(or ormalu", SlotSl pcr po~. If tho", are 48 coo
26.13. Conductor The length of" wi", lYIng in !be nUlg""tic fitld .00 in "'hich an e.m ,f, i, inducW. ;\ called. condUClOl" (01" IndIl
896
Electrical TlIChnoiogy
26.1". Col and W".IdrlQ EIemenI With ",ferr""" to Fig. 26.%1. ~ ,,,'., COI>dt>CIQI'S MI aod CD .oJoog ,,-;111 tht:i,- eoo connn:u.,... romtilule one toil of th<' annalWl' "';nd;nJl' lhe roil may be .ingle-Ium coil (Ftg. 26.21 ) .... multi· lum roil (fiJI. 26.22). A sinaJc-lum coil ...·ilI ba,'e 1"" coodt>ClOn. HUll multi'IW"ll rojl may ba,'e many ronducoon per coil .ide. In Fig. 26.22. for exampl<. ~""h roil sidt Iw 3 e<>ndt>C'Of'I . "..,
,,
,
,. ••• ,.' c
//Cy." --'::-.. :, '.
1
•
,
,,, ,
U
......:;~>, ';-',"
,,,
I.,. I
== 1
JfWP of ,,-ire> or rond"""", ronstiluung I roil side .,.. a multi·l,,", coil ;. wrapped with a tape u • lUll' (fi JI. 26.23 ) and iJ placed in tho annalu", 0101. I, ""'Y be n<>.ample 26.1). "Tho ,id< of a roil (I .lum '" m"hi,um) i. coiled a winding ele"",nl. Obviously. the number of "indi", elen .. n" is ,wice the number of coil<.
26.15. CoI·span or CoII· pltch N.) 11 i. the di.w.:e, meuured in 1<1m. of annatWl' Uot< (Ill' orm.11U", coroducton) bel"'..," ''''0 ,ides of a roil. II is. in ,~~ tt.;: prriphc:.-y"" the ;ormaIUR'spanntd by ,he ,wo . ides.,.. the a.>il. If the pole span '" coil pilCh i, equal II) tbc pole pil<'cn assumed). lhen winding is tailed J./J-piIt:~. It.....-ans tha, coil $flU is ISO ~I""lrical doJ"'C'. In Ih'. taSe. the rojl .ides lie undor """",itt: poles. ~ tbc indUttd ~.m.f,. in them "'" additive. 1'lIon:'.::n. "",.imum e.m.f. i. indUttd in the rojl u. ,,'hoIe. il be,ng tbe ' Urn oftbce.m.h indUttd in lhe lwo coil . ides. I'orc>.ampk. if the", "",36 _Iou and 4 pole .. thrn rojl span i. 36/'4 _ 9 . Iou. If number of.1ou i. 35. then 35/4 • 8 bee.u,,", il i. cUllomary 10 drop fractioM. If tbc COIl 'I"'" i. less than the pole pil
t:a5e""
r• •
FIg. 211.z.4
D.C.o-.lo.-.
897
.... indinl ;, f...roo..al_ p;r.:br:d. In 11>;' "-- Ib thr: c.m.r... in the , .... 0 .ides 0( the coiL. Hence. the IOta! e.mJ. """"" the coil which is the _ .um 0( •• m.fs. itJ thr: IW<) coil sides. ;. Icso in this C&5C '" compared to that in !he r"" C&5C.
26.16. Pilch of a WInding (V) In I ..... ra], il ""'y b< kliror.d ... tb< di~ """Dd tb< armallUe bet,,·..,n Iw<) .lICCtMi~ rondllCCOIII>e<"Ied IO~. Or. i, iJ lhe di.W>Ce between the bepllll;ngs of ' .... 0
lOr!; which !lie di"""ly con5CC\lli~ \WIlL
r .. Y. - YT ........for I"" ""Dd,nl
I,. __ .
- y...
_forwa~wiDd;nl
10 ~. cod-pir.:bes as low as cighH<1IllH 0( . pole p;tch on: employed ,."thoul much serious rcd""tion in tb< e.m.f. FnoctionaI-pitcbcd windings are purposely used IOcffClCt substanlial l.lvi", in !he copper of !he cDd and for improving cornm..w.i"".
"",,,,,,,,lions
26.17. Bock PItch ('f ~ The di.oancc. measured in 'cnn. of the Iml.II"", conducton. wltich • coil ad""""", on !he lNock of !he umal"'" i. called back pitcb and i. "'IIOIed by Y.. A5 "",0 from Ftl_ 26_28. clement] " COIII>e<"Ied "" Ihe lNock of tb< armature 10 dement 8. ]-k,.,.,.
Y. -"' (8 - 1) .. 1.
26.18. Front PitCh ('f; The number of umalure conducton or clemen... panned by • roil on Ihe fronl (or cornmutalor end of on """",ure) I. called thr: fronl p;Ido and is desi"""ed by Y,. Again in Fig. 26.28. ekmen' 8 i. ronnoc:ll:d IOckme",J on tb< Ii-onl oflhe armaIun:, the connection;[ b<;ol made at the """"""",lOr .. pnenl HCIICe, r, _g_J .. S Al""" .. i~ly, thr: fronl pitch may be: defined ... the di~ (in II:nn! of """"'''''' <:OoIduocrors) b<, ........ lhe second condllClOr of one coil and lhe lirs, ronducIoroflhe IICJ
-
-- '. ~ .
r
- r,.:-
f"
211.25
I
FIg. 211.21
26. 19. Resultonl PItch (Y,) II .. the dlSlalltt bciWtttl the b
898
Electrlclol Technology
$tOm! in lenDS of ~
lbo sometimel liven
conducI
,n Ie"'" of armaIlln'
ilou or CO
Lor
26.20. Commutator PItch
('f .. )
I, i, ,he diOlallCe (.... asu~ in COI1lIIlIIl.1Lor ban or ....... nlli) be, ...ttn ~ ""' .... nt< to ,",'hkb !be 'woeoo.. of .coil "'" connteled. FnJm Fil. 26.2!l and 26.26 il i, clear \ha, for lap winding. Y(" i, \be tIUJ~ ...... u of Y. and Y~ whelUS for _vewindinl il ;. !be JIUII of Y. and Y... Obviou.ly. commulalOf pilCh i. equol 10 the number of In.. be,ween coil 1oO
fIg, 28.28
26.21. Single-loy., Wloding 11 is tItaI ... ,nd"" in wlUch one condUo<1Or orone coil ..... is plaad in eacb arnwun: slol IS ~n in Fil. 26.27. Such. w;ndinl is not much 1l5ed.
26.22. Two· layer WIndIng In tb .. type of wtndtng, !ben: are r..... conduc,on or coil ,ides per slot mange
D.C. GenellIlors
899
26.23. Degree of Re-enllanl of an Armature Winding A willdill3 i. said 10 be ,ingk re-
26.24. Multiplex WInding In ,uch windingll. then: are sevmd set> of completely closed and independent windings. If!b(re i. only one set of closed winding, il is called .irupkx w..·• winding. If \be.., an: two sucb winding' on th<: .arne annaIU..,. it is .a11 ... duple~ wlndilli and .., on. Tbe multiplicily affO<"t!i a n"",ber of p;oralkl path. in lbe annature. For a g)"cn number of arm8lure .lots and eml ..... 1be multiplicity ,"""'ase$, tho number of panlkl path< in the armature i!>Crease. thercby increasing tb. currenl rating but decreasing the voltage rating.
26.2S. lap cod Wave WIndIngs 1\0.'0 typ.,."f wllldings mostly .mployed f.,.. drum-type armature.,.re koown .. Lap WilHling and Wave Winding. Tbe difference bctwun the two i. me,toiy d..., to the different atra/Igement of the.od e<:>nJIeCtion. at the fmol '" oommutator end of armature. Eacb willding can be ana"ged progressively or R"tnJgrCUivcly and ct>flJtttte
.., ......
,
lil llIc front pilCh and back pilCh are each approximately C<jual to the pole. pilCh i.e. windings O&C". fractional.pitched winding' are deliberately used (Art, 26.13). 1111 Both pilChe:s ,hould be odd. otherwise it would be diffICUlt 10 pi..,., Jbe Mil, (which are forn-.er--wound) properly on the armalure . Forumapl •. if Y. and YFwere both even. the 011 the coil ,ide. and c<:>nducton """Id lie either in the upper half Oflbe .Iots or iII the Io,.'er
900
Electrical Tachnology
... If tknee. 11 """ld become Ifnpoosiblc lOr OAt side of !he roil to lie in !he PPJ>Cf half I ~. " ....... 1<1 beoome impoMlbIe for OAt ,ide oflbc coil'" lie I4Ibc uPJ>Cf balf $kJI uod Ihc odor:r
of.-
,",'
J.) TIot " ""hnl mote uJ>OII " 5")( I.t ,f we.t.on from a ,iven poin, and move from """ coil to anothc-r. ,hen III cood!IC,or. dllluid be 1I.. ,..1Kd and "'" should roach lho .. me poin, ilEain ..."hoot I !:ftat or di"'"OOlinu"r in bel".ceO.
26.26.
~x
Lap.wIndIng'
II IS ihowrI in ~II· "l6.2!i ...hieh cmployuinSk>-rurn coi", In Lop ""IOdin.. tht flflUhu!& mel of "';1 .. o:onnccted 10 • rommuIaIOf lItpnQInlS rogll'dlllg limplcx I...... ind,ng ,hould be carefully 00ICd' I . "Jbe bKk ."d frun. rO'che> Ii'll odd and ol """"",it< .i",. Bu,.ho)' ran,"" be equll. 'I""hcy diff... by 2 or""""" multiple 1hc0"C0f. 1. fIOOt Y. and Y, .t.ould be nearly equal.o • pole pit
.'.
~ ,,'Q'ICI' potdo YA ..
r• +2r/
7.
II «j,w" poIc pol
4. ComnlUlXOrpolCb Yr -",I Clnrcnmol. Yc ,"",m) ~. R....IWII poleh Y. is evrn. beln, lho anlhmeocal Iliff..........,
of,,,,,,, odd IlUmbel"ll. Lt.. Y. _
Y. - Y,.. ..
",. number of , lois for • 2·layer .... mdinC is equooIlO tbe number of coil' (i.t. h
,
,
,
, ~
• , , • , • , • •
" "
"
),
i ,~
" •
• )'
"
,
.
" " •
".' ,. , ;1 · • , • • • , •" • IO F:• "
.I
,
S--
'"
lop ""'"'*'II
---------------- - -----------• • ...bd ()(IIDn>UI*>r boB 10 OlIO "'1lIhna tnd tbr. odd·....- """" .0 lilt ...,...,., "';ndi",. S,mil>riy. ;" lripIcA lap ,,~, thrrn would boo "'- ...1JId,"i'- cad! """"",ted .0 (1<10 lhlf'll 01 tbr. <.,lmn ....... bon. _
...~ .. otumcd ..,.
D.C. Generator, 7.
901
11>< ~umbr, of p..... ld prulI!. in the annat"", .. ",p wbere '" is the multiplicity of the winding
r
and the number of pol ... Taking tbe firM «m rri.•. r. ~ r f ~ 2. thenwc g" • pmgre","'c or rig/It.handed w""linK I.•.• winding prog=ses In the clock .... ise din:cllOll as,\eOn from tbe rommul
.,Inch
~
, r... Y,
,
; + I] for"'lrogressi'"ewinding
; - I ] forpm,..",.ivc winding and
Y,
p+1
Y. . . .. - I
a
ObnO\l5ly. 7/P mUSI be even '" make Ihe winding p
"
26.27. Numbering of ColIs and Commutator segments In the d.c_ winding diagrams '" follOW, we will number the roil. only (Il0l indivi< upper ,ide of the roil will be ,hown by a finn con.;n....,.... Ii"" whereas lo""cr ,ide will be ,hown by a broken line. TIx: numbering "feoil ,ides will be consecutive i.t, 1.2.3. _etc_ and such "'a, odd numbers are lL'l>.igned 10 tbe lop conduclonl atld eVen "umbe", 'o.he low"", ,ide" lor. Iw<>--lo)'..winding_ 11>< rommuWor segmonts wi!! also be numbd consecutively. the number of lhe <eg' menlS will be the IIIUIIC ... Ib., of lhe uwe' ,ide con"""",d to il. E~mplc- 16_ 1. Drow a dt'-e/oped dWllrtJm 0[ a .impl. 2.la),,,r 1trp'"·indiog!vra4·poI,, gt""rtJ· ror ~'ilh 16ooit.. 11.",,<_poior ""r rllt ~1rarM'r.riJrk~ 0[ a 1op."'indinS_ \F.1c<1. F'.IlJ!lnftrinl:. '1adr:l> l'Ili •. 19S11 SoIlltlon. TI>e nWlloo of commutator segment" ~ 16 Number of condoclors 0.- coil.ides 16 X 2 .. 32; pok r"tch .. 32M _ 8 Now ",,,,,,mbcriog "'al (I) r. and f, ha,e 10 be odd and Iii) ha"e 10 diffe< by 2. we gel for a progI'e',jve winding r. 9; Y~~ -1 (",Im~"i"e windiog will "'>Ill! if r." 7 and r, .. -9), Ob...musly. commutaro.- pilch rc ~-1. lO!herwlSC.'" sbown in An. 26,26. for pI'OgIa,ive winding 32 Z 32 r, m Zp-I~4-1 .. 7andr."p -I~4+1 -9J
L""
%
11>< simple winding LObI/: Ii gi.'tn,.. u.ukr:
C""".rti",,.
