The grou d motion can b des rib d by natural time histories when k own, or by artif i ial time histories, whic s ould comply with the RRS; this is u ed as input for d namic analy is or v
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Trang 4CONTENTS
FOREWORD 4
INTRODUCTION 6
1 Sco e 7
2 Normative ref eren es 7
3 Terms an def i ition 7
4 Symb ls an a breviated terms 8
5 Method of seismic q al f i ation 9
6 Severities 10 6.1 At the grou d 10 6.2 At the bu hin f lan e 10 7 Qualf i ation by static calc lation 11 8 Qualf i ation by d namic analy is 13 8.1 General 13 8.2 Modal analy is u in the time-history method 14 8.3 Modal analy is u in the RRS 14 9 Qualf i ation by vibration test 14 9.1 General 14 9.1.1 General 14 9.1.2 Mou tin 15 9.1.3 External lo d 15 9.1.4 Me s rements 15 9.1.5 Stan ard f req en y ran e 15 9.1.6 Test method 15 9.1.7 Testin 17 9.2 Test on complete a p ratu 18 9.3 Test on the bu hin mou ted on a simulatin s p ort 18 9.4 Test on the bu hin alone 18 10 Evaluation of the seismic q al f i ation 18 10.1 Combination of stres es 18 10.2 Canti ever test 19 10.3 Ac e tan e criteria 19 1 Neces ary ex han e of inf ormation 2
1 1 Inf ormation s p l ed by the a p ratu man f acturer 2
1 2 Inf ormation s p l ed by the bu hin man f acturer 2
An ex A (inf ormative) Flow c art f or seismic q al f i ation 2
An ex B (inf ormative) Natural f req en y an dampin determination: Fre os i ation test 2
B.1 Fre os i ation test 2
B.2 Sine swe p f req en y se rc 2
An ex C (inf ormative) Static calc lation method – Ad itional con ideration 2
C.1 General 2
C.2 Ef f ect of the f irst b n in mode 2
C.3 Determination of S c 2
C.4 Value of a bg 2
Trang 5C.6 Sup relevation f actor K 2
An ex D (inf ormative) Qualf i ation by static calc lation – Example on tran f ormer bu hin 3
D.1 Seismic grou d motion 3
D.2 Critical p rt of the bu hin 3
D.3 Static calc lation 33 D.3.1 General 3
D.3.2 Seismic lo d 3
D.3.3 Win lo d 35 D.3.4 Terminal lo d 35 D.4 Guaranteed b n in stren th 3
An ex E (inf ormative) Center clamp d bu hin s 3
Bibl ogra h 4
Fig re 1 – Example of model of the tran f ormer s stem 14 Fig re 2 – RRS f or grou d mou ted eq ipment – ZPA = 0,5 g [1] [2] 17 Fig re 3 – Resp n e f actor R 21
Fig re 4 – Test with simulatin s p ort ac ordin to 9.3 22 Fig re 5 – Determination of the severity 2
Fig re A.1 – Flow c art f or seismic q al f i ation 2
Fig re B.1 – Typical case of f re os i ation 2
Fig re B.2 – Case of f re os i ation with b ats 2
Fig re C.1 – Sin le degre of f re dom s stem 2
Fig re C.2 – Stru ture at the f lan e of a bu hin with cemented p rcelain [5] [7] 2
Fig re C.3 – Sprin stif f nes C in f un tion of cemented p rt ge metry [5] [7] 2
Fig re C.4 – Sup relevation f actor d e to the existen e of tran f ormer b d an f ou dation [5] 3
Fig re D.1 – Critical p rt of the bu hin 3
Fig re D.2 – Forces af f ectin the bu hin 3
Fig re D.3 – Porcelain diameters 3
Fig re E.1 – Fai ure proces [6] 3
Fig re E.2 – Fai ure proces , f low c art [5] [6] 3
Fig re E.3 – Stres prof ile d rin the o enin proces [6] 3
8 Fig re E.4 – Relation b twe n compres ion an ten i e stres in the b tom ed e of the p rcelain d e to the o enin proces [6] 3
Ta le 1 – Grou d ac eleration levels 10 Ta le 2 – Dy amic p rameters o tained f rom exp rien e on bu hin s with p rcelain in ulators (f 0 = natural f req en y, d = dampin ) 12 Ta le 3 – Dy amic p rameters o tained f rom exp rien e on bu hin s with comp site in ulators (f 0 natural f req en y, d = dampin ) 12 Ta le 4 – Example of q al f i ation level: AG5: ZPA = 0,5 g 17 Ta le 5 – Resp n e f actor R 21
Ta le C.1 – Examples of typical seismic resp n es 31
Trang 6INTERNATIONAL ELECTROTECHNICAL COMMISSION
_ _ _ _ _ _
1 Th Intern tio al Ele trote h ic l Commis io (IEC) is a worldwid org niz tio for sta d rdiz tio c mprisin
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Tec nical sp cif i ation are s bject to review within thre ye rs of publ cation to decide
whether they can b tran f ormed into International Stan ard
IEC 614 3, whic is a Tec nical Sp cif i ation, has b en pre ared by s bcommite 3 A:
In ulated bu hin s, of IEC tec nical commit e 3 : In ulators
Trang 7The text of this doc ment is b sed on the f ol owin doc ments:
