2004
"HANDS - ON" DEMONSTRATION OF ‘MiCOM P342 & MiCOM343’ NUMERICAL GENERATOR GENERATOR PROTECTION PROTECT ION RELAY RELAY P342 P342 P343 P343
= No dif differen ferenti tial al protect protection ion = With With diff differe erenti ntial al protecti protection on
Objective Objective :- To gain fami familiar liarisation isation of the men men strctre! setting procedres and operation of "i#O" P342 and P343 rela$s%
Intr!#tin t P342 $n! P343 R%$'(
&ach rela$ incldes an e'tensive range of control and data gathering fnctions to provide a completel$ completel$ integrated s$stem of protection! prot ection! control! contr ol! instrmentation! data logging! logging! falt! event and distrbance recording% The rela$s have a ser ( friendl$ displa$ )ith * psh bttons! )hich allo) men navigation and setting changes% +lso! b$ tilising the either the front or rear serial ports of the rela$! fnctions can be read! reset and changed on demand from a local or remote personal compter loaded )ith the "i#O" , soft)are% The P342 and P343 rela$s provide e'tensive protection for generators from a fe) hndred .ilo)atts to t o several hndred mega-)atts% mega-)atts%
1
Intr!#tin)
This demonstration is meant to reinforce the overvie) that has been given previosl$% The intention is that candidates candidates have the opportnit$ opport nit$ to program and ma.e setting changes in the "i#O" rela$s sing the .e$pads and "i#O" , soft)are% /amiliarisation )ith the rela$ protection fnctions )ill also be gained b$ follo)ing the test procedres illstrated in this docment% docment% Pr%*$r$tin 0 #hec. that that the po)er sppl$ is set at the appropriate appropriate a'iliar$ a'iliar$ voltage! see nder nder top flap for a'iliar$ voltage range%
1 Note Note that the relay will will accept a larger range range of voltages0 voltages 0 20 Plg in the serial connection leads bet)een bet)een the compter compter and the pin port on the front of the "i#O" rela$ as sho)n in the diagram belo)%
M i C O M r e lala y
Laptop
2 5 p in d o w n l o a d / m o n i toto r p o r t
Battery
9 pin ror o n t c o m m ! p o r t Serial da ta connector ( up t o 1 5 m )
S e r iai a l c o m m u n i c a tit i o n p o r t (C O M 1 o r C O M 2 )
"010#ena
30 ,)itch ,)itch on on the a'ili a'iliar$ ar$ po)er spp sppl$ l$ The rela$ )ill no) rn throgh a self ( chec. and perform an ,+" chec.% +fter the rela$ has finished its internal chec.s it )ill have the follo)ing message:
escription "i#O" P343
Note that the rela$ sed sed for this e'ercise e'ercise ma$ be a different different model model to the one sho)n above% 5f this is the case the nmber ma$ be different%
2
Frnt *$t% +$,ii$ri($tin) The front plate of the rela$ incldes the follo)ing! as indicated in /igre : 6-character b$ 2-line alphanmeric li7id cr$stal displa$ 18#0 *-.e$ .e$pad comprising 4 arro) .e$s 1 ! ! and 0!an enter .e$ 1 0! a clear .e$ 1 0! and a read .e$ 1 0% 2 8&s9 4 fi'ed fnction 8&s on the left hand side of the front panel and programmable programmable fnction fnction 8&s 8&s on the right hand side% ;atter$ compartment to hold the < ++ sie batter$ )hich is sed for memor$ bac.p for the real time cloc.! event! falt and distrbance distrbance records% + -pin female -t$pe front port for commnicating )ith a P# locall$ to the rela$ 1p to >m distance0 via an &5+1,0232 serial data connection% + 2>-pin female -t$pe port providing internal signal monitoring and high speed local do)nloading of soft)are and langage te't via a parallel data connection% Tri* LED r%!. - This indicates that the rela$ has issed a trip signal% 5t is reset )hen the associated falt record is cleared from the front displa$% 1+lternativel$ the trip 8& can be configred to be self (resetting0?% The trip 8& is initiated from rela$ 3! the protection trip contact% A$r, LED '%/. - /lashes to indicate that the rela$ has registered an alarm% This ma$ be triggered b$ a falt! event or maintenance record% The 8& )ill flash ntil the alarms have been accepted 1read0! after )hich the 8& )ill change to constant illmination! and )ill e'tingish )hen the alarms have been cleared% Ot + (%r0i#% Y%/. Y%/. - indicates the rela$ protection is navailable% H%$t1' Gr%%n. - indicates that the rela$ is in correct )or.ing order! and shold be on at all times% 5t )ill be e'tingished if the rela$@s self-test facilities indicate that there is an error )ith the rela$@s hard)are or soft)are% The state of the health$ 8& is reflected b$ the )atchdog contact at the bac. of the rela$% rela$% S e r i a l 3 o a n d , 4 + a t ini n & !
* o p c o 6 e r
,
LC *+,"
.i7ed unction L!
-L-+M
O%* O. S(+/,C(
0(-L*01
% ! er p r o & r a m a ' l e unction L!
2 CL(-+ 2 +(-) 2 (3*(+
8eypad
Bottom co6er B a tttt e ryr y c o m p a r t m e n t
. ror o n t c o m m ! p o rtr t
o w n lol o a d / m o n iti t o r p o rtr t
Fir% R%$' +rnt 0i%/
"010$3a
M%n n$0i$tin) $
The men is divided into colmns and ro)s to form cells! rather li.e a spreadsheet% &ach cell ma$ contain te't! vales! limits and fnctions% The first cell in each colmn contains a heading! )hich describes the date stored in that colmn% /igre 2 sho)s the strctre of men and indicates indicates )hich )hich .e$s need need to be pressed to traverse it% Fir% 2 M%n (tr#tr% $n! n$0i$tin Sy!tem reuency
O t ; e r d e a u l t d i !p! p l a y !
$:p;a!e 6olta&e - l a rm r m m e ! !a! a & e !
a t e a n d t imi m e
C C
C o lu m n 1 S y t e m d a ta
C o lu m n 2 / i e w r e co r d !
a ta 1 = 1 Lan&ua&e
a ta 2 = 1 La!t record
O t; e r c o lu m n ; e a d i n & !
C o lu m n n
a ta n = 1 > ? 1 u n c titi o n
C 3 o t e A * ; e C e y w i lll l r e tut u r n to c o l u m n ; e a d e r r o m a n y m e n u c e lll l
a tat a 1 = 2 "a!!word
a t a 2 =2= 2 * i m e a n d d a te
O t ; e r ! e t tit i n & c e l l ! inin c o lul u m n 1
O t ; e r ! e tttt i n & cell! in c o lul u m n 2
O t ; e r ! e ttt t inin & cell! in c o lul u m n n
a tat a 1 = n "a!!word le6el 2
a ta 2 = n C @ - 6 o l tat a & e
a ta n = n > ? c ; a r a n & le
a t a n =2= 2 > ? 1 d i rer e c tit i o n a l
"01053a
)5
Ent%r Ent %rin in t1% t1% PASS PASS6O 6ORD RD +r +r, , !%+$ !%+$tt !i(*$ !i(*$'. '.
