Nivus OCM PRO CF, Инструкция по эксплуатации

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Instruction manual
OCM Pro CF
®
OCM Pro CF - Rev. 09 as of 07.06.2016 page 117
P-Factor The proportionality factor indicates, to which degree the regulating time is going
to be affected in case of a deviation
∆
w from setpoint w . The higher the
proportionality factor, the longer the regulating time of the slide valve at the
same control deviation.
Fig. 9-82 Assignment of P-Factor
Cycle time
The processing interval of the controller
Fig. 9-83 Setting the cycle time
Short intervals will accelerate the control behaviour, however are going to result
in oscillation of the control circuit as from a certain point if there are longer run
times between regulating unit and the measurement.
A long interval is going to reduce the oscillation tendency of the controller but will
however increase inertia of the regulating system.
Programming guideline:
Interval =
average flow velocity
x 1,3
distance between regulating unit and measurement
Control deviation This parameter defines the permissible setpoint deviation of the control system
without a regulating event is allowed to be executed. The setting reduces the
oscillation tendency of the system. Due to hydraulic reasons volume
measurements are tending to fluctuate around values. If there is no setpoint
deviation tolerance defined, the system will constantly attempt to exactly adjust
the actual value according to the setpoint. Due to this reason the regulating unit
might be driven permanently which may result in mechanical defects or higher
wear and tear.
Both values have an AND relation between each other. Normally it is sufficient
to define a percentage value here.
In case of external setpoint control (example: channel network management or
channel network control systems) and large controlling ranges it is helpful to
enter an absolute value as otherwise in case of low setpoints the permissible
control deviation percentage may become too low if considered absolutely.
Therefore the regulating unit will be tending to oscillate.
Fig. 9-84 Setting permissible control deviations