En uiry draft Re ort o v tin
Ful inf ormation on the votin f or the a proval of this doc ment can b f ou d in the re ort on
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This publ cation has b en draf ted in ac ordan e with the ISO/IEC Directives, Part 2
The commite has decided that the contents of this publ cation wi remain u c an ed u ti
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related to the sp cif i publcation At this date, the publcation wi b
• tran f ormed into an International stan ard,
• recon rmed,
• with rawn,
• re laced by a revised edition, or
A bi n ual version of this publ cation may b is ued at a later date
IMPORTANT – Th 'colour in ide' logo on the cov r pa e of this publ c tion in ic te
that it contains colours whic are con idere to be us f ul for th cor e t
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colour printer
Trang 8INTRODUCTION
As it is not alway p s ible to def i e ac urately the seismic severity at the bu hin f lan e
level, IEC TS 614 3, whic is a Tec nical Sp cif i ation, presents thre alternative method
of q al f i ation The thre method are eq al y ac e ta le If the req ired respon e sp ctrum
(RRS) at the bu hin f lan e is not k own, a severity (in terms of ac eleration values) b sed
on stan ard resp n e sp ctra at the grou d level may b u ed to car y out q al f i ation
throu h one of the thre method des rib d in this doc ment
When the en ironmental c aracteristic are not s f f iciently k own, qualf i ation by static
calc lation is ac e ta le Where hig saf ety rel a i ty of eq ipment is req ired f or a sp cif i
en ironment, precise data are u ed, theref ore q al f i ation by d namic analy is or vibration
test is recommen ed The c oice b twe n vibration testin an d namic analy is de en s
mainly on the ca acity of the test f aci ty f or the mas an volume of the sp cimen, an , also
if non-l ne rities are exp cted
When q al f i ation by d namic analy is is f orese n, it is recommen ed that the n merical
model b adju ted by u in vibration data (se Clau e 5)
This doc ment was pre ared with the intention of b in a pl ca le to bu hin s whatever their
con tru tion material an their internal con g ration.The inf ormation contained, original y
directed to p rcelain bu hin s, has b en p rtial y updated to in lu e also comp site
bu hin s
Trang 9BUSHINGS – SEISMIC QUALIFICATION
IEC TS 614 3, whic is a Tec nical Sp cif i ation, is a pl ca le to alternatin c r ent an
direct c r ent bu hin s f or hig est voltages a ove 5 kV (or with resonan e f req en ies
placed in ide the seismic respon e sp ctrum), mou ted on tran f ormers, other a p ratu or
bui din s For bu hin s with hig est voltages les than or eq al to 5 kV (or with resonan e
f req en ies placed outside f rom the seismic resp n e sp ctrum), d e to their c aracteristic ,
seismic q al f i ation is not u ed as f ar as con tru tion practice an seismic con tru tion
practice comply with the state of the art
This doc ment presents ac e ta le seismic q al f i ation method an req irements to
demon trate that a bu hin can maintain its mec anical pro erties, in ulate an car y c r ent
d rin an af ter an e rth uake
The seismic q al f i ation of a bu hin is only p rf ormed up n req est
2 Normative ref erences
The f ol owin doc ments are ref er ed to in the text in s c a way that some or al of their
content con titutes requirements of this doc ment For dated ref eren es, only the edition
cited a pl es For u dated ref eren es, the latest edition of the ref eren ed doc ment
(in lu in an amen ments) a pl es
IEC 6 0 8-2-4 , Enviro me tal testing – P art 2-47 : Te t – M ou tin of s e ime s for
vibratio , imp ct a d similar d yn mic tests
IEC 6 0 8-2-5 , Enviro me tal testing – P art 2-57 : Te ts – Te t Ff: Vibratio – Time-history
a d sin -b at method
IEC 6 0 8-3-3:19 1, Enviro me tal testing – P art 3-3: Guid an e – Seismic test method s for
IEC 6 13 , I ns lated b s ing for altern tin v ltag s a o e 1 0 0 V
IEC 614 2, Comp site h llow in ulators – P re s rized a d u pre s rized ins lators for u e
in electrical e uipme t with rated v ltag gre ter tha 1 0 0 V – Definitio s, test methods,
a c ptan e criteria a d d esig re omme d ation