110(1 .. 9)_10 310(3 .. 9) .. 12 310(3 + 9 ),,14 710{7 .. 9).16 910(9 -0- 9).18 1110(11-0-9) .. 20 1)1O {13 -o- 9) .. 22 1310(13 .. 9)_201 1710(11+9) .. 26 1910(19 .. 9) .. 28
~
Fro,,/ IOlo(l0 -7)':3
~
121O(12-71~5
~
1410 (1 4-7) .. 7 1610 (16 -7) .. 9 18(O(l8-7)~ 11 2OIO(20-7)zl3 2210(n-7)z15
~ ~
~ ~
~
24'0 (24 -7),. 17 2b '" (26 -7)" 19
~
28(0(28-7)",21
~
902
Electrical Technology 21 10(21+ 9).30
~
30 10(20-7).2)
13 to {23 .. 9) .. .32 2510 (lj .. 9) .. }4 .. (34 - 32) .. 12710 (27 .. 9) .. J6 .. (36- 32) .. 4
~
lllO()2-1) .. ~
~
210(34-7)_21
~
410(36 -1)_29
29,,,(29 . 9) - 38 ~(38 -32) .. 6 31 10(31 +9) .. 4() .. (40-32).S
~
610(38-1)_31 II 10 (.10 -1). JJ .(33- 32) .. 1
~
, • • • r
1' [28 . 12
2"
Z6
~?O · J2
-
2.6
_' ,<>Y:XX,Y:/~/
• ,1 ) 1 6
· c
7
• .1 ' 1. 10 1 11
Ll ,' 11 1 I'
B'- . ' - P
I I I 10 J 11 J '.7 16
p
~I
,.,\.>-"" ~..".
~
11 11 :lOLl
t' \ Ie
\I I)
,,
I
IJl'l:U11Z619211I.lOlllJl~
1\
fj .
221. l'iI 6 31 I I
'J .'! 1) I'D~ ' I IJ
~ '
15
,
(
N
\
Tho proce
~
\I
0 '
fit. 26.31
u~
D.C. Gerleialors
to3
flUlll we complete the windi .... 1II11S indWin, every roil side orw:e uU we "'lOCh the roil side I from ~ ,,'C IUrIed. hJcidmwly. n Iobo\Ild be I!Id Ih:oI :011 ..,.,... COIl ~ hI,·c beftI liven odd ......tIm. whc=as ~ """" M>C beeIo ,hen ew:a ....m.n 8$ 6ho"h posil""'" caD be 1oca1Cd by findln, the dim;1ion of cum:nlS flow"" ill the variousmnduc. KIn. If CUr=l1l in !he roOOU<:1Of1 underthe inn..".,., of. N·poIe we NSllIned '" flow do.,.. n.....-.!s (~ .oo-,.·n). 1"'" 1bcst will now .."wards in CQ!Id""1Onl WIder the innocnce of S·p<>Ic. By (>J!tinl proper :amnA.,u.ly In the equivalenl rinl di.""m). il i. foor>d thai OOrnmu11",," bin Nn. I and 9...., the rntc1i ... poinl.O of e.m.f•. oad fU~nl.O we nowinl 0Ifl of~ condUCl<:n. "!be "",iii", bru ..... ohoukl.then:fore. be pI8ccd at tJ\eje tI>(.1olor bin N(l. ~ and I] ""' the al'panti ... points 01 ... m.f•. be""" nep1.l'" brushes ..., pI8ccd 1hoIo-c. In IOn. then! "'" fow- bru"- lWO poaih..., and I"......pb .... If brushes 01 the same P>!lrilY an: 00IInC<:1Cd .... d.... then alII'" ormIIUIe ~ ..., divided iqlo f(U pKIOlIel pMhs.
""lICe
"
Ag. K.33
Divi.ft as the numberof "ThtI is .'IIy auch. w'ndiDa; is _ ..... llple circwt" 01" ·patOIlc]" w,ndi"l- In gcoenI. n.".\ber of parIOIlcI pUlIs III......nR.,..p w~ 1ft ",the nn>lllplk,ly (plcx) of the lap "'IIIdi"l- For eumple. a 6-poIe dupIe.1lap w,!>du>1 has (6 " 2) _ 12 ~lcl paIlts in its annalure, .\, T1x: .,m.f. be1wecn the .'" and -ve bru>hes '" ""1111110 the • •m.f. ~ in any ..... of the pa ... I,"1 palllo. If Z '" the 10111 number of """"lUre condU<:1on and P !hc number of polio •• ,"'n the number of onna'u'" oon
""""""II .. ·......
"'*",
904
Electrical Technology
. ~.
Geoenucdc.m.r. .f.~.(A' ...",ccm.rJ~)(
zp . '... " zI'
n.c IOIaI .... cqIIlvaient ..,...,tlft ~ can he found II follcr&s ; I~
kn&th 01 exit arma,ure condl>ClOr; S. ItS """,,·occtioon
1 '"
A '"' No ofpanl1cJ plIth. in;t.JJNIun: _1'
fotSil!lplca lap "tndinll
~wv
,
'"' ""iSla""" oflhc ,,'hole "" indinS then R - S ~'• ._
I.
!,,/4
"
'v ' ~
•, -
1,,/4
,
.~
L
r
I
I
c:fJ
1
I,
,~
I.
j
Rc.,~ of exit palh '" --Pl~
'" '*'" 1."
1bcre are I'(ot A)...,II
• ~
A
,n ~kL bcncecqui'..JcnI ~ plZ .. ~
SA
SAl
I( I. I~ \l>o Intal annalufC <"\I'l\'nt. th.en =
t I"" ~Id p,uh (ot carried by each condllC-
,,,,) i,I) I'.
26.21. $lmplel Wave Winding" From Ftl. 26.31. it i. clear thaI in Lap '" ind,nl. a condllClor (ot cod ,ide) IlCXt ...-poI<. it _Id mob 110 dtfl"c~ III for as the di~ion .ad fIU&llllt>
~.t the bKl to. condllCtot which
--. •
on
"""n""' ........
l"!' ..inpl...... '" windinS fOlK potho ...... ,nflka Me: ';~ polIoo...,
UI.c
'wo
D.C. G..-8tO,.
, ;,
IU ....... in fi&. 2lUS.conducIor All IS COOUIeC1Cd 10 CD lyi", Ilnder S-poI< and Ibm 10 CI"~lh.oo.oiIN·poIe, In LII" .....). Lbo Wlndu., prugi : pUi' "" lucce;.oh'.ly under .'"efY N·poIe and S·pole lill il rt1l1m> l(' a ronductor ""S' I)",nt uf>ller \be oriainaJ pok 8«au>c the "'Indint l"''i'""'iIa in one difI'Ctio<1 10000 the amw= in .. scri.,. or ·"... v...·. il i. known as ...... ve W,ndlJl&.
,.
, ,
, v;" /-,
.,
-I -
...
.(
I1JWIlIIht: or· >10110 !he itA "'''~'lM\UlI pooIl (alA'S' Ut Fi, 26.)5) tbem!bo W>DdlllJ is !laid 10 K ~,~ If. bow· e.'er." fall. one 0loi 10 !he righ~ Ibm il ii ~,~ Amln>Ul, .. 2-Loytt w,ndin, and JUppooin. that coodllClOr tlB h~ In !he uPJI"f half'" lhoIliot. !bon lOOn, DIIC
If. afIcT 1*";",
FIg. 26.35
<MK<:
maI_. Lhc ""U!dina fan.
III ..
I'rom the above. we caJI dNucc the fuliowin, ..,IaIJOR5, If P .. No. of poIe<. thnt
Y, .. r-k ",l<:h
...
YF .. fn.1I pt...,b
I
narly equal 10 pol< pttch
,
Y, .. YF ... ,~ pildl ; Z __ ...... No ol coodlX"lOf':S or rotJ ........
SIIitt I' is al ..... y. c"en and Z ..
mean. IMI
L;
,."--P '"
ry. 7- l, h.encc Z "'uS! al ..... y. bo: e,'en.
Put in anoIber
".y. il
2 "'''', he an even (nICS<',
l"Iw: pl~ "an wili,;"". r>«>&J"O"Ive
wtnllulJ:""" doe ...... ~,.., si..... ~vc "'1001",.
Porn to NoM :
.'. t.
Bod> fIII<"I- YJt - Y~"" odd""", of 1M ...... Ii"'. Boo:k -.1 f ..... p'ehet.., pearly equal to!bo pole ptlet. and .....) be equal or dIffer by 2. In ",h,,'h ClISe, !bey "'" tUptXl;'cly 011< ."..., or one Jc.. than tbe .ve~ ",tcb . RC'ulwllpilchY."YF+Y,. Comrn"t.a!Or pItch. Y," )', (in lip" inding Yc ""' 1). AI..,. Y .. No. ofCorno ... WDr """ t I f
The ...... pok;h "htch
No. of pair 01 pole> _
,~ "val!'!.~!C-~orbars:t1
be an UI\qICrll>
r, _ Z!2 .. ,.
by
..
1'12
S",,,fl"itofpob
II .. dc: ... thai lor Y~ 10 be an '~Jj:r.1bcre J.> a reotnctoon "" lbe vaJ~ 0( Z. WiLlI Z _ 12.. IhoJ .. ,ndlq " """",,,br.. for • 4 pule I......h,..., (thou", lap "",,"'illl i> ptllbibr..). Vah"" of Z .. \0 or 34 W<J\l1d be pc:rf
••
The number or "",I. i_~. HeCM lor. round from It.: ~Iation. PYo! ± 2 He" 2
"
Th" ~1IbOn has bttII f(JUDd by rurrangtng ~ ~Iauon si'"aI In (S) above. his obvi,(,n numbers ",h;"h ar-" un>uilablt. for llI's winding. TIle number <>f am .. lu~ puaJld palh.< .. 2m .. ~ '" i, It.: rnuillphc"y of !be ,,;ndinl.
7.
8. E.umplt 2U Dm", a dev.loprd dUll""" of .. 8""pia 2·/ayu ....' ......·jlldml/or /J -I-pok d.e.
of" .impk "vW rFJKl . ....'11.1. "'''IP''r l "h. 1"11
I<"""ruIOl" 1o"IIh J() ",,,,,lIurr rottdwlbn. Hrna. "",", ...11 1M cllDr«,.rljlu,J
...iN/iItt S....d"• •
~ YA..
JO 4± 2 .1. .... 7.
TaIun& Yo!. 7. we ha..., Y•• Y,.1
,
,
i .. , ,. , , , , , , • " " "" • • • • • • • • • ,, , • , N
1110 1
, , , , I • • • •" I I ' I , ,
16 21.10 1 ,. 21
1]1017'
R
Q
...
..
N 19 2I'i 1 10 "
~
A."""""" in F". 2636 and 26.31. c:onducIor No.5 is IIkn IOCOIICIIl S at ~ &onI.. Nexl. It.: ccnductor No. ]2 is joined 10 COIIIIIIUWOr ............ S + 1. ]2 ( ... Y(". 7)IO",bicb isjoinedCOGduclor No. Ih 1. 19. Contmu"'l thiJ "'y, .... """'" '*'k 10 cxond_ Nfl. j from ",.~ ..., 6IaMCd. ]Imctc. die windinl closes ...-
,... ]f.
•
r...
r, .. 7 or r. .. 7 ond r, .. ~.
If M W;e S.!hrn the potcloos """,1<1 be , ~ and W:cn .. 7. annaton: ";ll _ ...... do_ion and if
In
.. Yr I,
r c" 8. it ... ill ro
D.C:. ~.tors 1k simple WIIIIlin/l; IIMtC _Iabk: _1$" WIder
907
f.-C ..... M .. 81O(8.').I~
11
2200(12.7).29 610(6.7) _ 13 2910(29.1). J6. (36 - 30).6 1310(13 .. 1).20 2010(20.7).27 2710(27 +-7). 34. (34 - 30)_4 410(4.7).11 II \tI(II. 7) _ 18 1810(18.7).25 2S 1(1 (25 . 7).32 _ (n - 30) .. 2 211>(2.7).9 910(9.7).16 1610(16 .. 7) .23 3010 (30. 7) _ 37 ~ (37 - 30)_ 7 2310 (21 . 7) .30 1IOn+-1)aI4 --------f 1410(14 .. 1) .. 21 -------t 21 to (28 .. 7).35. (35 - 30). ~ 2110(21 .. 7) _ 21 -------t 12to(12.7) _ 19 ~to(5.7).12 --------f 26 to (26 .. 1) .. 33 ~ (33 _ 30) a 3 1910 (19 +- 1)",26 31(1(3.7) _ 10 -------t 101(1(10.,).17 --------f 24 to (24 .. 7) .. 31 _ (31 - 30) .. I 1710 ( 17 ... 1).24 S,nce " 'e co_back to theCOl'ldUClor No. I from w""", we .W1ed. the winding ~eu c"*<1lt Ih,s
--
""'" ""Ilion
I..Oed to be """"a, (rom Icli 10 ri,111 DYer the poles. By appIyinl AefII,..... R'ib'·hand ",Ie. the dill!ClloN of dot U>IIuced t .m.f. in various ........ ....., oona)v,'n In the "lure luove bttn f",,1Id in ""$ man"", tn lbe lowt< pan of R,. 26.36 is shown the equivalent rin, or "1'i .... diagJVII which;,.ery helpful in IlJIderstaodinS the fDnrLllion o( v"';O\IS pMIllcl path.- in the .....1..... 11 ;u"en lhal the windin. iJclc<;trically divided inID IWDpon ...... . 0... ponion ronsim of ronOOctors Iy,,", bot_n pointt N and l. and the 00.... of ccraducun Iy,,", bcIwcm NandM. In the ftBt ponion. the v-al1rD>lI of FIg. 2-.37 dot indIIad ~"'(L is from left 10 ngbI wI>cmas in the scrond ponioa il i, from rigIM 10 left. H........ i............. ....,..,.., only 1_lMIflllcl pMh< through the ...,1Id,nliO thot 1_ bn.to/IQ ore noquiRd. on.. po6lli~ and ' - ""'I";"'" From the "'t",v"'n' rinl diqram. II i$...",!hat pDUII N is the ~pontin.. poinl of the c.mJ•. Induced in lhe IW{l ponions of lbe w,ndin •. H~ncc. !hi. fi~es lhe posilion of the negati~ bru .... 8uI at il ;1 &l lbe back and not al lhe con\JlIullUor end of the ormMuf'l/. the negativc brush has IWO "I.''''U'~ posuioru i.~. citllt< poinl P or Q. "These pointl on lbe "'tu;"alent diagram COI'TUpond torommUlator ..,,,,,,,nl> No. ) and II . N...... we will fond the pos,tion of lhe pDlili~ brush. 11 is (ound th.ll ~ arc two mtetinl ""'MI of the induced C.m.(L i.~. "",nb l. and AI but both these poanttn &l the _t 01" """..,.,...mu· \alOf ~ of the arrtWlItt_ "IlIQo: t_ poinu n ~ by on.. Iaop only. namely. the Iaop com· poIfd 01 condurun 2 ....:I 9. loot:rM;e middlc point R of tIIl$loop fius the position of the posiu"" bnM. ... bit .. ~ be pla.:ed ;., with commUlaKJr """"",ftl No. 7. We fmd that for OM poI,tiooaof the.~ bnM. ~ n 1_ .llC1IIliv~ positi<JN (ot the - ve brush. Tabn, the +vc bnM at poinl R ....:I IICRlt,VC bru
II
w *"'''
908
Electrical Technology
• ,
In palh I (Fil. 26.36) i1 is found lhal e.m.f. incoodoctOl" 9 i, in oppot;ilion to Ih" ,,,... ral!tO"" of e.m.fl. in the "'ber coodOClon compri' tn, tbis path. Similarly. In p.:tth 2. !he e.m.f. in coodOCI(M" 2 i. in l"l'I'ition 10 !he din:<:IWn of •. m.f•. tn !he palh as I ",boLe. However. this "'ill "",k<: 00 dirre",no<: bee.use lhese conduc!