The rela$ has 3 levels of pass)ord access% The level of access determines )hich operations can be performed and is controlled b$ entr$ of 2 different pass)ords% The levels of access are described belo): +ccess level 8evel A No pass) ss)ord re7ired
Operations enabled ead access to al all setti ttings! alarms! event records and falt records 8evel Pass)ord or 2 re7ired +s level A pls: #ontrol commands! commands! e%g% circit brea.er open B close% eset of falt and alarm conditions% eset 8&Cs% #learing of event and falt records% 8evel 2 Pass)ord 2 re7ired +s level pls: +ll other settings% &ach of the t)o pass)ords are 4 characters of pper case te't% The factor$ defalt for both pass)ords is ++++% ++++% &ach pass)ord is ser-changeable ser-changeable once it has has been correctl$ entered% &ntr$ of the pass)ord is achieved either b$ a prompt )hen a setting change is attempted! or b$ moving to the pass)ord cell in the D,E,T&" +T+F colmn of the men% 4
The rela$ is set )ith a defalt access level of A! sch that the access level 2 pass)ord is re7ired to change an$ of the rela$ settings% 5t is also possible to set the defalt men access level to either level or level 2% The defalt men access level is set in the DPass)ord #ontrolF cell! )hich is also fond in the D,E,T&" +T+F colmn of the men 1note that this setting can onl$ be changed )hen level 2 access is enabled0% The crrent level of access can be determined b$ e'amining the D+ccess 8evelF cell or as one of the defalt displa$ options% &ntering the pass)ord and changing the access level :$. /rom the defalt displa$ press to displa$ SYSTEM DATA ntil P$((/r! is displa$ed% 7. Geep pressing follo)ed follo)ed b$ to enter the pass)ord #. Press 1++++0 ntil the P$((/r! Cntr cell is displa$ed% !. With the pass)ord entered press %. Press ! follo)ed b$ to give a defalt access level of 2%
The rela$ is no) at access level 2 allo)ing an$ setting to be changed% The pass)ord no longer needs to be entered ntil the rela$ is retrned to access level A or b$ sing the P$((/r! Cntr cell% 2)5
T%(tin %(tin t1% 7i$( 7i$(%! %! !i++ !i++%r %r%n %nti$ ti$ %%, %%,%n %nt) t)
/ailre of stator )indings! or connection inslation! can reslt in severe damage to the )indings and the stator core% /or primar$ generating plant! )here falt levels can be large in magnitde! high speed disconnection of the plant from the po)er s$stem ma$ also be necessar$ to maintain s$stem stabilit$% /or generators above "H+! it is common to appl$ generator differential differential protection% This form a protection protec tion provides fast detection of internal falts )hilst giving high stabilit$ for e'ternal falts% The P343 provides 3 forms of generator differential protection:
;iased Iigh impedance 5ntertrn
We )ill be testing the biased differential element as it is the most comple' of the three% /or more information on differential protection! inclding high impedance and intertrn protection! conslt the application application gide of of the P343 technical technical manal% manal% The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JOK JOKP P J& J&N 5 5// "&+, "&+,K K&" &"&N &NT, T, 3
1&nabling DJ&N 5//F fnction0 1Pro 1Prote tect ctio ion n set setti tin ngs for for differe ferent ntiial ele element0 1Obs 1Obser erva vati tion on of bias ias and and dif differe ferent ntia iall crr crren ents ts00
a0 8ocate ate the CONFIGURATION colmn and then enable DG%n Di++%r%nti$8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP GEN DIFF colmn and then appl$ the follo)ing settings:
Jeniff /nction Percentage ;ias Jen iff 5s 5
AA m+ Jeniff . AL Jen iff 5s2 %2AA + Jen iff .2 >A L The operation of differential trip signals can be sho)n in the Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells 1iff Trip + - ;4! iff Trip ; - ;42A! iff Trip # - ;42! iff Trip - ;40% c0 #onnect #onnect the circit circit as sho)n sho)n in in the the /igre /igre 3 belo) belo)%%
I1 I1 C3 IA IA C2 P343
I2 I2
E3 IA IA2 E2
Fir% 3 Cnn%#tin !i$r$, +r 7i$(%! !i++%r%nti$ t%(t
d0 ,lo)l$ increase the crrent 5 ntil the rela$ operates )hilst leaving leaving 52 at A +mps% +mps% ecord the operating opera ting crrent 5 in the table provided% We have no) no ) assessed ass essed the t he minimm sensitivit$ of the rela$% This gives an indication of the crrent re7ired to case operating for a genine genine internal falt% falt% Notice that the rela$ does not operate at e'actl$ the 5s setting bt at a vale slightl$ higher% This is de to a small amont of bias being generated b$ the 5 crrent! )hich inevitabl$ raises the rela$ setting% The actal minimm sensitivit$ is given b$ the follo)ing e7ation :"inimm Pic.-p crrent =
.- 5s2
.-
5s-
The ne't phase of testing a bias differential rela$ is to establish that the bias characteristic matches the rela$ settings% This is done b$ adjsting the magnitde of the t)o anti-phase crrents 15 and 520 ntil the rela$ operates% +t the point of opera tion the differential differential and bias crrents can be calclated calclated and plotted to see if the$ correlate )ith the rela$ settings% settings% This test is e'plained belo)% e0 +ppl$ the initial initial crrents stated in the table table and then then slo)l$ slo)l$ increase crrent 5 ntil ntil the rela$ operates% Not Notee the crrent at )hich the rela$ operates 1in D5 TripF colmn0! colmn0! calclate the bias and differential crrents and then plot them on the graph provided% C
Note that the per phase bias and differentia differentiall crrent can be observed observed in the "&+,K&"&NT, 3 colmn% 5nitial 5
52
A A%3 AD A%6 AD %2 AD %4 AD %> AD
A A%3 AD A%6 AD %2 AD %4 AD %> AD
5 Trip
A%4 A%* %6 3 3%*
;ias #rrent = 15 Trip M 520B2
ifferential #rrent = 5 Trip ( 52
A%3> A%6> %4 2%2 2%6
A% A% A%4 %6 2%2
/or the lo)er bias slope the formla belo) can be sed to determine the differential operate crrent c rrent 1enter . slope in p p form! i%e% percentageBAA0: phase operate crrent is 15s M 5;ias ' .0 p MB- AL /or the pper bias slope the formla belo) can be sed to determine the differential operate crrent c rrent 1enter . and .2 slopes in p form! i%e% percentageBAA0: Operate crrent is 15;ias ' .20 M 1. ( .20 ' 5s2 M 5sQ p MB- 2AL
3.5
3 . ( 2.5 * , A t 2 n % r r " C1.5 & $ i t n % r 1 % + + i D 0.5
Expected Characteristic
0 0
0.5
1
1.5
2
2.5
3
3.5
9i$( C"rr%nt C"rr%nt -A,*(. -A,*(.
