclosure "ith s'nchro6check rela' P(2) ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& 2.95V&
Total connected !urden
.V&
The rated !urden is 0V&< .V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 ?2.)
/ 20 + . @(
This corres#onds to a #rimar' current of 2.78@2500& ?9(.)5k&<70k&= i.e. ok Core : -urdenB Protection e:ui#ment as !elo". P92( -eaker failure *ela' Ca!le S"itchgear to rela' room Total connected !urden
0.(5V& 2.95V& V&
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 7
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
The rated !urden is 0V&< V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )72 /20 + @ ( ?2.2 This corres#onds to a #rimar' current of 2.2@2500& ?90.5k&<70k&= i.e. ok Core :-urdenB Protection e:ui#ment as !elo". P)2 ogh Am#edence -us !ar Differential Protection *ela' Ca!le S"itchgear to rela' room
0.(5V& 2.95V&
Total connected !urden
V&
The rated !urden is 0V&< V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 8(5 ?.98
/27 + @ (
This corres#onds to a #rimar' current of .98@000& ?(0(.)k&<70k&= i.e. ok Calculation of reuire0 o'erating oltage R for t3roug3 falut sta4ilit.
E* ? Afma, /*ct F * ( "here Afma, is the ma,imum availa!le through fault current /Secondar' & * ( is the loo# ca!le resitance u# to connection #oint &s ma,imum through fault current the s"itchgear design short circuit level is used Afma, ?70k& The re:uired o#erating voltage "ill !e$ E* ? (. /27 F 2.95 ? 5).8( V C3ec" of CT core out'ut.
To secure o#ertion at internal faults the CT cores must give a voltage out#ut knee ? 8(5< )(5.92? 2 @ E * = i.e knee6#oint voltage is sufficient.
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 5
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
2. !!"# $ine CTs%, Current Transformer T'e: $#(%!!)2
Cor e ( 2
*atio
-urden/V& 0000 1 0000 1 0+!00(5
Cla ss 0.2 0.2 5P
&L1 1s 666 666 20
kn/V 3nee Point Voltage 666 666 8(5*+2(09(229
00062500620006(2506*!(& 00062500620006(2506*!(& 00062!!620006(2506)50(&
7 5
00062!!620006(2506)50(& 00062!!620006(2506)50(& ,!!!62500620006(2506)50(&
*ct/4 20()(78 20()(78 272!((0
0+!00(5 0+!00(5 +!000(5
5P 5P 5P
20 20 20
8(5*+2(09(229 8(5*+2(09(229 -1)2(09(229
272!((0 272!((0 220((0
Core 1: -urden$ Protection e:ui#ment as !elo". &6meter ;6meter Var6meter ;h6meter Digital Po"er %eter
0.2V& 0.2V& 0.2V& 0.2V& 0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& 2.)0V&
Total connected !urden
5V&
The rated !urden is (5V&< 5V&= i.e. ok. 1s> ? 0 ?
/5 + 5 @(
%eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< = i.e ok. Core 2: Same as Core (= CT6 of DA& ( + 2. Core ,: -urdenB Protection e:ui#ment as !elo". P77 Distance Protection *ela' P97( &uto *eclosure "ith s'nchro6check rela' Ca!le S"itchgear to rela' room Total connected !urden
0.(5V& 0.(5V& 2.)0V& V&
The rated !urden is 0V& < V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 ?.(
/20 + @(
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
This corres#onds to a #rimar' current of .(@2500& ?92.9k& < 70k&= i.e. ok Core : -urdenB Protection e:ui#ment as !elo". )S&(2 Distance Protection *ela' P97( &uto *eclosure "ith s'nchro6check rela' P(2)ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& 2.)0V&
Total connected !urden
.(5V&
The rated !urden is 0V& < .(5V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 /20 + .(5 @( ? 2.82 This corres#onds to a #rimar' current of 2.82@2500& ?92.k&<70k&= i.e. ok
Core : -urden$ Protection e:ui#ment as !elo". P92( -reaker 1ailure P)2 Transformer V Connection Differential rela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 2.)0V&
Total connected !urden
V&