,, •I
,
- 'all 10 J 16 19 U S ' 21 11 H
1 XI
II
16
9
PATlll
11 l 4
I
S IS 12 29
6
13 10
'.
n
4
II
II 2.S 2
• I
P"TIt 2
...~
A. . .. taU "'" ~ of ~ 2 and 9 ..,twtd 1><1....... poo~ I. and M. Since the ...... u~ rondu
.
D.C. Genefator. ""her;1 willlncn:asc in ""'KmIOOt gradually_ It _ Q
~
r
i
"
I 8
l~
~lo--3 2~
Ia
P
Ian
-
22
"
29
6 - lJ
20
th;i.(
21- ~
12 -S - 2B -21 - 14
-~.
in a very !ohon interval. point M will PATH I
11 - 18
25
II.
2~
,~~ ll_-L'~--in.. ~] , :'1 PATII !
lull
909
L,.
Ag. 2'5.4O
beoomc \be """,ring point of !he •. m.f •. BUI as ;( lie... (he back he< are used. lhe nurnbe< of p;lnllel palM lhrt>ugh the """"mre windi", is stiU IWo.
"'g""'nt
thc alx,..., fOCI .. wc &C1 Only two bro.,1Ies are necessary. though their number ,nay be equal to the nurn ...... of poles. n.e number <>f pa"tllcl patb!llhrough the ann.lUre """ illng" lwo ,rrespe<:1J,e of the nun,bcr of gener-uo< poles. ThaI i. why thi. ",inding i< """",time< ~ancd °lw"",,ireuiL' 0< '""rie,' w,nd",&. n.e generalor e.m.r. i. equal 10 the c .mJ . induced in 1liiy one of the tWI} par.t1l.1 paths. I f~_ i, the e.m.f. inducedlcnnductO<. thon sener.Uo< c,m.f. i< E, • ~.. " m. n.o equivalent """"ture re.i
S""'ntari~;"g
l. 1...
26.29. Oummy or Idle Colis Tb<:sc an: u;c-d with wa'''''''''indi", and an: resorttd to wben the rr<]ui"'me"lS of !he "'indinS an: "'" mel by the Slruldanl """,,,utt punchings available in arntalutt.winding ohop>. n..sedummy coils do noc in".,.DCe the e!<>elrical dtan.ctcri.tics of the winding because they an: noc 0""""""'" to the rommulator. "IlIey are exactly similar '" the orher coil. excel" thal theirer.d. are "", shnrt and t.o.pe
"ac"
910
£I.cltlcal Technology Y
•
•
orhicII does _
come CIUllO be: ..
2:*2.60:12 p
~....
•
(Art. 26.211) .. nquimI by tIwI willdi",. However. if_
ma40nc roil dummy 1l(l1haI_""~ S811Cti~ooodun<Jn.!hen "'A - 3':12 . 14 ~ _" 4 Thi. make. the .... indillS
~ible.
26.30. Use. 01 Lop and Wave WIndIngs Tho IIdvlI1tate of the """v~ windinl is tIw. for a.,Ym IILLnlbc:r of poIa and anrwureCOlld""'
acnrnwn
bcc._
Tutorial ProtHm No. 26.1 I.
wm. _'II "'" ""ncIina table for 0 2010)'«
.... ,,"Yin,
1001 lOoiou ond li\ IJ _ What onlhollocl.ond rronl pi"'bcs .. . . . . - in """"otonnaum:_ 1 l" ln! , (a) N<.. .r.-IIdon .... , r•• II _ r,.""'1 ([ loci. t~ n p ....rI"" \Io,d_ l' ..... 1971)
J6J840Z46810
'1~AAtAA
,
I0J1I~16
8
F""", 1.
1820221426246
! t J f\ \V'//
1
J
5
7
9
,
VVV
II
IJ
H
17
19
\'/\" 21
2J
25
1
WIdL 0 ........ 2-10,.,. _"'" """'"" ""vIoot 26 ••• .. I • ..:l 4~ ....... "".... Iho: -..I bod podIoI of .... ~ 7
Iable. WIIoo ..iU be lilt _
111i00i, I, .. ' .....
I.'"~l
'f~tW
WUIdioIC
'bdol.....,.·I, \h,d_ \ 'nj,. )\oQ" 1m,
, " , From
9
11
25
214261124/0228
II
2J
" ,
Ii
" " ,
195173
[. it _ible!O ... oimpk~ ..."" ,.;ndtnJ for. 4-poIt d .• _maoII... wi'" 23woductor> ? &f>Iain tho "'aootI for ~_ ....""". (No. it "ouId .....1• ...., 4 <1if\l ""'" be roue or w;.pol< if "" dwn",y ooil! on: to b< W<>d (oz) 33 sloIa, ltiS """"".......". .."""nu (b) 64 oIots. 2:16 COII'lJnIlUIOr ""&rnnIUI (e) 6!1 >Iou. 260 OOII""U....,.. "'IlmefiU. U_I 4-poI< bop ,,10. <'OmmullIler III ... &:l ....pol< bop. ~J .l-polt lop ............... willi ..,..,.. u ....... pi''''' 15. ItI "poIo. ...... ,.;1lI ...,... u ...... 1'1'<10 ,.,,] J.
pi,,,,,
26.31 . Type, of Generators Genenu"", are u,ually classified acoording 10 the way in wh;"h theic f",ld ......,died. Genera'''''' .....y be divided ;"to (. 1 separa'"ly-<:'~il".j genemwn and (hi self-excited g.... ""0<5, (. ) s....,..notely-ccit ... ge ... ralors an: Ih<>oe who6e field magnets an: .""gised from an indo_ po",,"". external .'lOlIItt of d,c. curttnL It i, .hown diagram.tically in ~i8. 26.41. (tl Sdf..ndttd ~ .... ton" an. !bose woo.e roeld magr>eUl are energi$cd by Ih<: = n ' I'«>" duccd by the ge ...""on themselveo. Due to ,""idual magneti'm, lhcrl' is alway. presenl """'" flWI in the poIeo. When the armatnre is rowed.:IOm< • . m.f. and hence some: induced cWTtn. is product!he manner in which their field ooill (0.- wiooinp) are coonecl<1llO!he ant\31UI'O. II) ~hu n( ,....und
n.., fidd windings are con_led amlSS 0< in I"'f'lliel with the annalure conduclors and ha,e the full ".1lage of the B"net'810< al'Plial OCR ... lhem (fiB, 26.42).
Ii....
~ne.
,
\\ ound Ish
1, ,
,,
~ ,
~
•
...
FIg. lUI
In 1ltis C&>e. !be fieW windingo are joinod in .. rie. wilh the annalure conduclon (Fig. 26.43). A. they cany full )OIld CIUI1!nt. !hey cons;'l of relati .... ly few turns of thick wire or o!rips. Soch genemon are rarely used except for 'pecial PUIpOSCS I.~. as boostcn rI/;, (iii) Con'pound ",ound II is • combination of • few ~ and • few shunt ""ndinp and.an beeilher sIIM-shUllI ()f long_shun( as shown ;" Fig. 26.44 (,,) and
',)
](l •
J
-
... a~
~~
.' ~"
-,., , . -
•
I
I"
j,~
j
~ r-I~Od
J '
FIg. 211.44
·"1,,1 , 1"
- 912
E~ITechnology
\110) resptaa !he I\rr'Ie$ r... I"- When series roeld tWIs!he 011 ... , rleld, gencntor is uid La be commuwivcly.a>mpOUndcd. On the otherI>and r..1d _ !be shWlI rock!, the gmeralor is Wd La be difJcrt:oLi.lJly comp<>llll
'f"""""
DC.o.~
Self Exoited
l
'-"'-
• Looa ShUn! -
~
FIg. :M. •
vol.
26.32. Brush Contact Dfop II IS tbt drop 0Vtt the: bru>lI oontaCt ~_ .../lcQ = 1 ~ from commuUllor Rpnen13 10 bnn.hcs and rmally !O the: CJllc:rna1 kNod. [IS value
""'"
0.5 V for n.. taJ·jp'aphlic bruslles..
•
2.0 V f.. c.rllon brusIIeI..
DIll
_wr ""
Ko.-.,I<· 1.6J. ".fiutn1IltM""'" d#lj'~n 450 iI. at 1JlJ V ond /,.,. I'I'JUIatt<'<' of1M ~Iut", ~Id 50 n oM 0.03 n rup«/I.-rf". C"kklaJ~ IN ,.."""IIN ~.",", ~1"", Oeocnuor
{,~
Cunatllhruuab .......1r..ld """"lDI il
..
{", .. Loood cum:nl . AmIaIUtl! AmWuft:
2~
.. 4.6"
/ .. 450A
="'._
f .. f,. .. • 'iO. 4 6 a 4.54.6"
,,,II..,., dn:op
J.,R• .. "5-1.6' 1.01; 13.. \'
c
•
{ ....50" , -~
D.C. Gen&nllota
913
E• .. tcnnmal voltage + armature drop
• v.
'/I.
e.m.f. g~""rated in the armalure E," 230+ 13.6. 243.6 V hlUllpl~ Z6A. II. /ong· jh" nl compound g~""rolor ddj~rs a /qQd c""~nl of 50 II. al 500 Vond Iotu ~"""I~"'. sen.s JitIJ and skun{ field ~.i'lanus of 0.05 a O.OJ {l and 2.50 {l rt:
IJh" 2A I., .. .'idtng i~
.. SO+2.S2A \\;)111ge drop on oeriel; f,.ld wiooing .. 52,.0,Q3.1.56V Alma".", vo11l1ge drop 1/1• .. 52 X O.OS .. 2,6 V Drop at IlrusI'Iel .. 2 ,. ( .. 1 V
E, • V. Ill." ..rio drop .. boIs" drop
•
FIg. 26.47
.. SOD. 2.6+ LS6+2. S06. (6' £"""'P~ 26.5.
II. Uwrl-.l/tun/ rompounJ g.~Ttl1or
Iwu om"""".. u.usfidd and .muu·fidd rnim.lnus of 0.05 a 0,3(} nand 200 n "'.ptclively. C"lcu/<Ju fh.
30 A -- ----
•
Induud ~· ""f and 1M anna/"", cu,,,,n'. 11./1"", 1.0 V ptr :0.3 "nak for CQI!IQ("I drop, (.IL\ Ui: Stt. B. Elttt. 'Iachina I9'!lU Soililiool. GeJ>Cf1lI<Jr circuit di.ogram i. mown 1I1 Fig. 16.48. \O;>Itage dror in ,rn.,. winding .. JO " 0.3 .. 9 V a<:ro5S shum winding . 220 .. 9 * 229 V 1. . . 229!lOO _ !.l45A • :10+ Ll4~ _ 3Ll45A • 31,145)1 0.05 .. 1.56 V • Brush drop • 2xl .. lV • V+""';os drop .. brush drop + 1/1. • 220 .. 9 .. 2 .. LS6 _ 2J2..'i6 V F.um .... 26.6. In I> Irmg-JhuIII romp<mnd ~m~","", 1M 1"",Wll ,vll"", "lJO V ,.·hm g
".>V
\0;>1.
)
'.
'fl.
,•
,/oa,
SulOtlll1l.
l", r 2 :\U192 _ 2SA I , . J5(I +
~.S .
(5 2 .S A
I
914
Electrlc8l Technology /./!XJy
•
0.011 n
•
Sincexriet f .. ld =i--=e and divmorlUl~ !Mir combined i. _ O.Q3x 0.0 IW.045 _ 0.01 n
"",.1anCe
at<: in parallel (Fil. 26.49)
Total annaIW'e """uil resisIarIu .. K 0,032 + 001 _ O.o·n n
__
~tagedrop
IS2.5xO.on.6.4 V
III \bIuo",,,,nrrwU!dby_ £, 230. 6.4 ~ ZJ6.4 V
t OAn n
K
(i/\ Thea] power generated in umalun: E~.
FIg. 26.49
_ 236,4 xI52.5 _ J6,OSIW
in arma~
(iii) Power 10M
I.R. ,. IS2.-,lXO.OJ2
..,ri<:.