IEC 6 15 , H ollow pres urized a d u pre s rized c ramic a d glas in ulators for u e in
electrical e uipme t with rated v ltag s gre ter tha 1 0 0 V
IEC 6 217, P olymeric in ulators for ind oor a d o td oor u e – Ge eral d efinitio s, test
method s a d a c ptan e criteria
ISO 2 41, M ec a ical vibratio , s o k a d c nd ition mo itoring – Vo a ulary
3 Terms and def initions
For the purp ses of this doc ment, the terms an def i ition given in IEC 6 0 8-3-3,
IEC 6 13 , IEC 614 2, ISO 2 41 an the f ol owin a ply
Trang 10ISO an IEC maintain terminological data ases f or u e in stan ardization at the f ol owin
• IEC Electro edia: avai a le at ht p:/www.electro edia.org/
• ISO Onlne browsin platf orm: avai a le at ht p:/www.iso.org/o p
3.1
critic l cros -s ction
section of the bu hin that is most l kely to f ai d rin an e rth uake
3.2
plot of the maximum resp n e to a def i ed input motion of a f ami y of sin le-degre of
-f re dom b dies at a sp cif ied dampin ratio
[SOURCE: IEC 6 0 8-2-5 :2 13, 3.18, modif ied — The word "as a f un tion of their natural
f req en ies an at a sp cif ied dampin ratio" has b en re laced by "at a sp cif ied dampin
predominant f req en ies of a typical e rth uake
Note 1 to e try: This ra g is g n raly b twe n 0,3 Hz a d 3 Hz
Note 2 to e try: This ra g is s ficie t to d termin th critic l fe u n ie of th e uipme t a d for its te tin
In c rtain c s s th te t fe u n y ra g ma b e te d d or re u e d p n e t o th critic l fe u n ie
pre e t, b t this s al b ju tifie
3.5
zero period a c leration
hig f req en y as mptotic value of ac eleration of a resp n e sp ctrum (a ove the c t-of f
distan e b twe n the centre of gravity of the p rt of the bu hin whic is u der
con ideration an the critical cros -section
f
0
f irst natural f req en y of the bu hin
Trang 11K s p relevation f actor b twe n grou d an bu hin f lan e: f actor ac ou tin f or the
c an e in the ac eleration f rom the grou d to the f lan e d e to the ampl f i ation by
R resp n e f actor derived f rom the req ired resp n e sp ctrum (RRS) as the ratio
b twe n the resp n e ac eleration an the Z A (se Fig re 3)
RRS req ired resp n e sp ctrum: resp n e sp ctrum sp cif ied by the u er
S
c
co f f icient esta l s ed to take into ac ou t the ef f ects of b th multif req en y
ex itation an multimode resp n e
5 Methods of seismic qual f ication
Seismic q al f i ation s ould demonstrate the a i ty of a bu hin to with tan seismic
stres es an to maintain its req ired f un tion without f aiure, d rin an af ter an e rth uake
of a sp cif ied severity (se Clau e 6)
As bu hin s are mou ted on a p ratu or bui din s, the seismic q al f i ation of the bu hin
mu t con ider the b haviour of the s stem on whic the bu hin is f i ed In the seismic
q al f i ation of a bu hin , al p rts s ould b in lu ed, whic contribute to the stres es in the
critical cros -section d rin a seismic event, f or example the con u tor an in er sp cer in
gas in ulated bu hin s
Thre method an combination there f are des rib d in this doc ment:
– q al f i ation by static calc lation (Clau e 7);
– q al f i ation by d namic analy is (Clau e 8);
– q al f i ation by vibration test (Clau e 9)
A combination of the method may b u ed
– to q al f y a bu hin whic can ot b q al f ied by testin alone (e.g b cau e of size
an /or complexity of the a p ratu ),
– to q al f y a bu hin alre d tested u der dif f erent seismic con ition , an
– to q al f y a bu hin simiar to a bu hin alread tested but whic in lu es modif i ation
in uen in the d namic b haviour (e.g c an e in the len th of in ulators or in the mas )
Vibrational data (dampin , critical f req en ies, stres es of critical elements as a f un tion of
input ac eleration) f or analy is can b o tained by
a) a d namic test on a simi ar bu hin ,
b) a d namic test at red ced test level, an
c) determination of natural f req encies an dampin by other tests s c as f re os i ation
tests or sine swe p tests (se An ex B)
The method res lt in the value of M
s
whic is determined f or e c p rt of the bu hin on
either side of the f lan e The stres d e to this moment s ould b combined with the other
stres es actin in the bu hin , an it s ould b demon trated that the bu hin with tan s the
combined stres (Clau e 10)