5f the test has been performed correctl$ the recorded reslts shold closel$ match match those sho)n above% The plot clearl$ sho)s that the rela$ increases increases it setting as the throgh falt crrent increases! ths minimising the chances of mal-operation de to #T satration% Iad )e tested the high impedance or intertrn differential then )e )old see that the setting does not increase )ith throgh falt crrent% This is becase high high impedance protection relies pon an e'ternal resistor for stabilit$ rather than bias% The intertrn differential is normall$ connected via core balance #T@s )hich are not ssceptible to satration affects )hich case problems )ith the high impedance or percentage bias schemes% schemes% 3)5
T%(tin %(tin t1% t1% 3 *1$( *1$(%% */%r */%r *rt% *rt%#t #tin in))
The P342 and P343 have three forms of of 3 phase po)er protection! protecti on! these are :#
everse 8o) for)ard Over po)er
We )ill be testing the reverse po)er and lo) for)ard po)er protection featres% The over po)er protection is tested in similar )a$ to the reverse po)er )hich is )h$ it has been omitted omitted from these test instrctions% The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JOKP POW& "&+,K&"&NT, 2
1&nabling DPo)erF f fnction0 1Protection settings fo for po)er pr protection0 1Ob 1Observati ation of of th the th three ree ph phase po)er0
R%0%r(% P/%r Prt%#tin
a0 8ocate ate the CONFIGURATION colmn and then enable DP/%r8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP PO6ER colmn colmn and then appl$ the follo)ing settings: Operating "ode Jenerating Po)er /nction everse -PR ,etting 3A%A W Po)er Time ela$ As
E
Po)er O Timer As P Poledead 5nh &nabled Po)er2 /nction isabled f0 The operation operation of po)er po)er startBtrip signal signalss can be be sho)n sho)n in the the Test Test Port ,tats cell in in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells 1Po)er Trip - ;4*>! Po)er 2 Trip - ;4*6! Po)er ,tart ( ;>>! Po)er 2 ,tart ( ;>60% c0 #onnect #onnect the circ circit it as sho)n sho)n in the /ig /igre re 4%
IA IA I' I' IC IC N
C3
P343 IA IA
C2 C)
I' I' C5 C,
IC IC
Test &et C+
%A
C1,
%A
%' %C N
C20
%' C21
C22
%C
(5
Timer &top
()
*e$a3
NOTE C : onnectionsma!ar"et#eenmode$s
Fir% 4 Cnn%#tin !i$r$, +r 3 *1$(% */%r t%(t(
d0 +ppl$ +ppl$ the follo) follo)ing ing voltages: voltages: Ha Ha = >AH AS! Hb = >AH -2AS! Hc = >AH2AS e0 +ppl$ +ppl$ the follo follo)in )ing g crrents: crrents: 5a = A%+AS! 5b = A%+6AS! 5c = A%+-6AS% This represents a reverse po)er of >W 1A% ' >A ' 30% g0 5ncrease 5ncrease all three three crrents ntil ntil the the rela$ operates% operates% Operation Operation shold shold occr occr at appro'imatel$ A%2+! )hich is e7ivalent to the 3AW setting 1A%2 ' >A ' 30% Note that the setting is a 3 phase po)er 7antit$% 7antit$% Note the 3 Phase po)er measrement measrement can be observed in the "&+,K&"&NT, 2 colmn% f0 This This test has has proved proved the reverse reverse po)er po)er threshold threshold is correct% The The ne't ne't step is to establish that the characteristic is a s$mmetrical% 9
g0 isconnect isconnect the timer stop leads leads from the the rela$ then appl$ appl$ the same voltages! voltages! )ith the follo)ing crrents: 5a = +AS! 5b = +6AS! 5c = +-6AS% Note that the rela$ operates strongl$ as the po)er 1>AW0 is )ell )ithin )ithin the operating region of the characteristic% h0 otate the phase angle angle of the three crrents cloc.)ise! cloc.)ise! maintain maintaining ing their 2AS 2AS phase relationship! ntil the rela$ stops operating% This is indicated b$ the D+n$ ,tartF 8& s)itching s)itching off 18& 0% eset the trip indications indications and then rotate bac. in to the characteristic ntil the rela$ operates once again% Note this angle do)n% i0 epeat epeat section DhF DhF e'cept e'cept rotate anti-cloc.) anti-cloc.)ise ise this this time% time% Once again again note the angle% angle% The measred angle shold be e7al indicating the characteristic is s$mmetrical! as sho)n in the /igre >% % %Ar
15 150%A
T*IP
*E&T*AIN
/ /
T*IP
Po#er &ettiin-
*E&T*AIN
15 15/
.% .%Ar
Fir% : R%0%r(% */%r #1$r$#t%ri(ti#
,electing D"otoringF in the DOperating modeF cell inverts the active po)er measrement% measrement% This effectivel effectivel$ $ reverses the po)er characteristic so that it )old appear on the DMWF side% The ne't step is test the DPo)er O timerF% This stops the DPo)er Time ela$F timer from resetting if the po)er momentaril$ e'its the characteristic% /lctating po)er is common common )ith diesel engines engines prime prime mover failr failres% es% ;$ setting a time dela$ dela$ on on reset the rela$ ma$ still operate even if the po)er flctations are severe% j0 "odif$ the follo)ing follo)ing settings: Po)er Time ela$ A s Po)er O Timer A s .0 e-connect the timer timer stop leads to the rela$ then appl$ appl$ the the follo)ing follo)ing voltages: Ha Ha = >AHAS! Hb = >AH -2AS! Hc = >AH2AS l0 +ppl$ +ppl$ the follo) follo)ing ing crrents crrents and chec. chec. that the rela$ rela$ operates operates in A second seconds: s: 5a = A%>+AS! 5b = A%>+ 6AS! 5c = A%>+-6AS% m0 ,)itch off off the crrent for at least 2 seconds seconds and then re-appl$ the falt% Note that the rela$ )ill once again operate in A seconds% This proves that the DPo)er Time ela$F 10
is correct and that the rela$ is fll$ resetting follo)ing the DPo)er O TimerF% /igre 6a sho)s the operation opera tion of the rela$ nder this condition% condition% The ne't stage is to prove that the rela$s operating level level is held held for the DPo)er O TimeF% This is done b$ appl$ing a reverse po)er condition for! sa$! > seconds follo)ed b$ a for)ard po)er condition for 2 seconds seconds and then a reverse po)er condition condition once again% 5f the rela$ operate level is held correctl$! )hen the falt is re-applied the operating time )ill be shorter% 5n theor$ the operating time shold be e7al to the DPo)er Time ela$F setting mins the dration of the first falt application% Io)ever! in practice the operating time ma$ be even shorter shorter as most test sets ta.e a finite finite length of time time to move from a for)ard po)er condition to reverse po)er condition and bac. again% This means that the rela$ ma$ be in the reverse po)er condition longer than e'pected% /igre 6b illstrates the rela$ behavior for these falt conditions%
Trip
Trip resho$d a a$ton
,tead$ reverse po)er condition
a0 OpTime1 e10s
Trip
Trip resho$d a a$ton
a a$ton