__
,~w
,. 152.5' x 0.01 • 232W • YI.... 230 xO.OI • 575 W .. 230x ISO • 34500 W
Po ...", Iost;n fi,,1d and divt:nor Pown diss;paIrd in .hunt winding """"""" delivrtm III !<)lId
Total .. 36MI W. •:.nmpk 26.7. The lo/lQl<'ing mlont1llli"" is lor" JOO-Uv. 600--\0: 1"",·./r""1 compoulUl ge...,,,,,.,, : SI"tltI~/J ",ulanu. 7S n. a.......s~'" "Si.lanu ",elud"" hr..." ff.illtJtlu • O.OJ n. commulal,n, fi~/d ,,·,lUIin, ",,;mltlCt! • O.Oll t1 urit.ftl!ld rrsi.uuru .. 0.012 n. di'"t!rltN rr,ulance ~ 0.036 WMn IN 1Mrlo;N! u ik/i""';"glull WoJ. ""k,,/tzle 1M .,.,,',,~ tlIId poM'U p ....ra'fl} """"'"rr. lFJect. Eng- II . Pu ... l'n;,·. No.'. 1989) Solution. Power ootput .. 300.000 W Output currmt • lOO.0ln'600
"
,~n
n.
by,,,,,
•
>00.
•
~,
""'.
~
:?: J
I
T""
rnis!anCC and djV1!nor ",.i. 1M<><
_= "="
•, 0.0110
,
'-
'.I. . . SOO . 8 . 50SA • .,,'.~.
O.OI2C
O.oJC
_ 0.0090
• O.OJ - 0.011 .. 0.009 .. O.OS n 50S x O,OS _ 25.4 V
\\)Itage ~ by onnalW'e
600 + "l.5.4 _ 62H V
Power """"",ted .. 62!1.4 x 50S _ 317.100 W ,. 3 17.7 kW
26.33. Generoted E.M.F. or E.M.F. Eqoollon of 0 Generator Let
4> .. nlllIpoIe in weber Z ,. I(OlaI numbo-. of ~ oondox","
l,..J
~v
1 ,
= in pat:lIlcl (Fig. 26.50) !Mir combll..d
\\)Ita", drop ,. ~
I
•
FIg. 26.50
_ 6O(VJ5 _ 8 A.
SIIItt .... ~ fKId n:sistanoe is
l .. •
D.C. Generalon K
915
N". of 'IOU x NO. of <xm,h' l"Iorsf,1ot
P K No. ofgcncr'lllor pOI.,.
A N E
No. of p;>IlIllel palh. in armature """"tun: rotali"" in ,""volu,;"", per minute ( •. p.m.) ~ e.m.f. induced in any panllel path in annalu,""
K
,.
dt
AV'rage •. m.f. gencnoled/COIX!""-"'
volt ( ... n K l)
Now. nux cullcondu<:lor in one """Iuli"" d ~ tpP Wb No. of ,""volutiorul.< ttond K N!60 Hence. ~ng 10 Farad.y'o Lows of Ele<:trom:Ignclic Induction,
I'..M.F. generatcdlconduclor .. dd~
E
tI>:;'N ,.,,11
for a simplex wave-wound generalor No. of parallel paths " 2 No. of contlu<:1oll (in srnes) in on< path " :.
E.M,F. ~edlpath .. (l;PN 60
X
zn
~ tl>ZPN voI1
K 2
120
For 0 simplex lap-wound generator No. of parallel paths", P
No. of COIX!uc'"", (in ..
~ri<s)
in one paIh K ZiP
I'..M.F. genera.\edlpalb. .. tI>:ON
IDg.""""IS.""""lede.m.f.E,,,
",here
x;
K
q,::: volt
q,::; X(~)VOll
A .. 2-forsirnplex
w.~-winding
_ P _for 'imple.. tap-"inding
E, ..
i,. .(2:' )(I;Z (~) .. ~Z (~) Voll - Ql in f3d1.
For • given d.c. """,tune, Z, P and A ...., ron:
q,
•:::'a mple 16.l1. A ["" ...pol. _mlo" having ""a'''''''''wnd armal~u ,,'indillg has 51 .101•• e<JCh .101 ronJ4;n;"/l 20 rondllt:lOrJ. Whm ... iII bOk 10 I>c 7.0",Wb ? (Ek!ct. 'loclli:oc:§· l. Allalo.bIod l' ni~. 199.' )
SoiUll1lCl.
E• ..
tI>:::(~)VOlts
He....
K
7 x IO- l Wb. Z K 51 )( 20 .. 1020. A" P K 4. N K I~ ,-p.m.
E,
K
7Xl0-J)(~oo.OXI500(~) .. I7Il5 V
E:umple l1i.9 . An /l.pole d.~. g.~mlar has .roo """,,'uu condI
rE P. T.rnninll Lnh . 100 \1
•
91.
Electrical Technology
,
_O_03x~x20x l .
• S<Xl volts fot l2p-...·'ndml Ifil i. wave-woond. P • 8.
Ii
~_
rrn! pu conductOr.
Ne, oulpu' eurttn, _ 8 ~mp a.~ in Fig. 26.31 (al.
••
Powi:rOlltpllt • 4 kW ,., W.",,·,,-..und, j()() rpm : 2 groupo in parallel. OIl< '""'" Iw four coil' in .00-..... in F'3. 26.5 I (b). 1bLlI 1'''''''',01111'''1;' now
.mes. ..
,
• ,
<
' :-;"\11"! XII '
- .'
"
01 1200 !pill
.,...,.
, •...,
~
:IOOVoI..
5OOx2.IOOOW.
"
" .' , "
•
Ami"'" I Impaslbecur-
I.) Lap-wound. 1200 rpm : SOIl V p'" cool-group. 1\ group> in panllcl
" ,.
"
Hence, with w",'e-,,;n
... ddlllDaal .
"
,
_1. Pia. 4
E • O.()j x 500 x (NMJ) " 4 E • S<Xl ~oIts. N. 300 rpm
and
• •, ,.
•
Solution. With Iap- ..·""hng. P. a.8 E: • • (N1tiO) (PIa)
•
II i. rNlIC«IrO) OIl< fowth, 1><1"8 J'If"OpQ
FIg. 21.51(.0)
.....,. [":::::::::::::::-::::::::::;::,~~-:-.......
I2!iV
--
-....
, I ~ ", iI. .t", shu", ~ItUalor liar "" INiwud voIrup Oft oplIS. Find 1M /ood cur",nt if 1M field· d"',,;1 .... I.
.
,
Even thou", Ibe questton does no! """,ify some coodiOOlU. Ibe soilllion gi,.. n here i. baocd 01\ ro<m:C ........h 10 deal " 'jlll Lht c .....
,
A.o &howIl in
I~&.
26.j2 (~). Lht machi"" iJ ",n
A.o in Fl,. 26~2 (b).
aI H, rpm. E. _ 127.8.47 xO.o::! _127.L7 ,,0115 ~ ...
8 amp
O.C. Generators
917
Ii, can be 127.17 wit>. if m. .peecl i. ,nctt:a.cd to fl, rpm. .uch !hltt 8 .47
S,·Hfl,
~
SN,.orN, ... - , - N,.I.05875N,
,
Thu. the effect dlle to 5.875% drtte:ose in nux i, """'l'"n.. tOO by 5.S75% lncrelise in ,peecl.
---r.f'. 8.47
F
'
(a)
'.0
,
,"
"
~,') ~
•
.~ F,
,-,
127 V
"
a....moronno>-Iood
(0' Fig.
~main
om ~
.358.5 amp
358.5 - S .. 350.5 omp.
r,,,,,,,,,., u.. Il ' An 8."",~ d.c. ,hlJlll 8~"""""" wilh ns M'Ol'e-COIIn«ud """"'un ~ond""'O" a,w Tlln' ning a/ 500 r.p.m. 'upplia a load of J 2_511n$i"anc. al lu..",wl 'vlTag~ of5O V. n" aTmLlI"ft! ~i5'an~ i, 0.14 D and ,II< fi~1d ,..iWlIIu is 250 n F"ullh~ 0"""1",,, ~JI''''nt. 'h~ indJlCM ,.m.! /JI,d ,h~ flUX ~, pol~. ,E\o"Iri<'1Il £",' ·· I. BI ," ' ~~ l .. ,- , I ' 'io~ut;..n_ TIle drcuit i•• ho .... n in Fig, 26.53 LoadCurrull
.. VIR~25G'12_5&20A
Shunt Cllrrtnl • Annatun:: Cllrrtnt '"
Induced •. m.e.
"~.
.. ..
2~50~
IA
20+1 ~ 11\
• 25()+ (21 "0.24)
"• 25504 •
••
Loodc:d (]cOCfO.or
:ze.~
u ... he~ al 127.17 V. 127.17 ~ 120
'L
120V
~
U7amp
If f.', is ... umOO to
,
W.
IA
I,
I I, 0
~
0
~~ , 1 " I •. . =v ..
~
,
Fill. 26.53 g
155.11-1 \
<J>J: ~ (~)
",WI)
E mp _ II , A " _pol. Iap·NMnUI.d 0"""'"'''' of a d.~.•hunt g'M,afO' i. "'f/u;",d IU ...ppJ, 1M loads """,UI~J in pa",II~1 : 5 kWGtyse'a/ 250 v.1JIId 2.5 kW uglrlin& load aUoal25{) V 1M G",,,,,,,,, IrlI1l an annalJltr "'$i"am:~ ofO,? ohm and" fi,ld tr.is/anc~ of 250 <>hnu. 1M "rmallt'" has /20 rondW:ln" in I/le .Iot' ,,,,,I "ms al /000 rpm. Allowing 1 V /K' /m... /t for ~on""'t drop, =1 ",glutlng /riNion, find Fi'lA' pt, pol.. A"""IU"'-('"'''''' ~r pa'all~1 palh.
. 918
ElectricelTechnology
SoI ... ioo.
Geystt CUl>"l'nI .. SO£n'2SO .. 20 A C\uJt,nt for Lighung .. 25O(V2SO .. 10 A
Tb!aI """"nt .. 30 A F",1d Current for G<:nttIIIDf .. I A
H....,.,. ~~nl .. 3lA AJmll\lD'O ..,in.DeC dmp .. 31 x 0.2 .. 6.2 volts Gencr.w:d e,mJ. .. 250 . 6.2 + 2 .. 2!iS.2 V, since Ii .. V, + I.,. + TOI:II bluM conU<."l drop Forl4.poIe ~~ Npmmofponllelpallu .. ....mborofpolrs _ 4 ( I) The "WI per pole i. otuined f""" \be emf ... _ 258.2 .. I. Z NII5O!" (pia) .. I." 120>< l000i(0) x (414)
. """
m
.
• .. 129. 1 mWb per panoIlel path .. 3114 .. 7.15 A.
Annatu,," C\I~t •:""m..... 26. n. tI uparu'~ly r.u:itrd srMmu>r, "'ltrn ""111'''8 'If /OQ() 'p,"'- supplied 2QQ It aI 12j V. What ..-ill M ,/tr 1.-1 ,...""", wMn lit. qH!M drop. If> 800 'p.m. if Il u ""e/'MSN , OJ,,,,,, 1M' ,lor """,,,Ii'" IYSUIWIU .. Q,{}l oIrm tlIId bfldlo dtop .. 2 V. !OIl.4
"~~~~~:::':;::: r-~ , ' ,-~~ Al 800 I.p.m. E,>" 135)C 8OYl000 .. 108 V Ifl isthe ....... ioadc"",,nl. tbmtemtinal volt_ II" V;, given by
, • •
1.
~
'-' \f)f'I'---'
'01I
L _ _ _ _~I
11.. 108-0.04/-2 _ 106-0.041 :. /. VIR .. (106 - O.().II).'O.63S; /
~
159.4 A
I':u.n...... 26.13 . ..t 4·pole. 900 '-p..... d.<:. moc!tw Ittu" lentll"",1 ""'Iage of no v anti an
Indw:rd VO/lagr of U() Va' raiM .puJ. ~ "rmulu,... dr<:uil .."i.tllJ11U ,'~ 0.2 11 b 'M mar/u'fII: lJpt''fUinl .... a I"",""(Jr M a molor ! C"""""" 1M afJlllU"", cur",,,, and ,iI UNJ Iii
(Elect. M_hi ..... UIIE
s..:, B 19't'01
SoIullon. Since the induced Voltage E is nlOtl: Illan the !emlinal vol1age v, the machine ;. work· ,nl ... I Benera1or.
E - V'O Ill.. or 240 - 220_I. "O..1;I. _I(IOA E. _ ZN (PItt) or 240 . \0" 10-J " l x (900'600)(412) ; Z 'O IItXIO Smce there an: & tll11\S in I coil, il ""'InS tbete on: L61C1ivc conductonkoil. Hence, the number 0( coil • • 8tXXY16 .. SOO. £"""P~ 26,14, In" 120 V c~ VfII:_ 1M ""I.Jer:led iJS ri) IOIII-sirlUll and aJ (ii) sirort-IhlUll. H_ ,,'ill 1M ""'P<'~IIlf1U '" ,iI
D.C. Genenlton
In It
I.ont Shum (Fil- 26-'S (a))
SoIaIIooL (i)
I. . . IlUIl25 . 4.8A ; I .. 1001. ; 1." 104.111.
\bt .... dfvp in.rna"iD< 0.04.4. 19 V ArmIIun: voItoF drop • 104.8 >< 0.06~ 6.29 V
..
E. " 120.).19.6.29 .. I)()-' V Short SlIun! (Fig. 26.33 (r)) \u1I1'" drop in ..rico ..,;'>< 0.04 .. 4 V \u1\I.&e _ ......,. ",;ooin, 0 120.4.124V 0 124/2j . SA ; .. 1. __ 100.3.I05A
(iI)
..
vol. '. '00' , 3
Armat\Ir
'.
