Eaton ELC-PB, Programming Manual

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E L C P r o g r a m m i n g M a n u a l
F o r m o r e i nf o r m a t i o n v i sit :
w w w. e a t o n . c o m
MN05003003E
3-264
1.5
1
0.5
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
PV=SV
K =10,K =8,K =0.2
P I D
Time (sec)
Application 1:
PID instruction in pressure control system. (Use the block diagram in example 1)
Control purpose:
Enabling the control system to reach the target pressure.
Control properties:
The system requires a gradual control. Therefore, the system will be overloaded or out of
control if the process progresses too fast.
Suggested solution:
Solution 1: Longer sampling time
Solution 2: Using delay instruction. See the figure below
PID
MV
D5
SV
PV
D1
D1110
0
511
0
511
0V
10V
0rpm
rpm
3000
D1116
0
255
0V
5V
Wave
A
Wave
B
pressure
meter
Pressure
SV (D0)
Set value
ramp up
MV
converted
to
speed
Voltage
converted
to
SV
Speed
converted
to
voltage
AC
motor
drive
280
0
0
280
250
200
150
100
50
t t
SV
SV
Wave A
Wave B
D2 stores increased
value of each shift
D3 stores the time interval
of each shift
Values in can modify D2 and D3
according to actual requirement