/lctating reverse po)er condition
b0 5s 5s
5s 5s 2s 2s
Fir% ; A**i#$tin + +#t$tin r%0%r(% */%r
n0 +ppl$ the follo)in follo)ing g crrents for appro'imatel appro'imatel$ $ > seconds: A%>+AS! 5b = A%>+6AS! 5c = A%>+-6AS% Then rotate the crrents b$ AS AS for roghl$ 2 seconds and then retrn them% The rela$ operating time shold be less than > seconds once the falt is re-applied! indicating the rela$ has pased the operation timer instead of resetting it% L/ Fr/$r! P/%r Prt%#tin
When a machine is generating and the #; connecting the generator to the s$stem is tripped! the electrical load is ct% This cold lead to the generator over-speed if the mechanical po)er is not redced 7ic.l$% When non-rgent falts occr! sch as a stator earth falt on a high impedance earthed machine! it ma$ be prdent to disconnect the prime mover mover before before opening this #;% Trippin Tripping g of the circit circit brea.er occrs )hen the otpt po)er has fallen to sfficient levels so as to minimise the possibilit$ of overspeed% This process is .no) as lo) for)ard po)er interloc.ing% The follo)ing section is a simple demonstration of this featre% 11
o0 "odif$ "odif$ the fol follo) lo)ing ing settings: settings: Po)er /nction 8o) /or)ard P ,etting 2 W Po)er Time ela$ As Po)er O Timer As p0 +ppl$ the follo)ing follo)ing voltages: Ha Ha = >AH AS! Hb = >AH -2AS! Hc = >AH2AS 70 +ppl$ +ppl$ the follo follo)in )ing g crrent: crrent: 5a = A%2+ A%2+AS! 5b = A%2+ -2AS! 5c = A%2+2AS% This represents a for)ard f or)ard po)er of 3AW% 3AW% r0 ,lo)l$ ,lo)l$ decrease decrease the crrent crrent ntil ntil the rela$ rela$ operates% operates% Operation Operation shold shold occr occr at appro'imatel$ at A%A+% This corresponds to a 3 phase for)ard po)er of 2W% 4)5 4)5
Fi% Fi%! ! +$i +$ir r%% *rt *rt%# %#ti tin n))
#omplete loss of e'citation ma$ arise as a reslt of accidental tripping of the e'citation s$stem or even open circit or short circit falts occrring the # s$stem% 8oss of the e'citation cases the internal emf emf to collapse c ollapse and and the redction of active po)er otpt% Knder this condition the generator can over-speed and dra) rea ctive po)er from the s$stem% The difference in speed bet)een the rotor and the s$stem cases lo) fre7enc$ crrents to flo) in the rotor circit! )hich ma$ reslt in damage to the machine depending pon its constrction% The P342 and P343 tilises a mho characteristic to detect this condition and disconnect the machine if appropriate% We )ill be testing the field failre alarm and the first stage of the field failre characteristic% This is sho)n in /igre * belo) :
* * A$a A$armAn-$e
a1
a1 "1 A$ar $armAn-$e
20oh 0ohms 220oh 0ohms 156
"1
c c
Fir% < Fi%! +$ir% #1$r$#t%ri(ti#
The follo)ing headings )ill be sed to perform this tas. :12
#ON/5JK+T5ON 1&nabling D/ield /ailreF fnction0 JOKP /5&8 /+58K& /+58K& 1Protection settings for field field failr failre0 e0 a0 8ocate ate the CONFIGURATION colmn and then enable DFi%! F$ir%8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP FIELD FAIL colmn and then appl$ the follo)ing settings: //ail +lm +lm ,tats ,tat s &nabled //ail +lm +ngle >%A deg //ail +lm ela$ As //ail ,tats &nabled //ail (Ua 2A Ohm //ail Ub 22A Ohm //ail Time ela$ As //ail O Timer As //ail2 ,tats isabled The operation of /ield /ailre alarmBstartBtrip signals can be sho)n in the Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells 1//ail Trip - ;422! //ail 2 Trip ;423! //ail ,tart ( ;63*! //ail 2 ,tart ( ;63! /ield /ail +larm ( ;3A0% The first part of the test is prove the operating bondar$ of the field failre alarm: c0 +ppl$ +ppl$ the follo) follo)ing ing voltage voltage and crrent: crrent: Ha Ha = AAH AS! 5a = %A+AS% d0 otate the crrent 1crrent leads volts0 volts0 ntil the rela$ displa$ displa$ the D//ail D//ail +larmF +larmF on the 8# accompanied b$ the $ello) alarm 8&% This shold occr at roghl$ M>S% e0 otate the crrent crrent in the opposite opposite directio direction n 1noting 1noting that alarm alarm resets0! resets0! ntil ntil the alarm alarm operates once again% Operation shold occr at roghl$ r oghl$ 6>S% We )ill no) prove the field failre characteristic:
f0 isable isable the field field failr failree alarm b$ modif$i modif$ing ng the follo)ing follo)ing setting setting as follo)s follo)s ://ail +lm +lm ,tats ,tat s isabled 1$
g0 +ppl$ +ppl$ the follo) follo)ing ing voltage voltage and crrent: crrent: Ha Ha = AAH AS! 5a = A%2>+ MAS% The applied impedance is at position D+F of the polar diagram in /igre % h0 5ncrease the crrent ntil ntil the rela$ operates% This shold occr at roghl$ A%42+ 1AAHB122AM2A00 and indicates indicates that )e are no) at the oter edge of the circle ( point D;F 1UaMUb0% i0 5ncrease 5ncrease the crrent crrent to A%>+% The The rela$ rela$ shold shold be operatin operating g strongl$ strongl$ as the rela$ rela$ impedance is no) at point #% j0 otate the phase angle of the crrent anti-cloc.)ise anti-cloc.)ise ntil ntil the rela$ rela$ drops off off and it is possible possible to reset it% ,lo)l$ rotate the crrent phase angle cloc.)ise cloc.)ise ntil ntil the rela$ rela$ jst jst operates again% ecord the phase angle bet)een the crrent and voltage 1 on the polar diagram0% diagram0% .0 Withot changing changing the magnitde magnitde of the crrent and voltage! rotate the crrent phase phase angle cloc.)ise! passing throgh the operating area! ntil once again it is possible to reset the rela$% ,lo)l$ rotate the crrent phase angle anti-cloc.)ise ntil the rela$ again jst jst operates% operates % "easre the ne) angle! 2 on the polar diagram% The rela$ characteristic angle is the mean of the t)o measred angles and shold be roghl$ AS% l0 +ppl$ +ppl$ the follo follo)in )ing g voltag voltagee and crrent: crrent: Ha = AHAS! 5a = %A+ MAS% The applied impedance is at position DF of the polar diagram% m0 ,lo)l$ increase the voltage ntil ntil the rela$ again again jst operates% This shold shold occr at 2AH 12AohmB+mp0% The rela$ impedance is no) at point D&F! ths proving that the characteristic has the ccorrect orrect dimension dimensionss and position%
.* .*
* * 7 E
C 1
C
C2
' A
c Fir% = P$r !i$r$, + +i%! +$ir% #1$r$#t%ri(ti# 14
:)5 :)5
T1%r T1 %r,$ ,$ 0%r 0%r $! $! *r *rt%# t%#ti tin n))