~
~~
drop
0
E,
0
lOS >< 0.06.6.3 V 120.'.4 .. I29V
'00'
4 .....
0
<"
'.
0.06 '
- '",.,
•
r\20V~ ~ J...
'00'
.~
1
0.'
'W,
-
1'{f
-
'" ...
61,
,1 ,.,
..ne, ...
When a divcrIC1" oro. I n i...,,,,,..:led in panolld ""ilb tbe iOO;I\I. the diapam b.comcs u 'ho"'n in ~"i •. 26.S5 (b). Ai pcr cum:nt·dividcr "lit, the eWTOnl throu&h the ..rie .... indina is .. 104.8>< 0.1/(0.1 . 0.04).74.86 A. II melln.\ that the ""00 field cu< 1001104.8 .. - 211.&'10. "".pl~ U,IS A f.pok. hM,.sJo-/ Jap-..Y>W>tI _ _ ~. 25 tW Dla serwlUllOl!iOh ..~ of JOO V n.....-..", ruisJ,,,.n is O.OJ MIll. Mriu ~/J ""'iJ ........ iJ QrH .... and ~foId ......,.",.... u- 100 ..... n.. bnuJt rlNpmll1~ 'aUro III 10 V [h'e"""""M
..mc:s ...
•
e.m.J. 1t""'IJ'ed.
!
C(;lk..Jarnrlw 1M No. ofcOtfdW:I",. ijlhnpurl is 1200 ,
'. _ 1.1.. _50_2.3 . S2.5A
Stnc:s ( ..lei drop _ 32.3 >< 0.04 .. 2. 1 V Annaru", drop .. S2.5>< 0.03. 1.575 V
Brushdrop .. 2><1 _ 2V
Ocnenlcd'<: .m.f .. E, • SOI). 2. 1 .. I.S7' + :2 . sos.67 V
-
920
Electrical Technology
Now.
E, .. 50$.67..
.~....m,*
26.16. It
~:: (~)
1')
0.02)(2)( 1200 60 '4 .Z- 1264
4.pol~ dc. " " ...
n..: "'-"m ;s ......,.,·..""'1Id mulloas '192 Co..aUClOrJ. "'/oat iJ: 1M I~aklq~ rot'JJid~,,' """uliool. Formula u>Cd
,
75i.J r.p.m. mId gmmuu on ~."'f. of 240 V 111M 1014/ j1w.lrom flKh pol, is QOUS Wb,
"''''_ ........... Wortins n"-'/pole.
..
4> x7SOx792 x" 60 2
41 .. 0.0121 \Vb: TOIal n""'pole .. 0.0145 \Vb
uili&<: cotlf>dcnt
£\lImplt 26. 17. A ~.poh. Inp-W(}fUId. J.c_ slum' ~"UOI'" """ .. _folj/.u pu pol. oI0.07 WII. 1M """"'~ ... ...",ding <'ORfis1J a{120 /wm.r Mr.h ojQ.()()4 n "'siJttDIu CJlc..lm~ 1M "","lIII III 900 ..1'..... if 1M ..""""",, nmN Is A. SoIIIIiINa.. Si~ uch lurn Iw \..." sidoes. Z .. 221l><2_400; N_900r_p.m. , ¢I . 0.07 Wb,/' • .4.4
.....m.,. "......
',,,,,i,,,,/
.so
E .. 4>ZN .I~)_O.01)(401()X900)(I').462''''11
'60),
60
4'
ToW ~i~ or 210 !Urn> (or 44() tonducton) .. 220 ><0.004 '"' 0.88 Q S;D«! 1M... an: " fl"'1llJel paths;n Res;",...,., of nch path .. O.ll8J4 .. 0.22 n Now, there an: roo,..uch res.isl.OtJlXli in parallel NCh of val ... 0.22 Q :. Arma!llre ~~e, R. " 0.2214 .. O.MS 0 Annaluredrop .. IJ?_50xO.OOS .. Z.7Sn No-,o.-,Imn. Da1 .ollll&C V .. E, - I)l. .. 462· :!..7S .. 45'1.25 .011. Eumple 16. IL A 4_pW. 1Dp--~ kM&·'Itwu, oLe. u""" oJ ,m~"- Nu MyfolJlou pt, poInJ/0.07 \lib.. 'n" a,../Mu wjnd"'l NfUts,. ' " 220 ,~nu GIld ,N rui.l......-.. pt, lItm ilO.OO4 DIuru. C(lIICllIo,.. ,iII wmoiMl ...,sILlS" i{1M rui.l"."".. ' " ,/iwll GIld J~~S r~/J art: loo oJrnu GIld Q.02 ohm.< ;:: . rt'~,j ...!1)'.- .. ,..... ~,..... pnt:""","""""';"1 (JI1/IkJ 'p.m. ..."h g _ ,' a""""'rt: c~,rt'nI of 50 A. A.I." ro/c"lalr IN powu <Ju'I"" III tW for ,..... Imrml
1ImW=.
III .... fJ....1. SIliutiGo.
E. _
~laoMIo
r-....,.... LIl;'. 19\1.\'
0-07" (220" 60 2) x 900 x I') 4 _ 462V
AI round 'nEl.. 2(i,17. R... o.os~n Arm. ",n:ul! resuunce .. R, +- R .. " 0,{}55 .. 0,02 .. 0.075 n AIm l;in:ui. """, .. $() " o.{m .. 375 V V .. 462 3.75 .. 4SR,2.~ V. w Fli. 26.57, I.... ~58,251100 .. 4 58 A . J .. 30- 4.58 .. 4~~2 A Output .. \IJ .. 4~~l!I x 4~A2 .. W,SI4 ....... :0.814 kW
,
I
V
,
~1
921
O.C. G&ne,atota £x:ab.pko 211.19. A ~p,,,''''dy nrilM d.c. p""""or. 14'Mn """'in! a' 1200 'p."'. ,,,,,plie. 20011. at 125 V w a e.n:ull<>lamstanJ ,,,,isrnnce. W!tat M'il/ he ,!t~ c~'rtll' ,.·!tin 'he ,!,ud is d _ d 10 I()(}() r.p.m. and 'he field C~Trtnt i, ",du.«d II) 8Q% ~ A""",uT<' ""iJlaNY!. 0.Q4 (J and '<>Ial dmp al brusMs. 2 V. Ig""'" .
'EI«I. ""d.j~ .HIIF Sec. fI, '9911 Soiutioo. We w,t! find!bt ,,,,,,,,,ued •. m.f. when the load cu"""' i, 200 A. E" ~ V. brush drop + [.1/. ~ 125 .. lOO X 0.1)4 s No.... E,,"
E,l
13~
FIg. 26.58 V. in Fig. 26.'18.
E., .. ";N,
£urn,. l6.2OI.,.
A ~-llOk d.c.•hun, gmero,o. "'i,k" ,lwmjidd rt!sisralla <>1100 a and all on11<Jlur<' ".ISlane. of 1 {J hos 378 ..m~~_-I.d cond",,·w .. in lIS GmI6luT<'. 11... flu.< {HI' pole i. 0.02 Wb. If Q loot! ,."ismllu 0/ /G n i, ccmtf"Clrd
'p,"' ..
It:lect. Tt:o:ltnoloit.•. II)dcrabMd l 'nl •. IWI ) :.o/uti..n. loouced •. m.f. in the genttalor i.
E,"
..
(~)
•
.nlt
0.1J2X)~XIOOO(1)
..
c
152VQh
8
•
I
1
,
'0
J
Now. leI V II< the lennrnal \,ol"'ge i.c. lbc ,'olr.ge available .,,,,,... the load as well '" the .hunl (Fig. 263'1). Load cum", .. \'flO A and Shun. cUrTenl ~ Vi)oo A
="taoc<
Y
Y
Armarurc cumru .. 10 + )00 · Nnw. V ~ E, _ . nnalun: drop
II \I
100
.c
:;: ~
fl<;J. 26.59
'"
252-lx 100
V", 227 volt
Load = n l .. 227/10 .. 22.7 A. P
K
5.153 W
~:""",plr 26-2:00bl. A /o14,-pole. lap-wOl'nd shunt gnt,rnro, 11m JOO (JftrI(J,u~'M"ducw" and aflux/polc <>10.1 Wb, II rIm.
922
EleclricalTechnoiogy
_ Due JO!IIe ~ III _ do:> _ _ w;1l t_1tdua: V.
........ (.. OIl dl'ecI 01 ~ .... _ rulhol. .. do:r......,.. IIM:opocd
T"~
r..Id""""" ....... II> otia:ht!yu~"'"
-r..ld-clro-o" ",........ "'&hIIY. Eumpk- 26..l1"" . JI 6-poI~ J<: gm""/o, "illS 01 1200 ,
_
".~_''''''''''',"" is J50 '"'" •• onJ '_m''''mI'''''''' thr ""Iiat 'u.~· llot ,In,"""'" U J mm. TI>t IUI4I t'~81h of 1M
lu,..
di~"""e'
~i'·g
f>tfd poIu aNI 1M ~/J
poIu is 261) 111m und 1M ~fd pok 4[n:tiW! """"ro~ i, ~ wlwlml frVt8i~g, If 1M ItaJ 96 roils """i~B J IlInII fH' coil and is -.....-rd dl4pla lap. mkwltu~ /. ) Jbu fHr pok fir) tjfn:riW! poI~ "rr/'''8,h aNI t~, ~ ~i'·gop flllX
""""tw,..
. \:.::~"'1'0.""-
!11m
I~
........"I!>.
"'.......
y
I--
tk,..iry.
SoIullon. (tI ) Z. (96)( 3)( 2.576. P. 6.JI. p)( pi ... .. 6" 2 .. 12. N .. 1200 r,p.m . ..
2jO.
"' ''S~'' I200 (~):
fig. 25060
.. ... .. 0.004Wb
!lr l Inner diamet ... of tho pole ~ c",,1e i. _ 350 • 6 _ 356 rum. S,nce tilt", an: 6 poIeI. tilt ...1 r..ld pole nux covuage i. 8O'lo of ooe-li.th of the pole shoe ciltlt. Hence, lbe .ffeni,.., pole an: Itngill io
,
,
.. '6)( Ild"O,g _ '6 "10K 356,,0.8 .. !49rnrn _ 0.1 49tJL (~l Pole surf""" ..... '"' pole oboe arc " axial length
,.
of tho pole (FI,. 26.60).
_ 0.149)( 0.260 .. 0.03874 mm! Au. dm,;ly B .. 0.043410.03874 .. 1.12 T
t;...mple l6.21 1 " ~ A 4.pck d.~. ~r%' "'im 1200 rotIdw:t,,"g~"''''''~J 250 vaIu .... ..,-. d",..", 01 5f)() rpm. TI>t poI~-.""", haw ~ iI
m ....rth l.r I "I ... N.... 1972 & April 199tI)
Sle-arta. Me"" nux d<nsilY in the air-IIIP .. (O.OZ!l)o'(J8S)( 10; .. 0.65 Wb.'m'
Esamplo! 16.l1 lC ~ Afw"pak Iap.~ de ~lwnl ~_mlOri"...in~ 80~/4u "'im IO~_ sloI P""roJ~~ at _Wad "" u ...f. of MJ() ,,~ at I()()(J rpWI. Huw "'iII JO'I oblIQ~ of 210 V ! I 'agpur l uh ....",. 'uftllllN'r I " .)
v.
lOff 1M'
"'"
SoIu' ..... (il K""1'lIII openti",.peed ~ 1000 'pin only. ch.n~ 1M n UY pn .... The O.c. e.m.f. is liv.-. by E • (. ZN/60) >< (P/~) I'or lht ,iven opcraling Conditions. 400 .. . ,, (80)< 10) >< (1()()Ut(j()" (414) whichgi-;e, . .. 30mWb When speed i. kepi consIanl at 1000 """ only. Or to F1220 V on O.C.,
,
-.
., .. (22('L/400) 10.10 mWb _ 16.5 mWb
D.C. o.n.r.lono
923
Th .... by ;ncrt~n& tbt Ih",,,-fI(Jd-i:in;uil res.i_ willllhe help of addinC e,uem.1 rhcoslaiic, !be ~/ll in IlIc flCld-i:iJaJil il dccrused so as 10 Ik<:rcue \11( n""to 16,5 mW\>. liil Keep .. rne nux per pole, chaDge IlIc .peed. is heldronslanl III 30 mWb. on D.C. c.m.f. of220 V is obtained Ill. speed of N r.p.m .. £ivtn
If.
220 _ lOxJ(1-'xSOOxNl6O. N _ 5~rpm AI 220 V, lhe nWl can be "",,,,W/ICd .. 30 mWb prt.. idcd!he fl(ld nlf"fttIl
4OOIR"
II; IIDdsaJ1~.
- 200IRn
or R/l - 0.~5 R" Thus. !he f .. ld ciJaJi, ~i'lIInce be m.l1lCed 10 the new value of 0..'i5 R" in otdtr 10 ""'a,n 30 mWboffl ... per pole (rom. YOI~c of 220 V.
mu.'
I;;" Ally DIller combllwKxI of proper speed and nWllpole can be c",*," and worked 001 on "l1li1 ... 1111($.
2'-2114,. A Jhort·J~II~1 d.c. t:""'fH1WId Iftllualor .upplitJ 200 A aI 100 V. "INc "'Ju, 0/""""1"",. uriu ji.ld and J~unt jitlJ wlnd/IlIf' ,,'" 0.04. o.OJ and 60 ohnu ""p«fi,·.Iy.
~'""",pk ImIU
Find 1M • .",P"Ufltu AIs" find 1M ~.", Ifmnated i l _ mochiM is ctHIIf«l~d
.............. Willi short·,hum coonccUon. """.. n in Fil- 26.61 (0). V. " annal"", IerIrIIrW vnl!a.gC .. 100 (200 x 0.00) .. 106 V Shun' f.. ld currem .. Hl6i6O .. 1.161 amp At1lI3'''''' """"01 .. I. _ 100 + 1.767 .. 201.767 amp Annal"'" induced c.m.f. .. 106 + (lO1.761 x 0.(4) .. 114.07 \IOIu
, ,--~",-",~-. .