The dif f erent method of seismic q al f i ation are i u trated in the f low c art given in An ex
A
Trang 126 Se erities
6.1 At the ground
The grou d ac eleration de en s up n the seismic con ition of the site where the
a p ratu is to b located When it is k own, it s ould b pres rib d by the relevant
sp cif i ation Otherwise, the severity level s ould b selected f rom Ta le 1
Table 1 – Ground ac eleration le els
Richter
s ale mag itude
UB
zo eaIntensity MSK
Valu s for AG2 a d AG3 are o tain d b multiplyin th v lu s fom Fig re 2 b 2/5 a d 3/5 re p ctiv ly
The selected q al f i ation level s ould b in ac ordan e with exp cted e rth uakes of
maximum grou d motion f or the site location, f or whic certain stru tures, s stems an
comp nents are desig ed to remain f un tional These stru tures are those es ential to
as ure pro er f un tion, integrity an saf ety of the total s stem (S
2
ac ordin to IEC 6 0 8-3-3)
For q alf i ation, it s ould b as umed that
– the horizontal movements as des rib d in Ta le 1 act in an direction
– the severities of the vertical ac eleration are 5 % of the horizontal (if a dif f erent value is
u ed, a ju tif i ation s al b provided), an
– b th direction may re c their maximum values simultane u ly
The grou d motion can b des rib d by natural time histories when k own, or by artif i ial
time histories, whic s ould comply with the RRS; this is u ed as input for d namic analy is
or vibration test on the complete a p ratu
NOT Informatio o th c relatio b twe n s ismic q alfic tio le els, s ismic z n a d s ismic s ale is
giv n in IEC6 7 1 2-6 [1]
1
a d IEC 6 0 8-3-3
6.2 At the bus ing fla ge
The severity at the bu hin f lan e (se Fig re 5) may b avai a le f rom the man f acturer of
the a p ratu an stru tures (i.e tran f ormers, gas in ulated a p ratu es (GIS), bui din ) in
terms of RRS or maximum ac eleration (a
f Where no inf ormation is avaiable, the f ol owin
simplf ied f ormula is u ed in order to esta l s an ac eleration value at the f lan e of the
Trang 13– calc lated by f i ite element analy is in lu in soi interaction or an other caref ul
model n , or
– derived f rom res lts f rom calc lations or tests on comp ra le a p ratu or stru tures, or
– taken f rom typical values o tained f rom exp rien e
So f ar, very l tle exp rien e is re orted Unles more b c grou d inf ormation is avai a le, K
s ould b as umed to b 1 f or throu h-wal bu hin s, 1,5 f or GIS bu hin s an f or
tran f ormer bu hin s directly mou ted on the tran f ormer cover, an 2 f or tran f ormer
bu hin s mou ted on a tur et If the mou tin con g ration on the tran f ormer is not k own,
K wi b as umed as 1,5
Se also IEC 6 0 8-3-3:19 1, Ta le 4
7 Qual f ication by static calculation
This method is vald f or rigid eq ipment It may b exten ed to f lexible eq ipment, s c as a
bu hin , takin into con ideration the resp n e f actor R, as an alternative to the method by
analy is This al ows simpler evaluation with in re sed con ervatism
Usin the static calc lation method, the b n in moment in the critical cros -section of the
p rt of the bu hin u der con ideration is calc lated f rom an eq ivalent ac eleration of the
centre of gravity of that p rt (a
b):
The value R can b esta l s ed by one of the f ol owin method
a) From the sp ctrum at the bu hin f lan e (if avai a le)
b) When the sp ctrum at the bu hin f lan e is not k own, the sp ctrum at the grou d
(Fig re 2) may b used as umin that the levels at al f req en ies are eq al y ampl f ied
(K f actor) f rom the grou d to the f lan e For s c cases, the values of R are s mmarized
in Fig re 3 The value of R is derived f rom the RRS (Fig re 2 an Ta le 4) by dividin the
sp ctrum values with the ZPA value of as mptotic ac eleration
In order to cor ectly u e the R values, it is neces ary to k ow the f irst natural f req en y f
0
an the dampin d % of the bu hin mou ted on its s p ortin stru ture The natural
f req en y can either b calc lated as in icated f or the s p relevation f actor or f ou d by a
f re os i ation test as des rib d in An ex B
c) R may b as umed to b eq al to 2,5 when inf ormation f or f requen y f
0
an dampin d %
of the bu hin mou ted on a tran f ormer is not avai a le The value of 2,5 cor esp n s to