Overloads can reslt in stator temperatre te mperatre rises that e'ceed the thermal limit limit of the )inding inslation% &mpirical reslts have sho)n that the life of the inslation is halved for each AS# rise in temperatre above the rate d vale% Io)ever! the life of the inslation is not )holl$ dependent pon the rise in temperatre bt on the time the inslation maintained at this elevated temperatre% This means that short overloads ma$ case little damage to the machine )hereas sstained overloads ma$ case e'tensive damage to the )indings and inslation% Knbalanced load )ill also give rise to rotor heating de to the negative se7ence se7ence created% The P343 rela$ models the time-crrent thermal characteristic of a generator b$ internall$ generating a thermal replica of the machine% ;oth the positive and negative se7ence crrents are combi c ombined ned together to form an e7ivalent e7ivalent crrent 15e70% We )ill be testing the thermal characteristic )ith both positive and negative se7ence crrents% The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JO JOKP TI& I&"+8 OH& H&8O+ 8O+ "&+,K"&NT, 3
1&nabling DThermal OverloadF fnction0 1Pro 1Prote tect ctio ion n sett settiings for for ther therm mal0 al0 1Observation of thermal state0
a0 8ocate ate the CONFIGURATION colmn and then enable DT1%r,$ O0%r$!8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP THERMAL O>ERLOAD colmn and then appl$ the follo)ing settings: Thermal &nabled Thermal 5R %A+ Thermal +larm AL T-heating %A min T-cooling %A min " /actor 3
15
The operation of Thermal alarmBtrip signals can be sho)n in the Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells 1Thermal OB8 Trip ( ;4! Thermal +larm ( ;3A*0% c0 #onnect #onnect the circ circit it as sho)n sho)n in the /ig /igre re %
C3
IA IA
IA IA
I' I'
Test &et
P343
C2 C)
IC IC
I' I'
N
C5 C,
IC IC C+
Fir% ? Cnn%#tin !i$r$, +r t1%r,$ t%(t(
d0 8ocate ate th the MEASUREMENTS 3 colmn and then scroll do)n to displa$ the DThermal OverloadF measrement% e0 +ppl$ +ppl$ the follo follo)in )ing g crrents crrents to the rela$ rela$:: 5a = %A+ %A+AS! 5b = %A+-2AS! 5c = %A+2AS% Notice that the rela$ thermal measrement measrement reaches roghl$ 63%2L after minte 1 time constant0 and 6%>L after 2 12 time constants0 mintes this time% This proves that the rela$ is correctl$ modellin modelling g the e'ponential e'ponential temperatre rise of the protected plant 1cable! 1cable! transformer etc%0% ,)itch the crrent off after after 2 mintes% Iad )e injected crrent for > mintes the rela$ thermal level )old have reached AAL and eventall$ tripped% f0 8ocate 8ocate the Dese Desett Therm Thermal alOB OB8F 8F cell cell in the MEASUREMENTS 3 colmn and then select $es to reset% Notice that the thermal level level has reset to AL% The ne't step is to establish the rela$ operating time for an overload condition% g0 +ppl$ +ppl$ the follo) follo)ing ing crrents crrents and )ait for for the rela$ to trip: 5a = 2%A+ AS! 5b = 2%A+2AS! 5c = 2%A+2AS% The rela$ shold trip and displa$ a thermal trip in appro'imatel$ *%3 seconds% The rela$ operating time is given b$ the follo)ing e7ation :-
5e72 5p top V 8oge 2 5e7 Where: 2
5e7
=
5-
2
M52
Thermal 5
1C
Prefalt load
5p
=
5 52 " Therm ermal 5R
Thermal 5
= Positive se7ence crrent = Negative se7ence crrent = Negative se7ence mltiplier = Ther Therm mal ,etti etting ng = heating time constant in seconds
Therefore )ith no negative se7ence: 5e7
=
22 3 A2 -=A
= 2+
With no pre falt crrent the operating time 1top0 is calclated calclated as follo)s :-
2 2 A = *%26 seconds 2 2
top 6A 8og e
No) that )e have proved the rela$ operating time! the the ne't step is to prove the cooling time constant% This is done as follo)s:h0 8ocate the the Deset Deset Therma ThermalOB lOB8F 8F cell cell in the MEASUREMENTS 3 colmn and then select $es to reset% i0 +ppl$ +ppl$ the follo follo)in )ing g crrents crrents and and )ait for for the rela$ rela$ to trip: 5a = 2%A+AS! 5b = 2%A+2AS! 5c = 2%A+2AS% Once again the rela$ shold trip in appro'imatel$ *%3 seconds% &nsre that the crrent is s)itched off off as soon as the rela$ trips% j0 Wait for one DcoolingF DcoolingF time constant! also 6A seconds! and then re-appl$ the the same crrent to the rela$% Notice that the rela$ operating time is roghl$ seconds 163%2L of *%26 seconds0% The redced operating time is de to the thermal level not reaching ero before the falt is re-applied% /igre A illstrates this behavior% 120 a$t reapp$ied. Trip time 10.,s 100 *e$a therma$ state
. +0 @ % t $ t S )0 & $ , r % 1 40 T Initia$ 9a$t app$ication 18.2)s
20
No 9a$t 9a$t app$ied. )0s econd coo$in- period. 0 0
10
20
30
40
50
)0
80
+0
,0
100
Ti,% -(%#n!(. 1#
Fir% 5 R%$' t1%r,$ (t$t% +r int%r,itt%nt +$t(
.0 8ocate the the Deset Deset Therma ThermalOB lOB8F 8F cell cell in the MEASUREMENTS 3 colmn and then select $es to reset% We )ill no) test the rela$s behavior )hen negative se7ence is applied instead of positive se7ence :l0 +ppl$ +ppl$ the follo follo)in )ing g crrents crrents and and )ait for for the rela$ rela$ to trip: 5a = 2%A+AS! 5b = 2%A+2AS! 5c = 2%A+-2AS% The injected crrents represent re present 2+ of pre negative se7ence% The rela$ shold trip and displa$ a thermal trip in appro'imatel$ >%22 seconds% The rela$ operating time is given b$ the follo)ing e7ation :Therefore )ith no negative se7ence: 5e7
=
A2 3 2 2 -=A
= 3%46+
With no pre falt crrent the operating time 1top0 is calclated calclated as follo)s :-
3=46 2 A = >%22 seconds 2 = 3 46
top 6A 8og e
Notice that the rela$ operating time time is signif significan icantl$ tl$ redced )hen negative negative se7ence se7ence is applied% This is de to the D" /actorF )hich increases the effect of negative se7ence% ;)5 ;)5
O0%r O0%r+ + in in *rt *rt%# %#ti tin n))
Overfl'in Overfl'ing g or overe'citation of a generator! or transformer connected to the terminals of a generator! can occr if the ratio of voltage to fre7enc$ e'ceeds certain limits% Iigh voltage or lo) fre7enc$! casing a rise in the HBI ratio! )ill prodce high fl' densities in the core of the machine or transformer% This cold case the core of the generator or transformer to satrate satra te and stra$ fl' to be indced indced in components components that have not been designed to carr$ fl'% The reslting edd$ crrents ma$ case overheating and damage% The P342BP343 provides a t)o stage overfl'ing element% The element measres the ratio of H+; voltage! to fre7enc$% The rela$ )ill operate )hen the HBI ratio e'ceeds the setting% One stage can be set to operate )ith a definite time or inverse time dela$! this stage can be sed to provide a protection trip% The other stage s tage can be sed as a definite time alarm% We )ill be testing the HBI protection element )ith a definite time dela$ and an inverse time dela$% The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JOKP HO8T,BI