".-= ,--f fF1767A
Q:
,
"'"
I
...... (I) 5Il0l1-10',,,,,, COIUlOCliooo fig. 2Ul('"
Nnw.
w,," 1on,-$hunI coo"""",,,,,, shown in Fil- 26.61 (b). Shunl field
~nl
.. lillI6O .. 1.667 amp
Arma"""CIlrrenl .. 201 .661 amp TOllII vollllge drop in orma""" and50ries fICId windi", .. 201.661 (0.04 + 0.03) .. 14.12 voIu Armature "xlucod c.m.f. .. 100 + 14.12 .. 114.12
""'*
\1011.
'''''' In ""'" of :ItIu", ofI shun. eIII (... Uwn! r",1d ""'-"lie ...... ....) ~ boo ~ '" Jt1 "", •. m.r..• J'
924
Electrlcat Technology
t.Dml* z..ll
A
,
'-8 PuMr/.A_ ......
"""Itw/
""'1'" 1000 ,p..... ntppIj~s 10 ~ W "''' ~ '" 210 '" TN "'s..~ '" ".-,,',... "/Kid. -.I ~nafk/J",..0.04. IIOtlttll(lOS tJIom "'spt'(''''''/y. o."roJl _tJk"rI':1 '" IN ~ /ofIIi Is «J'.iI. ('! Coppulou. (u) Irtm WId fri~"011 lo,s. (iii) 7'<>",..., d""IQfNd by 1M P""" ""'YO'
f',,..
"
,•"
"
(Amra ...... l "h~l) 1,",1
s...,-
'l'
U>ad ~dl ..
"
FIg. 2U1(hI
'"000 .90.91 ...." --no-
I • .. 92.9 1 &,nl' Input I"J"I'Cf .. W.oc&O.85 .. 23529 ","," Tutallooseo ,n 1M mad .. "" .. Input - Outl"'t ~ 23529 20.000 .. 3~29 ",,,,n, (II ('~r "'un-: 1 Power """ in oenes rleld· ... ,nd'''II + ""',aU,,... w;np<soes .. m . 400. 1217 .... us /u'mIII\IIl\=m,.
hil Iron lind friction I<><soes _ Total ..... - Copper _ _
.. 3529 - nl7.Z312"''MIi 'Uil lei T .. T~M\-'dapod by II><: prime.mover Al 1000 . p.m.. an",l .. . p<"ed. (IJ .. 211 )( 100IWi0 .. 104.61 nodho<: TX
(IJ
..
Inpln pow.r
T .. 2lS29ll04.67 ..
22~.~
N",'
In
26.34. Iron Loa i'l Arrnat\a'e 0... 10 Iho mwiooD 0( llIe iron ron: 0( Lhe &rma1ItrC ill II>< mopdIC n ..... 0( llIe rleld poIco. tboR . . """'" ~ takulg platt rotIlJduoualy in !he ron: and ... o-n as I"", Losseo or a;.., LusstI. Iron ~can>J>' 0( (il H,-...rai> lou and liil }:ddJ ClorTftlOl lot.s. (il 11).'...... '--111.1 11Ii. 00 ;1 due 10 ,he .-eve....1 of of the. '"""-'."'" 0,,", every portion 0( the ruwin. rot1'~. uoo.. N lind $ puk .hcma'ely, thereby .U""''''' $ II'" N poIorily respeotivcly The run: "'Kk'l""' one: romple.e c)dc of """""ire reversal aflCr pauil/a ~ ont pa;rof polu. If P is the nu,nbeJ of poin lind N. the a/lI\a1ute ,\jlttd io •.p.m .• II>
"",,,,,Ii,,,,,,,,
,n.aI.
j _PNII2(J
The loa depends uJIDII the .oIu.... and
cr-Jc 0( iron. maximum value ofn... d=.ily B_
frequmcy 0( m1JnoUc ~ • . fa- IIOf'I!>lI n ..... d<m;1ir$ (i.~ uplO Ii""" by ",rianlOU f..........to.. AonIrdin& 10 \Ius formula.
,
w,
and
1.5 WhIm' ). h};.(ft'eSrs .... is
D.C. GeneraIOls
925
Value of n for .
Good dynamo .heel .1Ce1 ,. S02 lion', Sib",," .lttl K 191 lim', Hard ea...leel_ 7040 lion', Casl Sleel. 750- 3OOOJ/m1 ond COM iron. 2700 _ 4C((J lim'. Iii) EddjCurftntl_(W) Whon lhe armature cort rol8l~'. il alw culS IlIc OJ.a&I>Clic nux , Hence, an e.rn.f, i. induttd in !he body ofth( cort :ocrordinllo !be laws of ~l«tron"'8"dic induction, This ~,m, f, t.hough small, up large Cllm'nt in lhe bodyofth( "ore due tn it> .mall ""i'lane<:, ThIS currem is known as eddy cUrrent. n.. power loss due!n Ihc n"w of thi' currenl i, blown as eddy =<>1 loss. Thi, I"" would be coosidOle is th .. W," f ool W, ~ f'. Thi, fact makes it possible I" scp.or~'e !he lwo los .., .xperl""",lally if so de. by Ihe ternpaalu", ri",. It.e.e Iosse!; have to be kepi as .mall as i5 ecouomiealJy posSIble. Eddy e~nt J""" is rffioced by psing 1.",inalw con: bul hysteresi, 1_ eannot be rffioced thi. way. Foo- rffiucing !he hy"""'is 1""",_ those melal, are chosen fOf the annaIure core which have. low hysteresis c(>efficienl. Gcne",lly _special "I,con .lttls 'och as .loIIO)'. are u.sed which not only ba"e • 10>1.' hy"o",.i. coeffICient but which also JIOS*" IUgb eJecrrical resisli.i[y.
..,1,
N
N
~"
'-
IS
S
'0'
'"
I.,..
26.35. Totollo5s in a D.C. Generator
n.. vanons lusses occutring in. gencrtltor can be .ub-divided as foUo,,',: (.til
(;oppcrL.-
Ii) AmU01UreCOJl!l"rlos<m/.'R. ['01. E:/. .. lhepowcrootpuifrom......nu..1 ,,-here R• .. resistance of annalu,"" lind imetpOle. and .. ries rleld ...~ndins etc. Thi. I",. i. abool30 to 4Q'l. of full·luod los ....
92.
~
Iii) Field coppe.-Ioos. In ...... case of "'un, gencn.lon, i, is ~ally mn<WIl and fJ.R.. (or VI.. ). In ...... cue: of ...rit5 £flImIlor. il i ... I..l R......1Im: R" is ~idaB" loss of rowing annature, n.e.e ..", abow 10 to 2()'l, of EL l..ouei. Tho 1OIa11oi!se$ in I d.c. lI"n«ator are sumnwUcd below:
8'_,'
--
-~-~~-
....
..... 1000.... _
26.36. Sh"ay Lones u .... Uy. rnagr>etlc: and medwticlllOU<:ll are ro!wlh-ely known as StnI.' WU~ . The:tc are also kno"m .. rocatlonaI Ioiocs for otwiout " ' - .
26.37. Constant or Stondlng losMs A. Kid aboye. r.eld Cu I.... i. """Slanl for shunt and compound genenlOl~. He!lU, O1",y Ios.se$ and shum Cu loss are coru;lan! in lheir case. n.e.c Josses are together known as Slandin, or """,tanl
. . . . W, Hence. for shUIll IIId compound gencnton.
D,C. Gen8flltors
927
Total I", ... ann.lu~ coppe' loss . W,_ I ,'R, . W,"(I ~ 1,,/11.•• W,.Amwu~ Cu los!; 1, ' 11., is known IS variable 1= beeau"" il varies with the load cun=L Total 10.. _ vsriobl. loss . ron5lanllos"", W,
26.38. Power Stoges Variou, powe, Slag.. in the Oa>l: of a d-c. ge"""'tor ..., .nov.'n II
...
-
'-'
~-
Frio:tio
Outpul of
Driv,n& ~
-...
,~-
~.
in~
F-I«:ui<
'"
~
. ~
,
.. VI Wall
..Il,] ......1
Following"", lhe three ",... rotor dfie,end.. · I.
M.d",,,iaol EIJ"",""..,y B
11--.. '" 1.
ge ... ratcd in annal"", n>o(;h'Il"caJ pow..- .upplled
lOla] wall<
",I.
~-
""1put of driving engi ...
Eleclrk"al EflkitlK')
11
_ C
~
waiU available in load cln:uit
'8 I).. _
101ai wailS gtnftalcd
~..XL
"sl,
,
C ..
It i. <>byiou.< 1h.at 0,", ... 11 efficiency fl. _ '1 .. x T(,- Fo< good ge""ral,,.... its val ... may II< as high .. 9~'lo. -; ..... Unless opeciro«l ise. «>rnm
26.39. Condition IOf Maximum Efficiency Go ......"" ""tpol ~ VI Gonrr;>lor input .. ""1put .. los..,.
.. VI+I.'R,+W,_Vl+(I . ',J'R, .W. (': 1, _1.1•• ) However. if I .. ;, ...gligible ascompam110 Joad current. then I,,, I (appmx.)
'1 _ ~ _ in!>'1
..
VI _ VI VI + I'll. + W, VI .1' 11., . W,
.~~~ 1+ I~+W,
, "
Now•• ffociency i. """,imum when
,-[~ +~) _Oor!!.. - ~ ~ dl V VI V VI'
or
1'11.," W,
Il.""". geo>enolor efficieT><"}' is maximum wheto '.riah~
10M!; _ mmIMDI I...,.;.
(':I.~I)
E~I
928
Tecll nology
"The loAd ~ ' ... ' ",,,..,,,,,mnllO maxonum
"WlfI
by tho ",1aI00n.
Vanau.on 01 '1 "'111"*1
==- i.
"r
shown in Fil- 26.63
1:amP'" It..U. A
lOll+: 250 V. tL~~ 6-pok.Ju.N,..,.,_ JOOO .p..... WMIf MI"~rinlI jiJl./oatL no.. amo/JJw" /Iou .SJ.I~C<Jttd""ro~ Fwll./oadC.. /ouu'O.6lal brwh drop is J >'01, lku""",," 1M flu~' pt>I,. N~II'«t ...... til
1--·
" -,~
FIg. 26.63
-"".", n<".... '.
(ElKt. bg." Lk<:tronlcs. M.s.
LDhJUa~
1M.
SoIU IIon. S"",e !hun' ou,,",n' is ""gligibl~. tho .. i$ DO $hun, Cu lou,
amllllUe OOlly I. " 10.00Clf230 _ 40 A
1_
.I;R.
Ann. Cu klu or 401 " IJI. drop _ 0.4)(40 _ 16 V ; Brush drop. 2)( 1 .1 V :.
(imrrated
NQ.t.
R._ 0.64" loJ; R._ O.4 0
E, " 2!iO .. 16 .. 1_267V
E._ .: (~)...,., :. 267 .. .,. ~~" 1000
"'.",pIo rrJiJlDIItY
,,-,n.f
E
no. oupperl ..... occu,.. in
m
.m.n.
JLl.iI41. A r.~"..rouw- tkuwn 19~ A llI/uminal p,d. of 250 V. 1M Dmo/JJIITr """(II'~~ our 0.02 D mtJ 50 0 ""1'«,; ... ,.,. TM j"", 4Itdfric'ioIt IMJI's
4Itd""""" MId I'WI
~/9jOW
1_/ £M. F IIr~",'rrJ 16, 0, UnMS Icl ""'p~t of tIw pn1tlt' _D, Itli ~~..:iuI. Wl«MniCtJI WId d«trlcal rJJklr"d~J. ' ~ltt1.
I.. _ Anna,,,,,, _01 ...", dn.>p ..
~ullon.(.1
"1
'"
Oencnlrd e.m.f A"",,,un:Culo.. Shun'CulMs TOIaI Ca lou Stray lou...
'10 rbIoK..... r. lIi"",u. ];"". l'lfl l
2500'50.5A.I._195 ~ 5.200A
I.R." 200" 0.02 _ 4 V
.. 250 .. 4
_ 1..~
V
.. I.'R._2aY,,0.02_800W
_ V.f .. _2$O"5.'2S(} W _ 1250. 800 .. lO5O" _ ~ W ; TOIaIIQues _ 2M() • %0 a 3q)O W
0Wpal .. 250" 19S _ 48.750 W; Inpul_ 48.7.50 .. 3000_ 511.50 W OulpULoIpnme""""er _ Sl .7SO \\
,JI Q(""t'aIOrinpu' _ 5IJ50W.Stny~ .. 9S0W EIeC1ric:.,!">'=" producrd in armaIur.. '" ".7$0 - 9.50 • 50,800 n~ • (.50.800'51.750)" 100 . 'l'lI.!'" Ek<:lrical or Cu I"""'. ~ 2050 W 48. 7.50 '1. - 48. 7.50 + 2.£00" 100 -
'I. -
(48.7~ 1 ,7 SO)"
!I!'.' ' '
100 _ !W.l'1
D.C. ~8toR
u.-.. l6.,2..$( •
•
A
j()(}
V. D.C
JJo~~I_dtaWs ..
l"", <M_ofJ _
,,~ ......"""'.. If 0, 15 ..... INId forld ....UIOlfa .. 100 oMu, Ikle"""'"
_ 92'
..... h,,,, u-I. if W ~inrcJ of IN
- - " - """''''1 III II ~_ dtl........., " Wad CIUft7J/ rtf «J II"'fJ IK......U..... l ,.;..-. l\ .... 1""
'MoI .. I ..... Ii i Au _ . o n ....,.. Jo.d.ouloC3 Ampsofl".. currmt. 2.5 Ampsart!""fUrn:d r.... rocld """,,ull WId 2.5 Am", art! requ'rN for focld ci=;1 and 2.-' Amps ..., ft1julrtrl for armature, Neglecling CI ol,.,nemar. SOD" 40 X 10-1 .. 20 kW Tout ~ II$. - " " " .. 12!iO .. r..,1d copper.Ioa .......... ""1'1'"'"..... .. fl2S0.12S0~42-JJ"0.U)...-.us.2.77ltW
•
29.
