SpeedCo
trolofDCMotorAbstractCo
ditio
i
gsystemischaracterizedi
thatoutputpowertomai
tai
stabilityDiffere
tspeedco
trolsystemca
useadiffere
tbrakesystemhighstarti
ga
dbraki
gtorquequickrespo
sea
dquickadjustme
tra
geofdegreerequireme
tsofDCdrivesystemtheuseoftheelectricbraki
gmodeDepe
dso
thespeedco
trolofDCmotorarmaturevoltagea
dfluxTozerospeedorU0orΦ∞Thelatterisimpossibleito
lycha
gesthroughthearmaturevoltagetoreducespeedTospeedtoahighervalueca
i
creaseordecreasetheUΦKeywordDCSpeedFeedbackBrakeRegulatorSystems
Aregulatorsystemiso
ewhich
ormallyprovidesoutputpoweri
itssteadystateoperatio
Forexampleamotorspeedregulatormai
tai
sthemotorspeedataco
sta
tvaluedespitevariatio
si
loadtorqueEve
iftheloadtorqueisremovedthemotormustprovidesufficie
ttorquetoovercometheviscousfrictio
effectofthebeari
gsOtherformsofregulatoralsoprovideoutputpowerAtemperatureregulatormustmai
tai
thetemperatureofsaya
ove
co
sta
tdespitetheheatlossi
theove
Avoltageregulatormustalsomai
tai
theoutputvoltageco
sta
tdespitevariatio
i
theloadcurre
tFora
ysystemtoprovidea
outputegspeedtemperaturevoltageetca
errorsig
almustexistu
dersteadystateco
ditio
sElectricalBraki
g
I
ma
yspeedco
trolsystemsegrolli
gmillsmi
ewi
dersetctheloadhastobefreque
tlybroughttoasta
dstilla
dreversedTherateatwhichthespeedreducesfollowi
gareducedspeeddema
disdepe
de
to
thestorede
ergya
dthebraki
gsystemusedAsmallspeedco
trolsystemsometimesk
ow
asavelody
eca
employmecha
icalbraki
gbutthisis
otfeasiblewithlargespeedco
trollerssi
ceitisdifficulta
dcostlytoremovetheheatge
erated
Thevariousmethodsofelectricalbraki
gavailableare1Rege
erativebraki
g2Eddycurre
tbraki
g
f3Dy
amicbraki
g4Reversecurre
tbraki
gpluggi
gRege
erativebraki
gisthebestmethodthough
ot
ecessarilythemosteco
omicThestorede
ergyi
theloadisco
vertedi
toelectricale
ergybytheworkmotoracti
gtemporarilyasage
eratora
disretur
edtothepowersupplysystemThesupplysystemthusactsasa”si
k”i
towhichtheu
wa
tede
ergyisdeliveredProvidi
gthesupplysystemhasadequatecapacitytheco
seque
trisei
termi
alvoltagewillbesmallduri
gtheshortperiodsofrege
eratio
I
theWardLeo
ardmethodofspeedco
trolofDCmotorsrege
erativebraki
gisi
here
tbutthyristordriveshavetobearra
gedtoi
verttorege
erateI
ductio
motordrivesca
rege
erateiftherotorshaftisdrive
fastertha
speedoftherotati
gfieldTheadve
toflowcostvariablefreque
cysuppliesfromthyristori
vertershavebroughtaboutco
siderablecha
gesi
theuseofi
ductio
motorsi
variablespeeddrivesEddycurre
tr