the f req en y ran e 1,1 Hz to 8 Hz an 5 % dampin ratio (re to Fig re 3 an Ta le 5)
Trang 14d) R may b as umed to b eq al to 2,9 when inf ormation f or f req en y f
0
an dampin d %
of the bu hin mou ted on a GIS stru ture is not avai a le The value of 2,9 cor esp n s
to the f req en y ran e 1,1 Hz to 8 Hz and 3 % dampin ratio (re to Fig re 3 an Ta le
5)
Dif f erent R values can b agre d b twe n purc aser an man f acturer if ju tif ied
Col ected data s ow that the f irst natural f req en y of a mou ted bu hin is lower than that
of the bu hin itself Re orted natural f req en ies s ow a gre t variation, whi e the dampin
ratios l e within a l mited ran e (se Ta le 2 an Ta le 3)
An example of the a pl cation of the method f or bu hin s mou ted on a tran f ormer is given
NOT 1 In th c s of s e ial dis ip tin s stems, hig er d mpin ratio c n b o tain d
NOT 2 Ad itio al d ta wi b in lu e in this ta le b s d o e p rie c of th pra tic l a plc tio of this
te h ic l s e ific tio
Table 3 – Dy amic parameters obtain d from e perie c on
bus ing with composite ins lators (f
Trang 158 Qual f ication by dy amic analysis
For d namic analy is, the whole stru ture, the a p ratu an the grou d con ition in lu in
f ou dation , with the mou ted bu hin , s ould b model ed by f i ite elements or other
mathematical model n tec niq e, takin into con ideration the sp cif i values of elasticity
an dampin of al elements as wel as the relevant mas es The stru ture may b as umed
to b have lne rly an elastical y ex e t sp cial seismic eq ipment (se 10.3, c) , whic
s ould b model ed with its actual pro erties The l ne r values u ed s ould cor esp n to
the values exp cted at the seismic lo d level
Natural f req en ies of the bu hin , the roc in motion of the f ou dation an resp n es at the
to of the bu hin are in uen ed by the mas of the f ou dation, by the sprin con tant an
by the dampin co f f icient of soi When the natural f req en y of the bu hin an the one of
the roc in motion are coin ident, resonant phenomena oc ur an hig resp n e at the to
of the bu hin can b prod ced
If then the con ition of the soi is not go d (sof t), the model n of the total tran f ormer s stem
(soi – f ou dation – tran f ormer b d – tur et – bu hin , ref er to Fig re 1) wi b neces ary
The model in Fig re 1 is an example of the whole s stem [3]
K
H
,C
H: Horiz ntal s rin c n ta t a d d mpin c eficie t at th b tom of fo n atio
K
R
,C
R: Rotatio al s rin c n ta t a d d mpin c eficie t at th b tom of fo n atio
K
H
,C
H: Horiz ntal s rin c n ta t a d d mpin c eficie t at th sid of fo n atio
1
K
2,C
2
K
3,C
3
K
H,C
H
K
R,C
R
K
H,C
HK
R,C
Trang 16R
,C
R: Rotatio al s rin c n ta t a d d mpin c eficie t at th sid of fo n atio
Figure 1 – Ex mple of model of th tra sformer s stem
From the calc lation, the stres es in the critical cros -section of the bu hin can b f ou d
A d namic analy is may b p rf ormed on a bu hin alone if the f lan e severity is alre d
k own
The general proced re is to esta l s , u in exp rimental data, a mathematical model as the
previou s own of the stru ture in order to as es its d namic c aracteristic an then to
determine the resp n e, u in either of the method des rib d in 8.2 and 8.3 Other methods
may b u ed if they can b ju tif ied
8.2 Modal a aly is using the time-history method
When the time-history method is u ed f or seismic analy is, the grou d motion ac eleration
time-histories s al comply with the RRS (se Fig re 2) Two typ s of s p rimp sition may
general y b a pled de en in on the complexity of the pro lem:
– se arate calc lation of the maximum resp n es d e to e c of the thre direction (x an
y in the horizontal, an z in the vertical direction) of the e rth uake motion The ef f ects of
e c sin le horizontal direction an the vertical direction s al b then combined by takin
the s uare ro t of the s m of the s uares, i.e (x
ma2
+ z
ma2
)/2
an (y
ma2
+ z
ma2
)/2
The gre ter of these two values is u ed f or the combination of the stres es of the
bu hin ;
– simultane u calc lation of the maximum resp n es as umin one of the seismic
horizontal direction an the vertical direction (x with z)
ma
an , there f ter, calc lation of
the other horizontal direction an the vertical direction (y with z)
ma This me ns that, af ter