20 .. 2.771
"'OOE87.83'10
no
h~mplt 26.!li .... s hllnl ,~n""'/<>r ",.. Q ,,1.. .... rtI'nl <Jf 196 ... 01 v. TIw. ~Im~ 100us ~'" 710 W """ 1m. .h..mji~lJ roll rrsiJl.lJOC. is 55 n 1/ il lit,. a 1-:1... r1iJw",.-t. ,0.1;10. filld 1M load .... ,.,..'" e'''....p<>ndmlt 10 ma.r,m ..... 4fjril''Iry. IFledrkallb;lm""Il' Ptonjodl Lai>. 1'0<1•• 191111
OulpUl • 220)( 196 .. 43.120 W,., .. 88'10 COYUlIII elfocleD<')') Bec:tncaiinpul .. 4J,I3:W.8II .. 49.000W
TOIalIo5.a .. 4<).000 - 43.120 .. 5.880 W SbUlllr..,IdCUI'fWI .. 22G'Sj .. 4A :.I. _ '96+4 .. 2!XlA Shum Cu lou .. 220)( 4 .. 880 W • Stray Iol'"", • 720 W Corutrult I"""" .. lISO .. 720 .. 1.600 Armature Cu loss .. .1.880- 1.600 .. 4.280 W /'R • 4.280 W
~.
R: .. 4.280
at
R. _4.28W200 >< 200 .. O.IW1
Q
Fat lIIU,mumclflciency.
i'R• •
<:ClMWI'
~ _ 1.600 W ./_ jl600/O 107 • IllJ.1 "
"""''''.!: '" 1000 q.m. "'f'r'lll~!! I;W fIt" lrn",.-I 1M rrm-IallN"' at ~"""'Ik"', P,WII fi~1d and 1M Hn~-s Ji~1d ",.. 0.0$, 110 plld 0.01:1 a rr.P<'Cf"·~/y. T/rUJ".Y'roll ~"';'1Ir'J "'1m. "MY' lood iJ 88%. ";nJ (" I 0. lo",~. I.) ;"'"
...x",~
at 210 V
1!01e<-!. \"0<)11"".)· 1. K~"lIIlo.., l"nh 19171
\olulidll. ThI:!"nenI(l.- i. ohow .. In A" 26.64 I.. .. 22WllO.2A 1 .. 21.0II0(>..2(]. 100 A,
Dn:Jr in ~ ,_I
I• • 102 A r..,1d ... mdJn, .. 102)< 0,(16 .. 6.12 V
I;R.
~ 1021)( 0.~ .. '20.2W Serit> r",ld 1",-, _ 102' xO.06. 624.3 W
Shu"' fidd I"""
K
4" 110 .. 44Il W
~
J- •
-.
-,
I .'
• 1 , '""
' O0611
C< o ·
nOy
(O~ fig. 26.64
C
•
r
930 .
Electrical Technology
ss.u
'"
Total Cu Louo$ ...U(1.2. 624.3 • 440 .. I W CM",u _ 22.(XXl W ; iDPUI • 22.00M).&8 .. 25.000 W Taul klMeo .. ZS.000-22.000 ... 3.000W 1I'0Il and fn«ion los""" ~ J.(D) _ 1.584.3 ~ 1.4153 \\
Now.
"'"
T" 60
t:Dmpk~. It
• 25.000;
T ..
4.pibd.t:. g~_m'M is thhm"" 2QA laa /qaJ of 10
a
IjWQ"""'W'"
"""'WI« is 0.5 a 0JIl! I~ ,hum firld rt!';"lJna u 50 a rolru/lJIr t~ inJ~rd r.m/. a..d I~ ~ffi ~".u:y
of I~ mQ("",n~,
All"" ~ drop ar lVI'" Im..h. (.:l«Irinl T«hDl>lotu·I. Osmanla Ualy_ 19901 SoIuIlols.. T""".nai voI",¥ _ 20 x 10 _ 200 v
I.... 2OQI:50. 4 A;I. _W ." _204A I.R• .. 24 xO.5 .. 12 V • B~ dr-op~ 2 x I _ 2 V E, _ 200 . 12 . 2_ 214 \' . a, in l'ig.26.6.5. Si",,~ il'Oll and friction 1<>S5el .we not gi~ .... only ~kcoric~1
t
'"
efficiency of m. machiM can Ix: found OUL
ToW p(N/u gmmued in m. onnaIure .. 214xU ~~.IJ6 W UsefulOilIpul • 200 X 20 .. 4.000 W '1,. .. 4,CO:VS.IJ6 _ 0.n9
FIg. 26.65
or 71.9'K
f.umpk Z6.Z8. It I"",·,hwu ~-~'tJUNi 1'_lUlo' 81...,. Uf) ""lis lJI FL. _put of 100 It. 1M rt',islancu of .'tlritxa "'Intiinls of ,I" """,/ri_ am.all" " (Uorlwling brus" ('iJ,Uacf! 0.1 &s fi,,'d 0.02 n inul]l'Dle fir/d 0.025 n: .hunt fi.ld (i..clwlinl ",swialinl ",.illanul 100 n 1M j"", 10Sl Ql FI~ .. }OOO IV; "'Intingumd/nc,."" 10lSU lO,a} j()() W Cohill/< FL. rIrIe;'.u:y of ,I" mad,j_. ( .If,.-tr\c:;oJ M..:h i __ y.1. iQllon: \ ',,(,'. I~" )
a,.. _
n. ...
Outpul _ 240 x 100 _ 24.000 W
Total ...... lure circuli tt'l.0WI0t _ 0.1 + 0.02 . 0.025 .. 0.145 n
I", • 2ao.'100 .. 2~ A :. I. _ 100 . 2,"" Armature c;TCuit ~r 1000 _ 1 02.~1 X 0.143 .. 1.521 W Shun, field «>PPt' loss .. 2.4 x 240 ~ ~76 W lronlooo _ I(l()(IW ; FritIIl)l'Ilou .. :500W TOlItllou .. 1.521 ... 1.50(h 516 _ 3.591 W; " ..
102,~
A
,
2~.O::~597
.6.S7. 117 '
EDmjllr 26.29. In a d.c. """'hint 1M 'Qlal il'lHr IQU;r 8 kW 11I u, ",,,·,J.ptrd ~nd urj,all_ 1/ urilall"" "'''''''lIS Ih~ _ . hi 'pHd i. rt'/i"ad by n%. 1M IUlal,ron IruJ I. follnd 10 M 5 tW CalCWn,r ,"" "Jilt"";' and ~dJV CI<,,,,,,,laur. ~I fi! /"/I'I",,d (ii) ltalj Ihr ratrd .pHd. (Similar b'.. mpl~. J .. 1I)'d. rab8d. 20001
,,"t.
Solution. W.
Ita,'. ""'n in An. 26.32 thol
~/ and W._/' Since/. the: freq ... ncyof ... " .....10( n.. g.... liwion. is d.i=!ly proporIionallO tho arm.al~re .peN. W. _ N and W. " Itf
W.
O.C. Generators
931
W, ~ >I >< N ond W, " BN'. wbere II ...1Ii S an: con,talllS. W ~ W.+W.~AN .. BN' let lbe full raled speed be I. Then 8 .. Now. "'ben .peed is 75% of full rated spern. thon
~
5
>I >< (0.75) . 8(0.7S)'
... (;1)
M ultiplying (i) by 0.7' and .ubtracling (i.) from;~ we gel 0.187SlI .. I
:.
B _ J.(U875~ 5..JJ
>w Subslllu~ng
thi, v.J ... in (I) abov"
•
•
S.33 .. II
A _ 2.67kW
Ii) W, al ",led speed. 2.61 kW.
W,at raledspt<'d .. s.:ukW
W ) W, alhalflhr"ued.p«d .. 2.61><0.S _ I3J5kW W. III half tho rated ,peed~ 5.33 >< 05' ~ IJJlS kW F..xamp~ l6.JO. ~ lry'lu",i, aNi ~dJY ru...-~nllMu. in ad_c. maclri_ ""'!ling at WOO 'p.m. al'l' 250 W and 100 W 1'l'.~~'i,..,I), lj'''''fl''-T ",ma.,.. ''''"'''anl. ",ha • •'P"~ ..'illi:>e tatal 1_ lone. be halnd? IElcctrintl M""hiMS-l. Gujarat Unh. 1989)
o.
Solution . T",. 11oss
w .. w. ~
W. .. W,.AN .. BN'
250W
c.
Ax(I{l()(ll(i())~250;
W, z 100W
..
Bx(I Q(l(lI60)'ElOO;
A ~ 15
8~9f25
Lei N be the new speed in r.p .•. at which 100aiioss is one half ofllle loss at 1<XXl I.p,m. New loss zP.50.IOOVZ _ 17SW
175 ~ I'N.(9f'..5jN'
or 9N' .. 375N-4.37Soo0
-J1' ±)37S1 + 36>< 4.37S 2><9
"""'- It ""'Y be -..I tIul .. II>< "" .... sp<ed,
..
-37S±546 18 .95 •. p,s_ S70r.p.rn.·
w• .. 250 x (5701100) .. 14~ W 0
100 x (S7{vIOOO)'
.. 325W T:lImple Z!i..l l , A d.c. IhUIII 8~n~ralor hllS a/ul/lood t1U'P'" of 10 lW at a InmUlOI ...,iI"8' of 240 V. 1'/1, "rmolu", and 1M sh""'fi~/d ..-inil"'8 "s;"t.".,,~. (He 0.6 anill6tJ ohms "'1~c'l\'dy. 11u! ."'" of'M "'~htmit':,,1 a..d """,·Iuu,. if .m If. C"Ic~4J'" I~ po""~' rrquimJ.,,, kif. at I~ dri\"~8 .haft '" /1Il1100J. onil."" CfN",.pt>Nl;"8 rjfici~nry. INalWur LniHrsity Nnnmbrr 99)
Solution.
Field current ..
~;:g
.
15 ""'p. Ln:t.d c~nt
~ I~.:'
_ 41.67 omp
Armature current _ 41.67 .. 1.5 .. 43 .17 amp
~-;.W copper krsses .. 3
Po"..,. in"", ., !he ,haft. 11.978 k W EJrlti.""y _
•
11~~78
x 100% .. 835%
932
Electrical Te<:hnology
E""m~ 26..11. A /""& .lwnl d.c. W"'PO"nd gDU!r%r ddi,"{'n JiO kW,., no v.
If'.
~
ruU~~
~."',f.
"
0.01 ohm. r" .. 0.W2 ohm. and Jhu~1 fidd ha. a of 110 ohmJ. c"kula,~ 1M ""I..., of II~ induc~d (Bha"'Lhiln-"l: .. i.~nltJ No •. 19971
Solution.
"'" 00
Loadclltl'ent .. llOx 1(XXY.!20 • "" A
Shunt f",ld <·UTn,m .. 22G'11O. 2 A Armature ctLrttnt
~
FI;. 211.611.
j(tZ A
' . + r.. • 0.012011m E. • 220 + 15002 x ~
••
•
.......
~
d.c, COfI"4lOU'"
(O.oJ 2)]
226.024 V
F..umple 26..1.1. "rIrL """"rUrt of 0 four·pol~ d.~.•hun, /!f!lUralor IS lap-wound and I,,,~rolu 216 V M'h~n "mning III 6IJ() ~p.m. Annat"'"' hal 144 ,10". with 6 ronilll'''Oni pu .101. 1/ ,hi, """"I",.. i" I?M'()Jjnd. M"""{,·M"IU~/M. find 1M ~.m ./. 1In1~"'Je
~
864
Ftt a Lap wlDding. nwnber of paralld paths in armalure .. number of poie,
In the c.m.f. "'IU3lion. Since
, -,
E • (' ZNIW) (pIa) f.. .. ,
7 .NI~
216 .. , )( 864 x
. ..
2~
600'~ ~
86-lOt
milli · webe ..
If the """OI"re IS rewouM with W8.~e""""nection. number of parallel paohs .. 2.
Ik""". 0,500 I.p.m.. ",·ith 25 mWb as the flu" pcr pole. the 0"11,11= emf
~
(25 x 10'" x 864)( 3Ont60) x 4f!.
.. 25 )( 864 x O.SO )( 2JW
• 360 vol"
~:xeension 10
Que: Comnli"nI uti
Ih~ annal"" <'II/pIII fI'UI'"'"
In 1M "m cau •.
SalI1Unn. As'umption i. Llull field . ide is .uitably modiflCd in the '''''~.
Caw (i) : lap-wounil Machine '" 600 r.p.m. Arm.>lu",
e.m . f. ~
216 V
LeI each atm3Ium-condu.c"" be r;oted to c!llT)' a clln"OIIl of to .mp. In .;mple IIp-wound machine., . ioce I four·""I. machine bas foor pars!lelpaob$ ,n arm.,ure. t(lla! IIn",I:u"" ootl"'t-alrn"nt is 40 amp. HeD<"<:. armalllm-outI"'L·power .. 216 " 40)( 10'" .. 8.64 \;W C... (iif : Wave·woond m""hi .... aL 500 r.p.m. ArmaLW'O
Due
!O
e.m.f. .. 360 V
wav~-winding, number of parallel pallLS
iII """'''u"" ~ 2
t""
o .c . Geoerlltors HcllCt'.lhe lOla) ann .......
