YOKOGAWA UT130, Техническая информация

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6-4
<Toc> <Ind>
TI 05C01E02-01E 1st Edition : Oct. 31, 2001-00
6.3 Integral (I) Action
6.3.1 Integral Time (I)
•
"Integral action" ("I" action) is a function that
will automatically diminish the offset (steady-
state deviation) that is inherently unavoidable
with proportional action alone. The parameter
that specifies how the integral action will
operate is the integral time (I). The integral
action continuously increases or decreases
the output in proportion to the time integral of
the deviation (the product of the deviation and
the time that the deviation continues).
•
Integral action is normally used together
with proportional action as proportional-plus-
integral action (PI action).
•
The integral time (I) is defined as the time
required to develop, when a stepwise change
in deviation is imposed, an output change due
to integral action that is exactly equal to the
change due to proportional action. The
longer the integral time set, the slower the
change in output; the smaller the time, the
faster the output changes.
•
If integral action is not to be used, the
integral parameter is set to OFF.
•
Integral time (I)
UT130: 1 to 999 sec or OFF
UT150/UT152/UT155:
1 to 3600 sec or OFF
I
Parameter Range
P=100%
Ouptut =
P
100
e +
T
1
I
兰
edt
e : Deviation
T
I
: Integral time
Deviation
Small integral time
Large integral time
Output (%)
(On-time ratio)
Output change due to I action
Output change
due to P action
Integral
time
Time
6.3.2 Tuning the Integral Time
•
When I action is OFF, change the
operating parameter "MR" (Manual reset)
to remove the offset.
•
Shortening the integral time, like
narrowing the proportional band, will
cause the measured temperature to
begin oscillating. However, oscillation
due to integral action is characterized by
a longer period than that of oscillation
due to narrow proportional band.
•
To manually adjust integral time
•
The main goal is to reduce the offset
•
Adjust from longer time to shorter time
•
If you see an oscillation at a longer period than that seen when
proportional band is too narrow, then you have made the integral time
too short.
MR
Parameter Range
PV
Time
SP
¥
If I is too short, long-period oscillation occurs in the measured
temperature value.
UT130:
-19.9 to 99.9%
UT130 (heating/cooling type)
and UT150/UT152/UT155:
-100 to 100%