LSIS XBF-DC04A - Page 553

XGB Analog edition manual
15 - 4
At this system, we assume that the PID parameter is specified as shown below to describe the PID control
operation.
Items
Value
Items
Value
Output temperature of
heating system (PV)
0℃
Proportional coefficient
(K
P
)
5
Target temperature (SV)
50℃
Integral time (T
i
)
3s
Cycle of operation
0.01s
Derivative time (T
d
)
0.19s
<Table 15.1 example of control of heating system>
At this system, if we assume that target value of output temperature is 50℃ and initial value of output
temperature is 0℃, SV and PV becomes 50 and 0 respectively. In case of this, PID controller acts as follows.
(3) Proportional control (P control)
In the proportional control, the controller yields output that is proportional to error.
Manipulated value of controller by Proportional control is as follows.
(15.2.8)
(a) If P control starts, output of controller by initial P operation is as follows.
200450
0
MV
If P control is executed for 10 seconds, output temperature will be as table 15.2.
If this is expressed with graph, it will be as Figure 15.2.
Time
Target temp.
Proportional
coefficient
Output temp.
Error
0
50
5
0
50
1
50
5
44.98
5.02
2
50
5
53.08
-3.08
3
50
5
50.15
-0.15
4
50
5
48.42
1.58
5
50
5
48.28
1.72
6
50
5
48.44
1.56
7
50
5
48.49
1.51
8
50
5
48.49
1.51
9
50
5
48.49
1.51
< Table 15.2 example of Proportional control >
PP
KEMV 