YOKOGAWA UP35A - Suppressing Hunting (Super2 Function)

8-30
IM 05P02D41-01EN
8.6 SuppressingHunting(Super2Function)
Description
The Super2 function suppresses the hunting effect of the controller without re-tuning the
PID parameters.
Hunting means the PV becomes unstable and oscillates around SP.
SUPER2 = ON
Hunting
PV SP PV
● Inhuntingcondition,theSuper2functionselectstheoutputfromprocessmodelasPV
signal.
● Theprocessmodelremovesafactorofdeadtimefromtheactualprocess.
● Therealprocessisundertheopen-loopcondition.
● Afterhuntingissuppressed,theSuper2functionselectsrealPVsignal,andcarryout
the standard feedback control.
PID control
SP
OUT PV
CPV
Process
PV
Process
model
+
–
EffectsofSuper2
SUPER2 = ON
SUPER2 = ON
Hunting
Hunting
PV
PV
SP PV
Load change
Temperature change
PID parameters are set at this condition.