1&nabling DHBIF fnction0 1Protection settings for HBI protection0
1E
a0 8ocate ate the CONFIGURATION colmn and then enable D>BH8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP >OLTSBH >OLTSBH colmn and then appl$ the follo)ing settings: +lm ,tats isabled Trip /nc T Trip ,et 2%2 HBI Trip ela$ As c0 +ppl$ +ppl$ the follo follo)in )ing g voltage voltages: s: Ha Ha = >AHAS! Hb = >AH -2AS! Hc = >AH2AS% These voltages mst be applied at >AI% &nsre that the timer stop leads are disconnected% d0 5ncrease all three voltages ntil the rela$ operates and displa$s displa$s HBI trip% Operation shold occr at appro'imatel$ 63%>H 1AHB 30 as the rela$ is measring a phase to phase voltage% e0 etrn all three voltages voltages to >AH and and then then reset the the rela$ rela$% f0 ,lo)l$ redce the fre7enc$ fre7enc$ ntil the rela$ operates once again% again% Operation Operation shold shold occr at appro'imatel$ appro'imatel$ 3I 1AHB1B3 ' 2%200% g0 etrn the the fre7en fre7enc$ c$ to to >AI and then then reset reset the rela$% rela$% We have so far tested test ed that the HBI threshold responds to changes in both voltage and fre7enc$ fre7enc$% The ne't step is to prove that the 5"T characteristic is correct% correct % h0 "odif$ "odif$ the fol follo) lo)ing ing settings: settings: Trip /nc 5"T Trip ,et 2%2 HBI Trip T", %AAA The operation of Overfl'ing alarmBstartBtrip signals can be sho)n in the Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells cells 1HBI Trip - ;42! HBI ,tart ( ;636! HBI +larm ( ;3A0% i0 econnect econnect the the timer stop leads leads then then appl$ appl$ the the follo)i follo)ing ng voltag voltagee 1at >AI0: Ha Ha = *AHAS! Hb = *AH -2AS! Hc = *AH2AS% This corresponds to a vale of 2%42HBI! )hich e7ates to % 1"0 times the setting% Therefore the operating time shold be: Operating time =
A%:
A%-: T",
" -
2
A%:
A%-: -
-=- -
2
-:%: seconds
19
To ensre the characteristic is correct it is prdent to chec. at least one more point on the crve: j0 eset the rela$ then appl$ Ha = *6HAS! Hb = *6H -2AS! Hc = *6H2AS% This e7ates to roghl$ %2 %2 times the setting! ths giving an operating time of >%3 seconds% <)5
55@ 55@ St$t St$tr r %$rt %$rt1 1 +$ +$t t *rt% *rt%#ti #tin) n)
,tandard residal crrent or voltage protection elements can onl$ protect >L of the stator )inding% &arth falts in the final >L of the )inding )ill reslt in sch lo) falt crrent and voltage imbalance imbalance that conventional conventional protection cannot be relied pon to detect the falt% The P343 provides emplo$s a techni7e )hereb$ the rela$ loo.s for changes in the amont of third harmonic being prodced b$ the generator% Knder normal conditions the third harmonic voltage is distribted evenl$ along the stator )inding% ring an earth falt the in the final >L of the )inding the third harmonic voltage )ill rise significantl$ at the generator terminals% terminals% 5f the HT )ere connected at a t the generator termina t erminals ls the third harmonic voltage rise cold be detected% Io)ever! if the voltage from a netral earthing HT )ere applied to the rela$ then this )old see the third harmonic voltage collapse% Therefore the rela$ has t)o settings! set tings! these are overvoltage mode for a terminal HT and and ndervoltage mode for a netral earthing HT% /or more information information on AAL stator earth falt protection refer to that application gide of the P342BP343 manal% We )ill be testing the AAL stator earth falt protection in both overvoltage and ndervoltage modes: The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JOK JOKP P AA AAL L ,T ,T+TO &/
1&nabling DAAL ,tator &/ &/F fnction0 1Pro 1Prote tect ctio ion n set setti tin ngs fo for A AAL stat stator or &/ &/0
a0 8ocate ate the CONFIGURATION colmn and then enable D55@ St$tr EF8 % &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP 55@ STATOR EF colmn and then appl$ the follo)ing settings: AAL ,t &/ ,tats HN3IR &nabled AAL ,t &/ HN3IR 2AH HN3IR ela$ As The operation of AAL ,tator &/ startBtrip startBt rip signals can be sho)n in the Test Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells cells 1AAL ,T &/ Trip - ;46! AAL ,T &/ ,tart ( ;620% c0 #onnect #onnect the circi circitt as sho)n sho)n in in the the /igre /igre % %
20
%ariac C1,
24 240% 0( 0(;<
%A
%1 C20
%' P343
C21
F C22 C23
%A
Test &et 1 150(;<
%C
C24
%N
%N
Fir% Cnn%#tin !i$r$, +r 55@ (t$tr EF t%(t(
d0 Ksing the tests set appl$ >H at >AI% ,lo)l$ ,lo)l$ increase the voltage ntil ntil the rela$ rela$ operates and indicates indicates a AAL stator &/ trip% Operation shold occr at a t 2AH% 2AH% e0 edce edce the the voltage voltage to >H the reset reset the rela$ rela$% This proves that the rela$ r ela$ )ill )ill operate if the HT is connected on the generator terminals% terminals% The ne't stage is to chec. operation if a netral earthing HT )as sed% This is done b$ selecting the element to be ndervoltage instead of overvoltage% 5t is also necessar$ to appl$ a voltage to the normal voltage voltage inpts so that the rela$ assmes the generator is energised% emember that a redction in 3 rd harmonic ma$ be de to the generator being de-energised instead instead of an actal earth falt% .0 "odif$ "odif$ the fol follo) lo)ing ing settings: settings: AAL ,t &/ ,tats HN3I &nabled AAL ,t &/ HN3IR %AAAH H 5nhibit ,et A H P 5nhibit isabled X 5nhibit isabled , 5nhibit isabled f0 Ksing Ksing the tests tests set app appl$ l$ >H at >AI >AI%% g0 Ksing the variac variac appl$ appl$ AH to the phase voltage terminal terminals% s%
21
h0 ,lo)l$ ,lo)l$ decrease decrease the voltage voltage on the test set 1>AI0 ntil ntil the rela$ rela$ operates% operates% This This rd shold occr a roghl$ volt and proves the 3 harmonic ndervoltage is )or.ing correctl$% i0 ,)itch off off the variac and chec. chec. that it is possible possible to reset the rela$ rela$% This This ensres that the nder voltage inhibit featre is correctl$ fnctioning% Knfortnatel$ de to limitations in the test e7ipment it is impossible for s to test the nder po)er inhibits inhibits on the AAL stator earth falt protection% The nder po)er inhibits )o. in e'actl$ the same )a$ as the nder voltage inhibit e'cept that there needs to be a certain amont of Watts! H+ and H+r@s flo)ing before the protection is enabled%