""'PU'
~I'II _
933
20 amp
n...s. An-...: Elo:cIncaI 0II1pt1'po'fI-cr _ J60 " 20 l< 10-' • 7.2 kIN at.tn . ....... W,Ib:<arno f1u~ P<'f ~ lilt! ........""" P"""CI" _pdU ...,11 to. ill !he .,..,.,.,..um of thee Sf:U'd>... (7 .2I!l.(4) ~ SIti). ~'1U'tMt- C ......hlSio"... In caoc ~cornmon speed for CIlmpU'In, ElcctncaI OuIpul! ... ,Ib Arne mach ..... once lap-wound and nexl wlVe........... nd. ~ if no diff<mll'C in ,he: '''''' a.es. t.ap.woond mach"'" hu 10"'" ,oltage and highor""""Dl "hde the """'c·"",,,oo nuoohll'" hn higher volta", and IQI"", tUrrcnl.
ha1Upk:u.J.i. II 4-poi~. u.p·rotI",w~d d.c. 1tItICir.M hDJ ~n UrmaJUIV "wlmla of 0 /j ohm. li,,.,j ,''' drmaJltrt rt'siJlmlu of'''' ""1C1t.~ .., ,.....tJfUIdfor "".'~ .........,..,__
IIl lwthlar I III. . '0>". 1m, Sol"'.... A 4-pok bp-"',ndJ", Iw 4 panlkl pm.. in ...... un If i. iJ ~'O(Ir>d for """ve~ Ihe ..... woce at .... Ibc ,emmw I:w;:comeo (4 X O.IS)" 0,6 mm. a. il obviou. from R,. 2667
, " T.~"'7-'"
I
, 4 pull"'l poth> (Lap-wlf'ldn,,)
2 panillel p;lth$ (""Ye-" ind,nll:)
Power raltnll: " d ,,4 JIm""",,", fIeN,'ftII X and y" rl4
Jlmuance 1kI"'''"' ItI and N _ ,
(oj Lac>-"'indJ"II
(bl W."'-"inding
""""', ""'''II'' (u)" (21)" 4<-1
Morial Problem No. 26.2 " ' -1"'10. d.c ~DCBIl)< l\ao ............ """" >no."", "'Ill 792
""""""Ion,
Tht 11 ... P'" poIt'l
om 21 w\>. lkI<""'D< the 1J-.:l ..... hi.:h it """'Id bo nm to r
"'"..-..or;' ).
kd __ " -
1 UJ.l5'· I ' f:Itd. I._.~ I·......
001) "'1>. ~ ofl~<.p
t,w«./'''"
""':tooO....-. r.. p
A dc. F = - F=..........r. <1Lj:!O V. M
~
14J .u.n. Ji
.,
.... 'b.. d.~ . ..,......... !oM ... <.mJ. <1L 20) V
If "'"' """" " ~ '" ! 100 '.p,m on< lim< III< "., per poIt i, ~ to O.ll! 9 ....'b per pMo. ,,1\01 i. "'"'" 1110 inJDrftl •. m .f ? lllW \ '1
934
EIectnc.ITechnology
r"" .
5. eu:u.... "'" Iltn per poIe ...... n:d 011 MI·~ 50 kW. .I(I) V. 8-poI<. tiM) •. p.nI. <1.< ........ ,.,.......- ,"",," 256<,""'~""""'" in all
a. III< _
rICk! JaIM&n
.. Mop oil V ..
_.
"" fuU-
II. IU WbJ Caku .... "'" ilia .. a ~-poic dj-namo ",un 121_un: COfIdu<"", .......... '''1 SOC! V "h<1I ", .... ng lap "",,,,,,led (~) ...." " _ ,
..
.. lOw •.,. m. ",hen "'" _'un: i. (a)
h.)
~1.56
""""n,"
.. II' ~
.6-, -'111 ","loIIC/oy •
Go
on ......
l . A>I-p>Ir _ 1500 •. p.nI. t.. un: ..,,," \10 oIou ..... 6 """"""'" I"" JIol. Tho ~ perpDlr is 10 mWb ~ .... _ ..... un.f•• de. Grncnoor if the ....... . . . . . - . If tho ~ per _ .. 100 A. _ ........1octncaI ~ 1110 V. J2-I k"1
(~t ..... l
An 8-1">1< Llrl>-wound dc. J<1Ii< Is O.~ Wb.
,. A
1_'.-UOkWI
1"""_ .....
I IIJ-.V ........ fllll-_~ofIOOA._f.. Id~.....,.,of"(I ..... be 00D
A,.,,,,,,,,,..,.,.,.
lII.mO, 1lU'\ ,M..l AI 10. A """,·.Inn" oornp<>IInd de. Gcn«ator ..,~;... cum:m of 100 A at. voh'K< of Z20 V. If "'" 1d II 30 of .......... I>:Id OJill of .... :Im\II~ 11, lbiI.l~ \InI$II drop ill 2 V - ' .... inxI and fr'oroon ....... 0IDDUIlI1I> 1 kW. r,nd ~ of the WIllI
r..
a.
.... tho .. _ _ ._"'-f. ~I tho _ ...--1IOd (J) .... ..,......""..tfri
n.
.......
I~)
om
.... .,...,.. ~ of .... I""""'movtt
dn,.,,,, .... "I>-
1... 1 Uf.1 , .•• ) 1.t9!lltll- .<1 2-1.'" kll
w.a<\ I
II . A 20 );W. 44(). V. >hon-""""- ~ dc_ .. nrnuo.- .... a full·1oad les i, 0.4 Q """ ~ of .... oeries and WIllI r..hI< 0.23 (I and 2-10 n rupml'tly. <.lcu~ ,1M: oombintd bean", fric,;"". ~ ,"&< ond <""' . ..,... of Il>e ma.chi"..
....'IUI'IC<:
!ns WI II. A .....~ «>IIII""'nd. ttdclivcn. _ 111"<'" AI ..... 1.0 V pcr _ fo.- ~ do-op .
•
U. In. IIIJ-.V eompound ..nrnuor ..... "",.uor.. of""'_u .... d>w>! and tho .. ne< w'n,h ... on: 0.06 n Q.nd 0,0l (I ~iv.ly. Tho I<>od <.,...;... of 200 lampiI
a.
Find ,be IOIal
M",,_'...,..,
''''' I:!IU, 104A A (.IIZG.J I , 100U 'I IF~ lai,. I'~I I... ArmOIun: of. 2.poIc:. 2OC).V ............... 400...........,... and """ .. .100 <.p,m. C.sc.. ........ .... 'ul pcr poi< If"'" ""mbot of ....... in...,h r..1d coil •• IXlI). "'haI Os ""'"......,. valut cl .. m.f . - in <",h «>11 ... ~aIci"i "'" rlCld ,f "'" ~u. dies ..... ~ «>mpl«ely ,n 0, I 0« t U,VTt'. II~ 1_1 IU"" CoIctI .... duco:j ,n 1200--11.""
fl."
r..k! roil ..... to !hil flax mhK:"'lIto """ in 0.1
_. from ........ of doanrc of n....linka¥,
' • • "1 1Ilt.< . IZM "1
D.C. Generators
935
15. A l~kW. 530-'1. 16po1e ~"'n' at 130m. purruo. What ""'" boo 'm' and lind thr vclUlte. noBk<:"lli _ _ .-.;on and in speed.
00-_ """"tal
,lion..,
(R;Vi> GIm#IIi T...1ut.. L ..I.~ ll~"f'dl. 1_1 I o.~ ",'. 59.17 VI
,. ~
OBJECTIVE TESTS - 26 Tbc l=ic ""Iui""",ol Qf • d.c. o"". lu", w,nd· i". i, III.. i, most boo
,., '",<,
,.
"""""""',1<>1.
• <1OO
,.
,.,
.,IM (b) Ot (e)
A ,,,"v< "'·''''''"1
mu" ~o ., Ie..l oround II>< ....... Uf< befon: il do ... b.ck
..·h
,. ••
n..:
(bl ["'''''' •
,ide.
n..:
(a) mUllipl<.
Ie) full.p'ICb {d, pule.p'ln eq\I.Ol 10 • pOle I"l
,.,m" '"
comrnUIlI[<:4" bat> pu pole winding
,.,••
,,'
,.
di.lribul< ,I><
,<,
•
cool ~ of 180" (ck<1ncoll <nsw. "'" ObW" •
tI •• Illm'
w,"",", uniformly under
dlff"",., pules
'""
~.
\<) 2"",, II (0') 3"""11
~.
80 (b) 20 40 (a)
«)
(0') )60 •• . A 4'pOle. J2..1o! lop--... ""nd d.c. onn.alll« ....
'''''' "';I ...kk.woo. A.... ming .lngle lurn .oil, ODd progres.i,.., w;rd,nl.1hc back pilCh
"'' '1<1
•
... (~)
S (bl 7
(.'j
1
H . If I. ,.... ca« of I "",.,.in
wirwliol· (~) w.ve (h) lop
obtain. fu'l -pilch "'irdinl' In • 4-pol •• 35 slot d.c. ormatUf<. ck<:lricol-dn "'ill be obI.in«! •.-I>
,,.,.. ,
>ok: pu'J'O'< of. c"",muw"" in 0 d,c .
Go""""<:4" i. 10 (.. ) i"" ...... ""'pul v<>llq< (b) ~"lI at hru ..... (e) prov;"., _ "'lput (d) Ihc ,rduced , .c. ,nto d.c Fot. 4-p<>1e. H oyer. d.c,. Iop'W[nd,"lI W[th W.1oI> and """ OODduel<:4" per layu. Ihc "urn· be,- of commuwor "-' ..
(b) frxli<>rl.l-pilCh
••
~
rOO"". """.en
llIrice
(J) f .... ~mos J. d.e. annal"", ..'[ndini in wlUth rod if<. pol< pilell apan i«olkd ,... ,._., .. wiD'hng
"
(b) 432 «) 2 ' 6
OlIN
(e)
>rm'''.",
Tbc of. d.c. ,<""""<:4" Iwt. 2.1.y., lop-windin, houK
{<}
f""l<,
(0') "," I,ick""'n'
1<""""_
936
ElKtrlcalTec:hnology
IJ. "Tho _ r..1d ol • . " , _ . . . . . , . _ . 101 .. u<*d by __ ._.
-
16.. TIle ."""'....ial ~ff... ieocy of. III"'" P er.Mor;1 muunum ",hen il' variable Ioo!o
I,,) ...... 16) ....-.Ir)
lo0oi
(ot) ul<m.ll I' )a. d.' In< ...'",. til< ",,..,..1«1 .... f. I, dirr lht
<W'f"ICIOK. 1fl iI
Ie) ftu!llbet of ............, pmall.Jop-_4._.
,.-
(d) frklion and .. indaae 11. In ,moll d c ..... hi,.. •• "'''010", ,Iou or< 1OID01im<' n
oU"''''
(al rook! c...... n' (bl pole II ...
I~
....
("I axttiWU (1)) lInIy (e) ;ron
...... ~"""" .,., cal}'
0 c.m'II ollOO A
1'1>< taICd ain't_ of III" ."....... "
~
ill
(al qw< cr;,n) _ _ of ....
(_I 600
(G) ormat .....
(hi 1200 (d 1-100
(b) 11<10:1 (r) load
(ot) bn>,IIc.
1(; ...... H .T.I> Doc. 1_.
ANSWERS I. (0111 II· IGI
1. (b) 11. (,,)
J. (<"I 11 k)
~.
("I
1-1 , (bl
(bl 6. (bl 7. (<") I.. (d) ' . (b) IS. (d I .6. (a) 17. {dl .1. (I» ~.
.1. (bl
C HAP T E R
learning Objectives Armature Reocllon .. DemoQnelisInQandCrossmogneltslnQ Conductors .. Demagnetlslflg AT pe r ~
''''''
.. C'oss-mognelisrlg AT per
""'"
ARMATURE REACTION AND COMMUTATION
.. Compeosal1og WIndIngs
.. No
01 Compensat ing
""""""
.. Corrvnutoflon .. Value o f Reactance V""",,, .. M e thods of Impfo'{lng Commutatlon
.. Resistonce Corrmutollor1
.. €MJ Corwnulotlon .. Inlerpoles 01 Compoies
.. £quollslng Connections .. F't:YoleH)perollooolShunI ~ators
.. PoroleWlgDC.Geoe!Olor .. lood ShorIng .. Procedure for Paralleling DC Generators
.. Compoi.rId GeneratOl$ \n Poiallel .. Se rl e, G e nerotors Porollel
in
... Arrooture re(lCl iQn is tke change in t h ""ulro l pkllle: and Ihe react ion of t hO!.l!I09ndic field
938
27. 1
fllllCtrlcel TlIIChnology
Armature Reac llon
By Irm.lun: "",,,hon i, ~anl lhe .rr""l of magnel'" rocld <el "p by amlalU", cumnl on the diSlribuuon or nux under main poles of • ge...,.,.lor. lbe arm.lU.., magnelic neld has two effocu : Iii I. tI'_r~'Iis ... or . ,.urn.· ,h.ltUlinflux and I;;) I. >S·_r ~ .mts dost_ il. n,., Ii"" elfcc' Icod. ", rWl>C<:en then:" 110 cum:", '" the """du<'Iou,h lhe fol· Io.. in, rrmark.! apply to mullipolar rlelds lU ,,·.n. MQn;.,,'«, the b<ushc> "'" >ho ..... loud,. 'hi lhe annalure condUCIon din:ctly, Iltl>ough in pn>eIicc, lhe)' louch COInmUlOIor "'g~nl" II" secn mal la) the d"tnl>u,<"(! .}'mmclric.lly " 1'18.27.1 the hne JOinIng the ",ntn:' of NS poIrs, (b) 'flo: mag""'i" ocu,,".1 axis or pi""'" (MN.A,) .Qi""ide. with the g....... ""'a1 neutral lUi, or pi .... (C,NA) Magne11C neulral ni. may be defined as the .. is 01""8 "'hieh 110 e,m,f, i, prod""W in lhe &mI:l"tn: condOCl | 