gefran TPD32-EV-500 series - Page 292

—————— TPD32-EV ——————
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limit.Atthepowerupofthedrive,PI output PID acquiresautomaticallytheselected
valuewithPI central v sel multipliedby1000.
Example:IfPI central v 2 =0.5isselected,atthestartPI output PID acquiresvalue=500.
WhenEnable PI PID hasbeenenabled,theoutputPI output PID is,independentlyontheinputerrorableto
integrateitsvalueuptothelimitssetwithPI top limit or PI bottom limit multipliedby1000.
Example:PI top limit =2,PI output PID max=2000.
ThePIblockoutputwillbefurtherlimitedfromtheparametersaturationReal FF PID (seecorrespondingparameter).
Aspreviouslydescribed,PI output PIDisusedasamultiplierfactorofthefeed-forwardinordertoobtainthe
angularspeedreferenceofthemotor.IfthePIDfunctionisusedtocontrolawinder/unwindersystem,itsvalueis
inverselyproportionaltotherolldiameter.Whenwindingwithaconstantperipheralspeed,thefollowingisvalid:
ω
0
Φ
1
=ω
1
Φ
1
where:
ω
0
=angularspeedatminimumdiameter
Φ
0
=minimumdiameter
ω
1
=angularspeedatactualdiameter
Φ
1
=actualdiameter
ω
1
=ω
0
x(Φ
0
/Φ
1
)
Ifthedriveissetcorrectly,andω
0
isequivalenttothemaximumvalueofthefeed-forward,thenPI output PID
dependson(Φ
0
/Φ
1
).
Takingintoconsiderationtheinternalcoefcientsofthermware,itcanbewritten:
PI output PID=(Φ
0
/Φ
1
) x1000
Thisformulacanbeusedtoverifytheaccuracyofthesettingwhenthesystemisonworkingorduringthe
procedureforthecalculationoftheinitialdiameter.
Real FF PID Representsthefeed-forwardvaluewhichhasbeenrecalculatedaccordingtothePIcor-
rection.Itwillbecalculatedwiththefollowingformula:
Real FF PID =(Feed-fwd PID /1000)xPI output PID
Themax.valueofReal FF PID is+/-10.000.Ifthislimithadbeenreachedduringoperation,inordertoavoid
dangerouslevelsofregulatorsaturation,furtherincreasesofPI output PID willbeblocked.
Example:Feed-fwd=+8000,thepositivelimitofPIoutputPIDwillbeautomaticallysetat
10000/(8000/1000)=1250.