e c ste of calc lation, al values (f orce, stres es) are s p rimp sed alge ricaly The
gre ter of these two values is u ed f or the combination of the stres es of the bu hin
8.3 Modal a aly is using the RRS
When the RRS method is u ed f or seismic analy is, the proced re of combinin the stres es
is des rib d f or an orthogonal s stem of co-ordinates in the main axes of the bu hin an
with x an y in the horizontal an z in the vertical direction The maximum values of stres es
in the bu hin f or e c of the three direction x, y an z are o tained by s p rimp sin the
stres es calc lated f or the variou modal f req en ies in e c of these direction by takin
the s uare ro t of the s m of the s uares The maximum values in the x an z direction —
an in the y an z direction — are o tained by takin the s uare ro t of the s m of the
s uares (x
ma2
+ z
ma2
)/2
an (y
ma2
+ z
ma2
)/2
The gre ter value of these two cases (x, z)
or (y, z) is u ed f or the combination of the stres es of the bu hin
9 Qual f ication by vibration test
9.1.1 Ge eral
Thre dif f erent a pro c es can b a pl ed:
– test on the complete a p ratu (bu hin mou ted on the re l a p ratu );
– test on the bu hin mou ted on a simulatin s p ort;
– test on the bu hin alone
The proced re f or q al f i ation by test s al b in ac ordan e with IEC 60 6 -2-5 an
IEC 6 0 8-3-3 The tests s al b made at the ambient air temp rature of the test location
Trang 17an this temp rature s al b recorded in the test re ort Af ter the vibration test, the bu hin
s al p s a routine test ac ordin to IEC 6 13
9.1.2 Mounting
General mou tin req irements are given in IEC 6 0 8-2-4 The sp cimen s ould b
mou ted as in service in lu in damp rs (if an )
NOT For more d taie g id n e in th c s of e uipme t n rmaly u e with vibratio is lators, s e A.5 of
IEC 6 0 8-2-6:2 0 [2]
The orientation an mou tin of the sp cimen d rin con itionin s ould b pres rib d by
the relevant stan ard They are the only con ition f or whic the sp cimen is con idered as
complyin with the req irements of the stan ard, u les adeq ate ju tif i ation can b given
f or exten ion to an u tested con ition (f or in tan e, if it is proved that the ef f ects of gravity
do not in uen e the b haviour of the sp cimen)
9.1.3 External loa
General y, electrical and en ironmental service lo d can ot b simulated d rin the seismic
test This a pl es also to p s ible internal pres ure of the bu hin d e to saf ety req irements
These weig ts re resent the lower ran e of weig t as ociated with con u tor con ection
hardware an p rt of the weig t of con u tors con ected to the bu hin
Other mas es could b agre d b twe n p rts
NOT For c mbin tio of s ismic a d s rvic lo d to b ta e into a c u t d rin static or d n mic a aly is,
Trang 189.1.6.2 Parameters f or time-history
9.1.6.2.1 Ge eral
The total d ration of the time-history s ould b a out 3 s of whic the stron p rt not les
than 2 s The test method s al b in ac ordan e with IEC 6 0 8-2-5
9.1.6.2.2 Te t s v rity
The test severity s al b c osen in ac ordan e with 6.1
The recommen ed resp n e sp ctra are given in Fig re 2 f or the dif f erent q al f i ation
levels The c rves are related to 2 %, 3 %, 5 %, 10 % of the bu hin dampin If dampin is
a pl ed f or GIS bu hin s, in ac ordan e with 7c) an 7d)
Sp ctra f or dif f erent dampin values may b o tained by l ne r interp lation
9.1.6.2.3 Spe trum def inition
The f ol owin expres ion give the RRS sp ctrum values: de en in on the level (hig ,
medium, low), the rig t RRS wi b given in f un tion of the f req en y
, 0,2g)
Trang 19Figure 2 – RRS f or ground mounte e uipme t – ZPA = 0,5 g [1] [2]
The other sp ctra related to medium level (ZPA = 0,3 g) an low (ZPA = 0,2 g) level can b
e si y o tained by the a ove expres ion
Table 4 – Ex mple of qual fic tion le el: AG5: ZPA = 0,5 g
Frequ nc
Hz
Re p ns a c leratio
m/s2
Dampin ratio
9.1.6.3 Parameters for sin -be t
Test f req en ies s ould cover the f req en y ran e stated in 9.1.5 with half octave sp cin ,
an s ould in lu e the resonan e f req en ies of the sp cimen The test method s ould b in
ac ordan e with IEC 6 0 8-2-5
9.1.7 Te ting
9.1.7.1 Te t a e
The test axes s ould b c osen ac ordin to 3.19 of IEC 6 0 8-3-3:19 1 In some cases, the