=)5 =)5
P% P% (i* (i**i *in n *rt *rt%# %#ti tin n))
,dden changes or shoc.s in the electrical po)er s$stem sch as line s)itching operations! large jmps in load or falts ma$ lead to s$stem oscillations )hich appear as reglar variations of the crrents! voltages and anglar separation bet)een s$stems% This This phenomenon phenomenon is referred to as a po)er s)ing s )ing%% 5n a recoverable sitation! the po)er s)ing )ill deca$ and finall$ disappear in a fe) seconds% ,$nchronism )ill be regained and the po)er s$stem )ill recover to stable operation% 5n a non-recoverable sitation! sitation! the po)er s)ing becomes becomes so severe that s$nchronism is lost bet)een the generator and the s$stem% 5f sch a loss of s$nchronism does occr it is imperative to separate the generator from the rest of the s$stem before damage occrs% The P343 provides a lenticlar impedance characteristic )hich is sed to detect pole slips% slips% 5f rela$ detects the s$stem impedance impedance passing throgh the characteristic at a certain speed and direction then a trip )ill be given% The fll criteria for operation is as follo)s:Jenerating mode 1machine acting as a generator0: Pole slip mode mst be set to DgeneratingF% DgeneratingF% 5mpedance starting from point enters characteristic and sta$s roghl$ at 2 for at time greater than the DP,lip Timer TF and then enters 3% The impedance mst sta$ arond 3 for at least the DP,lip Timer T2F before e'iting e'iting in in to 4% 5f this se7ence se7ence is not not follo)ed or each region region is e'ited e'ited before the timers e'pire then rela$ )ill not trip% "otoring mode 1machine acting as a motor0: Pole slip mode mode mst be set to DmotoringF% 5mpedance 5mpedance starting from point 4 enters characteristic and sta$s roghl$ at 3 for at time greater than the DP,lip Timer TF and then enters 2% The impedance mst sta$ arond 2 for at least the DP,lip Timer T2F before e'iting e'iting in in to % 5f this se7ence se7ence is not not follo)ed or if the impedance impedance e'its e'its each region before the timers e'pire then rela$ )ill not trip% ;oth generating and motoring 1machines 1machines can operate as generator or motor0 Pole slip mode mode mst be set to DmotoringF% Operation can occr in either the generating or motoring se7ences are follo)ed% 22
The regions to 4 are sho)n in figre 2 together )ith an illstration of the rela$ settings% We )ill be proving the characteristic shape as )ell as the rela$ abilit$ to detect a genine pole slip slip condition% condition% The follo)ing headings )ill be sed to perform this tas. :#ON/5JK+T5ON JOKP PO PO8& ,8 ,85PP 5PP5NJ
1&nabling DPole ,lippingF fnction0 1Prot Proteecti ction set setttings fo for po pole sl slipping0
2$
=o =one2 =A =A100oh 0ohms
=o =one2
* e c a a c t t n n c c e e $ i n e e
= C 3 5 0 0 o h s m
85 856
.* .*
*
*4
12 1206
*3
r e d n i $ '
*2 *1
on one1> e1> on one2 =one1> e1> =one2
=' ='1150oh 0ohms
c c
Fir% P% (i* #1$r$#t%ri(ti#
a0 8ocate ate the CONFIGURATION colmn and then enable DP% Si**in8% &nsre that all other protection fnctions are disabled in this colmn% b0 8ocate the GROUP POLE SLIPPING colmn and then appl$ the follo)ing settings: P,lip /nction &nabled Pole ,lip "ode Jenerator P,lip a /or)ard AA Ohms P,lip a /or)ard >A Ohms 8ens +ngle 2A deg P,lip Timer T >%AA ms P,lip Timer T2 >%AA ms ;linder +ngle *> deg 24
P,lip c >A Ohms one ,lip #ont one 2 ,lip #ont 2 P,lip eset Time 3A%AA s We )ill no) prove the shape of the characteristic before )e test tes t its abilit$ abilit$ to detect pole slips% slips% c0 #onnect #onnect the circ circit it as sho)n sho)n in the /ig /igre re 4% d0 "odif$ the P,8 so that the 8& mappings mappings are as sho)n in in /igre /igre 2% &ach &ach 8& represents a certain location on the pole slipping slipping characteristic% &%g% 8& 8& 2 8& 3 8& 4 8& >
= = = = =
Pole slip detected in one 1one start0 Pole slip detected in one 2 1one 2 start0 8ens start 1impedance has entered the lens characteristic0 ;linder start 1impedance is to left of the blinder0 eactance start 1impedance is belo) the reactance line0
Fir% 2 PSL +r LED ,$**in(
The operation of pole slipping startBtrip signals can be sho)n in the Test Port ,tats cell in the #ommission Test men% The Test Port bits can be set to the appropriate ; nmber sing the "onitor Port - men cells 1Pslip Trip ( ;4*! Pslip 2 Trip ( ;4! Pslip ,tart ( ;64>! Pslip 2 ,tart ( ;646! Pslip 8ens,tart 8ens,tart ( ;64*! Pslip ;lind ;lind,trt ,trt ( ;64! Pslip Pslip eact,trt ( ;640% e0 +ppl$ +ppl$ the follo follo)in )ing g voltage voltages: s: Ha Ha = >AHAS! Hb = >AH -2AS! Hc = >AH2AS f0 +ppl$ +ppl$ the foll follo) o)in ing g crren crrents: ts: 5a = A%6+ A%6+AS! 5b = A%6+-2AS! 5c = A%6+2AS% This represents an impedance of A AS% The impedance is no) at point D+F on the polar diagram 1/igre 30% Notice that 8& > is ON! indicating that the impedance is belo) the reactance line% line% 25
g0 otate the angle of the crrent crrent 15 lead H0 ntil ntil 8& 8& 3 illmi illminates nates 1in 1in addition addition to 8& >0 indicating that the impedance has entered the lens% This shold occr at roghl$ 42S% The impedance is no) at point D;F% h0 #ontine to rotate the crrent ntil the impedance impedance crosses the blind blinder er at A>S indicated indicated b$ 8& 4 illmi illminati nating% ng% The The impedance impedance is no) at point D#F% ,)itch off off the crrent and voltage and notice that the 8&@s trn off% i0 Withot ithot modif$ modif$in ing g the voltage! voltage! appl$ appl$ the follo)i follo)ing ng crrents: crrents: 5a = A%6+ AS! 5b = A%6+6AS! 5c = A%6+-6AS% This represents an impedance of A AS% The impedance is no) at point D&F on the polar plot% Notice that 8&@s 4 and > illminate% j0 ecrease the angle of the crrent 1to)ards point DF0 ntil ntil the rela$ 8& 3 illminates% This shold occr at appro'imatel$ 6S and indicates that the impedance is at position DF% Once again s)itch off the crrent and voltage noting the 8&@s trn off% .0 eappl$ the crrent and voltage indicated indicated in DiF% Notice that that 8&@s 4 and > are trned on% The impedance impedance is no) bac. at point D&F% otate ota te the crrent to)ards D/F ntil 8& > s)itches off! )hich shold occr at roghl$ 234S% The impedance is no) at point D/F 1i%e% 1i%e% above the reactance line! line! bt to the left of the blinder0% blinder0% l0 #ontin #ontinee to rotate the crrent crrent in the same