The rated !urden is 0V&< V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 /20 + @( ?.( This corres#onds to a #rimar' current of .(@2500& ?92.925k&<70k&= i.e. ok Core +: -urden$ Protection e:ui#ment as !elo". P(2) ver Load *ela' P *ough -alance rela' P(2)ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& 2.)0V&
Total connected !urden
.(5V&
The rated !urden is 0V&< .(5V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age )
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
&L1>? )2
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
/ 20 + .(5 @ (
?2.82 This corres#onds to a #rimar' current of 2.82@2500& ?92.k&<70k&= i.e. ok
,. !!"# $ine CTs%2
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 9
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Current Transformer T'e: $#(%!!)2
Cor e ( 2 7 5
*atio
-urden/V&
00062500620006(2506*!(& 00062!!620006(2506)50(& 00062!!620006(2506)50(& 00062!!620006(2506)50(& ,!!!62500620006(2506)50(&
0000 1 0+!00(5 0+!00(5 0+!00(5 +!000(5
Clas s 0.2 5P 5P 5P 5P
&L1 1s 666 20 20 20 20
kn/V 3nee Point Voltage 666 8(5*+2(09(229 8(5*+2(09(229 8(5*+2(09(229 -1)2(09(229
*ct/4 20()(78 272!((0 272!((0 272!((0 220((0
Core 1: -urden$ Protection e:ui#ment as !elo". &6meter ;6meter Var6meter ;h6meter Digital Po"er %eter
0.2V& 0.2V& 0.2V& 0.2V& 0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& 2.79V&
Total connected !urden
7.)9V&
The rated !urden is (5V&< 7.)9V&= i.e. ok. 1s> ? 0 /5 + 7.)9 @( ? .0) %eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< .0)= i.e ok. Core 2: -urden$ Protection e:ui#ment as !elo" P(2) ver Load *ela' P *ough -alance rela' P(2) ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& 2.79V&
Total connected !urden
2.8V&
The rated !urden is 0V&< 2.8V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 /20 + 2.8 @ ( ? .2 This corres#onds to a #rimar' current of .2@2500& ?9.09k&<70k&= i.e. ok Core ,: -urden$ Protection e:ui#ment as !elo"
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 8
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
P92( -reaker 1ailure P)2 Transformer V Connection Differential rela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 2.79V&
Total connected !urden
2.)9V&
The rated !urden is 0V&< 2.)9V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 ?.75
/20 + 2.)9 @ (
This corres#onds to a #rimar' current of .75@2500& ?9.k&<70k&= i.e. ok Core .-urdenB Protection e:ui#ment as !elo". P92( -eaker failure *ela' Ca!le S"itchgear to rela' room
0.(5V& 2.79V&
Total connected !urden
2.V&
The rated !urden is 0V&< 2.V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 ?.)
/20 + 2. @ (
This corres#onds to a #rimar' current of .)@2500& ?97.()5k&<70k&= i.e. ok Core :-urdenB Protection e:ui#ment as !elo". G P)2 igh Am#edence -us -ar Differential Protection *ela' Ca!le S"itchgear to rela' room
0.(5V& 2.79V&
Total connected !urden
2.V&
The rated !urden is 0V&< 2.V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 8(5 /27 + 2. @( ? 7. This corres#onds to a #rimar' current of 7.@000& ?(0.09k&<70k&= i.e. ok Calculation of reuire0 o'erating oltage R for t3roug3 falut sta4ilit.
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (0
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
E* ? Afma, /*ct F * ( "here Afma, is the ma,imum availa!le through fault current /Secondar' & * ( is the loo# ca!le resitance u# to connection #oint &s ma,imum through fault current the s"itchgear design short circuit level is used Afma, ?70k& The re:uired o#erating voltage "ill !e$ E* ? (. /27 F 2. ? 57.89 V C3ec" of CT core out'ut.
To secure o#ertion at internal faults the CT cores must give a voltage out#ut knee ? 8(5< )08.8? 2 @ E * = i.e knee6#oint voltage is sufficient.
