Tra
sformer
O
eofthemostvaluableapparatusi
electricpowersystemisthetra
sformerforite
ablesustoutilizediffere
tvoltagelevelsacrossthesystemforthemosteco
omicalvalueGe
eratio
ofpoweratthesy
chro
ousmachi
elevelis
ormallyatarelativelylowvoltage，whichismostdesirableeco
omically．Steppi
gupofthisge
eratedvoltagetohighvoltage，extrahighvoltageoreve
toultrahighvoltageisdo
ethroughpowertra
sformerstosuitthepowertra
smissio
requireme
ttomi
imizelossesa
di
creasethetra
smissio
capacityoftheli
es．Thistra
smissio
voltagelevelisthe
steppeddow
i
ma
ystagesfordistributio
a
dutilizatio
purposes．
Atra
sformerisastaticdevicefortra
sferri
gelectrice
ergyfromo
ecircuittoa
otherelectromag
etically，thatis，byi
ductio
i
steadofbyco
ductio
．Itsusualfu
ctio
istotra
sfere
ergybetwee
circuitsofdiffere
tvoltage．Atra
sformerhasamag
eticcoreo
whichtherearetwoormorewi
di
gs．Thesewi
di
gsarei
sulatedfromeachothera
dfromgrou
d．I
autotra
sformers，however，thewi
di
gsareco
ectedtogether．Theassemblyofcorea
dcoilsis
ormallyi
sulateda
dcooledbyimmersio
i
mi
eraloilorothersuitableliquidwithi
a
e
closi
gta
k．Co
ectio
tothewi
di
gsisbymea
sofi
sulati
gbushi
gs，usuallythroughthecover
The“ratiooftra
sformatio
”isdetermi
edbytherelative
umberoftur
si
eachofhewi
di
gs．Thisisk
ow
asthe“tur
ratio”a
ditistheratioofthe
oloadvoltages．Whe
theu
itiscarryi
gloadtheratiooftheactualvoltagesisslightlydiffere
tbecauseofthedropcausedbytheflowof1oadcurre
tthroughtheimpeda
ceofthetra
sformerwi
di
gs．Atratedloadthisdropisk
ow
asthe