ef f ect of the vertical ac eleration res lts in negl gible stres es, an the vertical ex itation may
Trang 209.1.7.2 Te t s que c
The test seq en e s ould b as f ol ows
a) Vibration resp n e in estigation
The vibration resp n e in estigation s ould b car ied out ac ordin to 10.1 an 14.2 of
IEC 6 0 8-3-3:19 1 over the f req en y ran e stated in 9.1.5
b) Seismic q alf i ation test
The test s ould b p rf ormed by a plyin one of the proced res stated in f low c art A.3
(ex e t test Fc) or f low c art A.4 of IEC 6 0 8-3-3:19 1 de en in on the test f aci ties
The test s ould b p rf ormed on e at the level c osen in Clau e 6
Durin the seismic test, the me s rements as stated in 9.1.4 s ould b recorded
9.2 Te t on complete apparatus
When the size an /or complexity of the a p ratu al ow as embly on the s aker ta le, a test
on the complete a p ratu is recommen ed
The test severity s ould b c osen in ac ordan e with 6.1 The time-history method is
recommen ed sin e it more closely simulates the actual con ition , p rtic larly if the
b haviour of the sp cimen u der test is not l ne r
9.3 Te t on the bus ing mounte on a simulating s pport
The bu hin is mou ted on a simulatin s p ort whic is f astened to a s aker ta le
(se Figure 4) The simulatin s p ort has to dy amical y re rod ce (stif f nes an dampin )
the actual a p ratu
The severity an test method s ould b as des rib d in 9.2
9.4 Te t on the bus ing alone
If the size an /or complexity of the a p ratu ( ran f ormer, GIS a p ratu , bui din ) do s not
al ow the test to b p rf ormed as des rib d in 9.2 or 9.3, the test s ould b p rf ormed on the
bu hin alone, rigidly con ected to the s aker ta le In this case, the severity s ould b the
RRS or the p ak ac eleration value at the f lan e of the bus in (se 6.2 an Fig re 5)
The sine-b at test method is recommen ed In case the RRS at the f lan e is not avai a le,
co f f icients K an R s ould b either o tained by calc lation or taken f rom the values given
in Clau es 6 an 7
10 Ev luation of the seismic qual f ication
10.1 Combination of stre s s
The seismic stres es determined as des rib d in Clau es 7, 8 or 9 s ould b combined with
other service stres es to evaluate the total stres in u ed by al the combined lo d on the
bu hin
The pro a i ty of an e rth uake of the recommen ed seismic q al f i ation level oc ur in
d rin the l f etime of the bu hin is low, as the maximum seismic lo d in a natural
e rth uake would only oc ur if the bu hin were ex ited at its critical f req en ies with
maximum ac eleration As this would last only a f ew secon s, a combination of extreme
electrical an environmental service lo d would le d to u re l stic con ervatism
Trang 21Con eq ently, the f ol owin stres es are con idered to oc ur simultane u ly, if not otherwise
sp cif ied (se IEC 6 15 ):
– the stres of an o eratin lo d eq al to 7 % of the canti ever o eratin lo d sp cif ied f or
the bu hin (canti ever is a f orce a pl ed p rp n ic larly to the bu hin axis in the mid le
p rt of the bu hin HV terminal; make ref eren e to the canti ever ta le of IEC 6 13 ,
o eratin lo d );
– the stres of win pres ure of 7 Pa;
– the stres determined by the comp nents of the mas of the bu hin whic acts
p rp n ic lar to the bu hin axis;
– the stres of the average internal pres ure at normal service con ition ;
– the stres in u ed by the seismic event (Clauses 7, 8 or 9)
These stres es can either b in lu ed in the test or analy is model, or se arately ad ed
NOT 1 This c mbin tio of stre s s a s me th t c n e tio ln s d n t lmit th motio of th termin l of th
b s in d rin th s ismic e e t
NOT 2 As this lo d c mbin tio is b s d o a re s n ble c n erv tism, it is p s ible th t it d e n t a ply to
e c in talatio
NOT 2 This c mbin tio of stre s s wi n t b u e d rin th vibratio al te ts, whic are refere to in 9.1.2
(e tern l lo d), b t o ly for static a d d n mic a aly is
10.2 Ca ti e er te t
A canti ever test can b u ed to f i d the hig est p rmis ible stres of the bu hin to b
determined
A canti ever test can b p rf ormed on a complete bu hin or on p rts of it When testin a
se arate in ulator, the clampin ar an ement s al b eq al to that of the complete bu hin
The test proced re s al b in agre ment with IEC 6 13