same directi direction on ntil ntil 8& 8& 3 illm illmin inates ates once once again again indicating that )e have re-entered the lens at point DJF% The 8& shold illminate at appro'imatel$ 2>S% ,)itch off the crrent and voltage noting that 8&@s trn off% m0 8eaving 8eaving the voltage at the same vales vales appl$ appl$ the follo)ing follo)ing crrents: 5a = A%6+ AS! 5b = A%6+-2AS! 5c = A%6+2AS% Once again the impedance is bac. at D+F on the polar diagram% diagram% Note that onl$ 8& > )ill )ill be illm illminated inated as )e are once again belo) belo) the reactance line% line% n0 otate the crrent crrent 15 lag H0 to)ards point point DYF% Note that 8& > trns off off indic indicatin ating g that the impedance is at point DYF% This shold occr at roghl$ (24S% o0 #ontine to rotate rota te the crrent in the same same direction ntil 8& 3 illm illminat inates es indicating indicating that the impedance is at point D5F and )ithin the lens% The 8& shold illminate at appro'imatel$ -4S% p0 Once again contine to rotate the crrent in the same direction ntil ntil 8& 8& 4 also illminates and the impedance is at point DIF% /or correct operation the 8& shold illminate at appro'imatel$ (*>S% =o =one2 25 25,6 .856
* e c a a t ct n c nc e e $ i n e e
23 2346
=o =one2
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4 2 6
C 6 5 0 1
=o =one1> =o =one2 =o =one1> =o =one2
=' ='150ohms
c c 2C
P% Si**in T%(t
The previos test )as sed to prove the lenticlar impedance impedance characteristic that the rela$ ses to detect pole slips% The ne't test )ill simlate a genine pole slip condition! )hich )ill prove the pole slip conters and timers% The pole slip )ill be simlated sing the omicron control centre! )hich incorporates incorporates a program script that tells the omicron to inject a se7ence of predefined impedances% The program script )ill have several variables! )hich )e can change! and this allo)s s to inject an$ pole slip that )e re7ire% The pole slip locs )e )ill inject is sho)n in +ir% 4)
=o =one2 =A100ohms
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=o =one2
= C C 3 5 0 0 o h h m s
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' A =o =one1> =o =one2
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=' ='1150ohms
2 56 56
=o =one1> =o =one2
31 316 Po Po$e&$ip o ocs
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Fir% 4) P% Si* L#(
The rela$ shold shold alread$ have have the correct settings! as in step b%0 of the previos test% a%0 #onnect #onnect the circit circit as sho)n sho)n in /ig /igre re 4% b%0 Open the omicron control centre program provided b$ doble clic.ing clic.ing on follo)ing follo)ing icon on the des.top:
c%0 /rom /rom the Dvie Dvie)F )F men in the )ind )indo) o) select select Dscri Dscript pt vie)F vie)F and ensre ensre the follo) follo)in ing g parameters are set as sho)n belo)% belo)%
2#
d%0 #ompile #ompile the script% o this sing sing the DtestF men and selecting selecting Dser commandF% commandF% #lose the script )indo)% e%0 Pshing Pshing the Dpla$F Dpla$F btton on the toolbar )ill initiate initiate the test se7ence% The The 8& se7ence shold be as follo)s% +s the test starts 8& > shold come ON! indicating that the impedance is belo) the reactance line% +s the impedance hits Point D+F 8&3 shold also come ON! indicating that the impedance has entered the lens% 8& 4 )ill come ON as the impedance hits point D;F! indicating that the impedance has crossed the blinder% /inall$ as the impedance goes throgh point D#F! 8& and 2 )ill come ON! indicating a pole slip in ones and 2! 8& 3 )ill trn O//! indicating that the impedance has left the lens and also the rela$ )ill T5P% The pole slip applied to the rela$ rotates anti-cloc.)ise at >AS per second% The impedance presented to the rela$ )ill ta.e appro'imatel$ appro'imatel$ A%62 seconds to traverse from point + to point ; and then A%> seconds from point ; to #% ,ince both of these times are in e'cess e'cess of the P,lip Timer T and P,lip Timer T2 the rela$ )ill operate% f%0 #lear #lear the se7en se7ence ce on the control control center center b$ psh pshin ing g the DUF DUF btton btton ne't to the Dpla$ Dpla$FF btton on the toolbar% g%0 5n the script! change the DangleZdire DangleZdirectionF ctionF variable variable to (% This This indicates indicates that the pole slip characteristic )ill no) rotate cloc.)ise% ,tart the se7ence as before and it shold be noticed that the rela$ does not recognise this condition as a pole slip and does NOT T5P% h%0 h%0 8ocat 8ocatee the the GROUP POLE SLIPPING colmn and then appl$ the follo)ing settings: Pole ,lip "ode "otoring i%0 e-start the test again and it shold shold be noticed that the rela$ rela$ no) trips% This is becase becase a generator in motoring mode )ill see a pole slip in the reverse direction% j%0 #hange the the parameters in the script to that sho)n belo)% belo)% This This sets the parameters to perform 2 pole slips% slips%
2E
.%0 .%0 8ocat 8ocatee the the GROUP POLE SLIPPING colmn and then appl$ the follo)ing settings:
Pole ,lip "ode Jenerating one ,lip #ont 2 The rela$ is is no) set to operate after 2 pole slips instead instead of % l%0 #ompile #ompile the script script again and psh the Dpla$F Dpla$F btton% btton% 5t shold be noticed noticed that the rela$ repeats the 8& se7ence in step De%0F t)ice and after the second rotation rota tion the rela$ )ill T5P m%0 We )ill no) prove the timer time r operation operati on of the rela$% rela$% ,et the script bac. to the vales as in step Dc%0F% /rom the script it can be seen that the step time is A%secs and the step cont degree is >% This means that the impedance travels > degrees ever$ AAm,% Therefore! from +ir% 4 it can be seen that 21point + to point ;0 is 3degrees and 31point ; to point #0 is 2degrees% 2degrees% ,o the time it ta.es for the impedance impedance to travel tra vel throgh 2 is 113B>0?A%0 = 62Am, 8i.e)ise 8i.e)ise for 3 its 112>B>0?A%0 = >AAm, 5f the impedance does not pass throgh the region in a time slo)er than the Pslip timers T and T2 are set to then the rela$ does not recognise this as pole pole slip% n%0 n%0 8ocat 8ocatee the the GROUP POLE SLIPPING colmn and then appl$ the follo)ing settings: P,lip Timer T *AA ms P,lip Timer T2 6AA ms Note that the impedance impedance )ill )ill pass throgh the t)o regions before each of the timers time time ot% o%0 nning nning the test )ill no) reslt in in a NO TRIP condition%
29