1. 22!"# $ine CTs%2
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age ((
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Current Transformer T'e: $#(%22!),
Core
*atio
-urden/V&
Class
&L11s
( 2
27006(2006+!!(& 2!!6(200600(&
001 +!0(5
0.2
666 20
kn/V 3nee Point Voltage 666 !225((2.5
2!!6(200600(&
+!0(5
20
!225((2.5
7
2!!6(200600(&
+!/0(5
20
!225((2.5
5
27006(200600(&
00(5
20
750225((2.5
27006(200600(&
00(5
20
750225((2.5
5P 5P 5P 5P 5P
*ct/4 (9
115.52.)5 115.52.)5 115.52.)5 ((5.52.)5 ((5.52.)5
Core 1: -urden$ Protection e:ui#ment as !elo". &6meter ;6meter Var6meter ;h6meter Digital Po"er %eter
0.2V& 0.2V& 0.2V& 0.2V& 0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& (.5)V&
Total connected !urden
.9)V&
The rated !urden is (5V&< .9)V&= i.e. ok. 1s> ? 55 ? .89
/ 7 + .9) @ (
%eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< .89= i.e ok. Core 2: -urdenB Protection e:ui#ment as !elo". P(2) ver Load *ela' P *ough -alance rela' P(2) ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& (.5)V&
Total connected !urden
2.02 V&
The rated !urden is 0V&< 2.02V&= i.e. ok.
&ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750
/(( + 2.02 @ (
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (2
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
?7.5 This corres#onds to a #rimar' current of 7.5@2700& ?9.87k&<70k&= i.e. ok
Core ,: -urdenB Protection e:ui#ment as !elo". P)2 Transformer V Connection Differential rela' Ca!le S"itchgear to rela' room
0.(5V& (.5)V&
Total connected !urden
(.)2V&
The rated !urden is 0V&< (.)2V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 /(( + (.)2 @( ? 5.9 This corres#onds to a #rimar' current of 5.9@2700& ?97.8(k&<70k&= i.e. ok
Core .-urdenB Protection e:ui#ment as !elo". P)2 igh Am#edance -us -ar Differential Protection *ela' Ca!le S"itchgear to rela' room
0.(5V& (.5)V&
Total connected !urden
(.)2V&
The rated !urden is 0V&< (.)2V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 ?5.9
/(( + (.)2 @ (
This corres#onds to a #rimar' current of 5.9@2700& ?97.8(k&<70k&= i.e. ok Calculation of reuire0 o'erating oltage R for t3roug3 falut sta4ilit.
E* ? Afma, /*ct F * ( "here Afma, is the ma,imum availa!le through fault current /Secondar' & * ( is the loo# ca!le resitance u# to connection #oint &s ma,imum through fault current the s"itchgear design short circuit level is used Afma, ?70k&
The re:uired o#erating voltage "ill !e$ E* ? (.) /((F (.)2 ? 2(2.07 V
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
C3ec" of CT core out'ut.
To secure o#ertion at internal faults the CT cores must give a voltage out#ut knee ? 750< 727.09? 2 @ E * = i.e knee6#oint voltage is sufficient. Core : -urdenB Protection e:ui#ment as !elo". Hot Esed Core +: -urdenB Protection e:ui#ment as !elo". Hot Esed
2. 22!"# $ine CTs%, Current Transformer T'e: $#(%22!),
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (7
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Core
*atio
-urden/V&
Class
&L11s
( 2
27006(2006+!!(& 2!!6(200600(&
001 +!0(5
0.2
666 20
kn/V 3nee Point Voltage 666 !225((2.5
2!!6(200600(&
+!0(5
20
!225((2.5
7
2!!6(200600(&
+!0(5
20
!225((2.5
5
2!!6(200600(&
+!0(5
20
!225((2.5
2!!6(200600(&
+!0(5
20
!225((2.5
5P 5P 5P 5P 5P
*ct/4 (9
115.52.)5 115.52.)5 115.52.)5 115.52.)5 115.52.)5
Core 1: -urden$ Protection e:ui#ment as !elo". &6meter ;6meter Var6meter ;h6meter
0.2V& 0.2V& 0.2V& 0.2V&
Digital Po"er %eter
0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& (.9V&
Total connected !urden
7.(V&
The rated !urden is (5V&< 7.(V&= i.e. ok. 1s> ? 55 / 7 + 7.( @( ? .) %eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< .)= i.e ok. Core 2: -urdenB Protection e:ui#ment as !elo". P(2) ver Load *ela' P *ough -alance rela' P(2)ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& (.9V&
Total connected !urden
2.29V&
The rated !urden is 0V&< 2.29V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 ?.99
/(( + 2.29 @(
This corres#onds to a #rimar' current of .99@2700& ?9(.(k&<70k&= i.e. ok
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (5
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Core ,: -urdenB Protection e:ui#ment as !elo". P)2 LV Connection Protection *ela' Ca!le S"itchgear to rela' room
0.(5V& (.9V&
Total connected !urden
(.89V&
&ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 ? 7.)