10.3 Ac epta c criteria
The bu hin s al in ulate an car y c r ent d rin an af ter the e rth uake No crac ,
le kage, p rmanent def lection or relative movement of p rts is p rmited
The bu hin is con idered to b q al f ied f or the seismic req irement if
a) – its comp nents made by cast e ox resin , ceramic materials or glas es are not
stres ed over the 10 % of their typ test with tan b n in moment, in ac ordan e with
IEC 6 217 an IEC 6 15 ,
b) – its comp nents made by comp site material are not stres ed over 1,5 times their
maximum mec anical lo d (MML), whic cor esp n s normal y to the elasticity l mit of the
material, in ac ordance with IEC 614 2, an
NOT Difere t a c pta c criteria c n b a re d b twe n p rc a er a d ma ufa turer, in a c rd n e to
oth r Sta d rd or Sp cific tio s
c) – metal c p rts are not stres ed a ove the yieldin p int by the combined stres es
As embly f itin s, sp cial y desig ed f or seismic purp se (e.g to red ce the natural
f req en y or in re se the dampin ) may however u e f riction an d cti ty in a control ed
way
By con iderin the actual stres -strain relation hip an stres redistribution, the stres l mit
in metal c p rts ne d not b satis ed at a sp cif i location if the stres is a self -l mitin
secon ary stres or if it is cau ed by a local stru tural dis ontin ity whic af f ects a relatively
smal volume of material an do s not have a sig if i ant ef f ect on the overal stres or strain
p t ern
Trang 2211 Ne essary exchange of inf ormation
1 1 Inf ormation s ppl e by the apparatus ma uf acturer
When sp cif yin , the purc aser s ould provide as mu h of the f ol owin inf ormation as
neces ary, as wel as an ad itional inf ormation ne ded to determine cle rly the req ired
c) Ap aratu stif f nes
For q alf i ation by calc lation, the stif f nes of the bu hin s p ort (e.g an le of
def lection v b n in moment an the dampin of the stru ture s al b stated If the
stif f nes of the s p ort is so hig an the natural f req en y of the bu hin can b
exp cted to b a ove 8 Hz, it s ould also b stated that the rest of the stru ture down to
the b se is eq al y stif f , otherwise the lower ac eleration at hig f req en ies may not b
uti zed
d) Dy amic analy is
Qual f i ation by d namic analy is is to b made by the man f acturer of the a p ratu
(e.g a tran f ormer) b cau e of the gre t amou t of stru tural data req ired The
a p ratu man f acturer req ests the neces ary data f rom the bu hin man f acturer
1 2 Inf ormation s ppl e by the bus ing ma ufa turer
a) Desig data
In case of d namic analy is of the complete a p ratu , the bu hin man f acturer s ould
provide
– the ge metrical p rameters (i.e dimen ion , centre of gravity, moment of inertia) an
mas es of the complete bu hin , an
– the mec anical pro erties (i.e You g an Pois on ratio or s e r mod lu ,
f lex ral/compres ive/en ie stren th) of the p rcelain an the dampin ratio of the
bu hin , u les stan ard values can b u ed
The a p ratu man f acturer wi p rf orm the d namic analy is an inf orm the bu hin
man f acturer of the res lts to b u ed in the evaluation ac ordin to Clau e 10
b) Seismic q alf i ation re ort
A re ort s owin the res lt of the evaluation p rf ormed ac ordin to clau e 10 The re ort
s ould contain a des ription of the bu hin , the as umption ado ted an the res lts
o tained In the re ort the maximum displacement of the bu hin terminal d rin the
e rth uake s ould b provided
NOT A s e ific tio ma lmit th ma imum p rmis ible d fle tio of th b s in h a u d r th s e ifie
e rth u k c n itio s Howe er, a lmitatio of th d fle tio le d to a c n tru tio with hig er stifn s a d
p s ibly lower d mpin Th t c n c u e hig er stre s s a d, c n e u ntly, lower re ista c a ain t s ismic
lo d This is e p cialy imp rta t for b s in s with c mp site in ulators
c) Test record
If tests are p rf ormed, the re ort s ould contain identif i ation of test o ject, test location,
test eq ipment, des ription of the test, res lts (resonan e f req en ies an dampin ) an
sig if i ant con lu ion
When q al f i ation is p rf ormed ac ordin to 9.4, inf ormation s ould b given in order to
ju tif y that the adeq ac of the bu hin f or a certain grou d ac eleration level is related to
p rtic lar a p ratu d namic p rameter