/(( + (.89 @ (
This corres#onds to a #rimar' current of .)@2700& ?90.9k&<70k&= i.e. ok Core .-urdenB Protection e:ui#ment as !elo". P92( -reaker 1ailure *ela' Ca!le S"itchgear to rela' room Total connected !urden
0.(5V& (.9V& (.89V&
&ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 /(( + (.89 @ ( ?7.) This corres#onds to a #rimar' current of 7.)@2700& ?9.209k&<70k&= i.e. ok Core : -urdenB Protection e:ui#ment as !elo". Hot Esed Core +: -urdenB Protection e:ui#ment as !elo". Hot Esed
,. 22!"# $ine CTs%1 Current Transformer T'e: $#(%22!),
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Core
*atio
-urden/V&
Class
( 2
27006(2006+!!(& 2!!6(200600(&
001 +!0(5
0.2
2!!6(200600(&
+!0(5
7
2!!6(200600(&
+!0(5
5
2!!6(200600(&
+!0(5
2!!6(200600(&
+!0(5
&L11s
5P 5P 5P 5P 5P
20
kn/V 3nee Point Voltage 666 !225((2.5
20
!225((2.5
20
!225((2.5
20
!225((2.5
20
! 225((2.5
*ct/4 (9
115.52.)5 115.52.)5 115.52.)5 115.52.)5 115.52.)5
Core 1: -urden$ Protection e:ui#ment as !elo". &6meter ;6meter Var6meter ;h6meter Digital Po"er %eter
0.2V& 0.2V& 0.2V& 0.2V& 0.5V&
Transducer ; for *ecorder Transducer var for *ecorder Ca!le S"itchgear to rela' room
0.5V& 0.5V& 2.0(V&
Total connected !urden
7.(V&
The rated !urden is (5V&< 7.(V&= i.e. ok. 1s> ? 55 / 7 + 7.( @ ( ? .2 %eter "ith lo"est "ithstand is ;h6meter= "hich can stand 20@ln ? 20< .2= i.e ok. Core 2: -urdenB Protection e:ui#ment as !elo". )S&(2 Distance Protection *ela' P97( &uto *eclosure "ith s'nchro6check rela' P(2)ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 0.(5V& 0.(5V& 2.0(V&
Total connected !urden
2.7V&
The rated !urden is 0V&< 2.7V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 ?.7
/(( + 2.7 @(
This corres#onds to a #rimar' current of .7@2700& ?90.2k&<70k&= i.e. ok Core ,: -urdenB Protection e:ui#ment as !elo".
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age ()
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
P77 Distance Protection *ela' P97( &uto *eclose+ Schnchro6check rela' Ca!le S"itchgear to rela' room Total connected !urden
0.(5V& 0.(5V& 2.0(V& 2.(V&
&ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750 ?.9(
/(( + 2.( @(
This corres#onds to a #rimar' current of .9(@2700& ?9(.(77k&<70k&= i.e. ok Core .-urdenB Protection e:ui#ment as !elo". P)2 igh Am#edance -us -ar Differential Protection *ela' Ca!le S"itchgear to rela' room
0.(5V& 2.0(V&
Total connected !urden
2.(V&
&ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? 750
/(( + 2.( @ (
?7.(8 This corres#onds to a #rimar' current of 7.(8@2700& ?92.05k&<70k&= i.e. ok Calculation of reuire0 o'erating oltage R for t3roug3 falut sta4ilit.
E* ? Afma, /*ct F * ( "here Afma, is the ma,imum availa!le through fault current /Secondar' & * ( is the loo# ca!le resitance u# to connection #oint &s ma,imum through fault current the s"itchgear design short circuit level is used Afma, ?70k& The re:uired o#erating voltage "ill !e$ E* ? (.) /((F 2.( ? 2(8.9 V C3ec" of CT core out'ut. To secure o#ertion at internal faults the CT cores must give a voltage out#ut
knee ? 750< 79.)? 2 @ E * = i.e knee6#oint voltage is sufficient. Core : -urdenB Protection e:ui#ment as !elo". Hot Esed Core +: -urdenB Protection e:ui#ment as !elo". Hot Ese
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (9
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
DIA , 1. !!"# $ine CTs%1 Current Transformer T'e: $#(%!!)2
Cor e ( 2
*atio
-urden/V& 0000 1 0+!00(5 0+!00(5
Cla ss 0.2 5P 5P
&L1 1s 666 20 20
kn/V 3nee Point Voltage 666 8(5*+2(09(229 8(5*+2(09(229
00062500620006(2506*!(& 00062!!620006(2506)50(& 00062!!620006(2506)50(&
7 5
00062!!620006(2506)50(& ,!!!62500620006(2506)50(&
*ct/4 20()(78 272!((0 272!((0
0+!00(5 +!000(5
5P 5P
20 20
8(5*+2(09(229 -1)2(09(229
272!((0 220((0
Core 1: Same as core ( of 5003v line CT6( of DA& ( + 2. Core 2: Same as core 2 of 5003v line CT6( of DA& ( + 2. Core ,: Same as core of 5003v line CT6( of DA& ( + 2. Core : Same as core 7 of 5003v line CT6( of DA& ( + 2. Core : Same as core 5 of 5003v line CT6( of DA& ( + 2.
2. !!"# $ine CTs%, Current Transformer T'e: $#(%!!)2
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age (8
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
Core
*atio
-urden/V&
(
00062500620006(2506 *!(&
0000 1
2
00062500620006(2506 *!(&
0000 1
7 5
00062!!620006(2506)50(& 00062!!620006(2506)50(& 00062!!620006(2506)50(& ,!!!62500620006(2506)50(&
0+!00(5 0+!00(5 0+!00(5 +!000(5
Cl as s 0. 2 0. 2 5P 5P 5P 5P
&L1 1s
kn/V 3nee Point Voltage
*ct/4
666
666
20()(78
666
666
20()(78
20 20 20 20
8(5*+2(09(229 8(5*+2(09(229 8(5*+2(09(229 -1)2(09(229
272!((0 272!((0 272!((0 220((0
Core 1: Same as core ( of 5003v line CT6 of DA& ( + 2. Core 2: Same as core 2 of 5003v line CT6 of DA& ( + 2. Core ,: Same as core of 5003v line CT6 of DA& ( + 2. Core : Same as core 7 of 5003v line CT6 of DA& ( + 2. Core : -urden$ Protection e:ui#ment as !elo". P77 Distance Protection *ela' Ca!le S"itchgear to rela' room Total connected !urden
0.(5V& 2.)0V& 2.95V&
The rated !urden is 0V&< 2.95V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 ?.5
/20 + 2.95 @(
This corres#onds to a #rimar' current of .5@2500& ?9.95k&<70k&= i.e. ok Core +: -urden$ Protection e:ui#ment as !elo". )S&(2 Distance Protection *ela'
0.(5V&
P(2)ver Current *ela' Ca!le S"itchgear to rela' room
0.(5V& 2.)0V&
Total connected !urden
V&
The rated !urden is 0V&< .(5V&= i.e. ok. &ctual &L1 /&L1 can a##ro,. !e calculated as $ &L1>? )2 / 20 + @(
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 20
TEL: 86-21-61610909 FAX: 86-21-61610900 Web:www.syec.com.cn 中国上海市闵行区华宁路 3399 号
No.3399, Hu!n"n# $%, &"n'n# ("s)., *'n#'", 201108 +.$.
?.( This corres#onds to a #rimar' current of .(@2500& ?92.9k&<70k&= i.e. ok
1. !!"# $ine CTs%2 Current Transformer T'e: $#(%!!)2
Cor e (
*atio
-urden/V&
00062500620006(2506*!(&
2
00062!!620006(2506)50(&
00062!!620006(2506)50(&
7
00062!!620006(2506)50(&
5
,!!!62500620006(2506)50(&
00001 0+!00( 5 0+!00( 5 0+!00( 5 +!000( 5
Cla ss 0.2
&L1 1s 666
kn/V 3nee Point Voltage 666
*ct/4 20()(78
5P
20
8(5*+2(09(229
272!((0
5P
20
8(5*+2(09(229
272!((0
5P
20
8(5*+2(09(229
272!((0
5P
20
-1)2(09(229
220((0
Core 1: Same as core ( of 5003v line CT6 of DA& . Core 2: Same as core 5 of 5003v line CT6 of DA& . Core ,: Same as core of 5003v line CT6 of DA& . Core : Same as core 7 of 5003v line CT62 of DA& ( + 2. Core : Same as core 5 of 5003v line CT62 of DA& ( + 2.
CT )i*ing+,i%ension Calculations or 500V )hikar!ur ro/ect
age 2(
