Chapter 10 Analog Controllers
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Transcript Chapter 10 Analog Controllers
Princess Sumaya Univ.
Electronic Engineering Dept.
3442
Industrial Instruments 2
Chapter 10
Analog Controllers
Dr. Bassam Kahhaleh
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Error Detector
Voltage difference.
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Error Detector
Voltage difference.
Floating Power Supply.
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Error Detector
Voltage difference.
Floating Power Supply.
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral … etc)
Two-Position (ON / OFF)
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Two-Position (ON / OFF)
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Two-Position (ON / OFF)
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Two-Position (ON / OFF)
0
Vin > VSP
+ VSP
0
0
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Two-Position (ON / OFF)
VO
+
VSP
0
+VO
Vin + (R1/R2)VO < VSP
– [ Vin + (R1/R2)VO]
Vin < VSP – (R1/R2)VO
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode
Example (On / Off):
Level measurement in a tank:
Transducer output 0.2 V / m
Turn-on pump when level > 2 m
Turn-off pump when level < 1.5 m
Pump turn-on voltage = 5 V
VSP = 0.4 V
R1 / R2 = 0.02
VH = 0.4 V
VL = 0.3 V
VO = 5 V
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Three-Position
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode
Example (3-Position):
Level control in a tank:
Transducer output 0.45 V / m
Valve opening: 0 to 8 V
level < 2 m: valve = 20% open
2 m < level < 3 m valve = 65% open
3 m < level
valve = 100% open
Comparator output voltage = 5 V
VB = 1.6 V
R3 / R1 = 0.72
VSP1 = 0.9 V
VSP2 = 1.35 V
VOut = 1.6 V
VOut = 5.2 V
R3 / R2 = 0.56
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Floating
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode
Example (Floating):
Trip Voltages: 2 & 4 V
3-Position Controller O/P: 0, ± 2 V
Integrator: 1 MΩ, 1 μF
t = 1 sec
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode
Example (Floating):
Assume an inverter is used at
the output of the integrator:
Vo
1
1 sec
2V
-2 V
Vc
dt
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3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Proportional
p K P eP pO
V o G P Ve V O
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3442 - Industrial Instruments 2
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10: Analog Controllers
Electronic Controllers
Single Mode
Example (Proportional):
O/P Scaling: 0 – 10 V 0 – 100 %
Zero error controller O/P: 50 %
Proportional Band: 20 %
Error Range: 10 V
K
K
P
P
p
eP
VO
Ve
(
V 2 V min
V max V min
(
r b2
b max b min
x100 %) (
x100 %) (
GP = 5
V 1 V min
V max V min
r b1
b max b min
VO = 5 V
PB = 100 / KP
KP = 100 / 20 = 5
x100 %)
x100 %)
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Integral
t
p (t ) K I
e
P
( t ) dt p I ( 0 )
0
t
VO G I
V
e
dt V O ( 0 )
0
1/RC
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode
Example (Integral):
Measurement range: 0.4 – 2 V
Output range:
0 – 6.8 V
KI = 4% / (%-min)
4
K
I
4%
1 % min
( 6 .8 0 ) V
100
1
( 2 0 . 4 ) V ( 60 sec)
100
GI
0 . 272 V
0 . 96 V sec
0 . 283 s
1
RC = 3.53 sec
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3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Single Mode (Proportional, Integral …)
Derivative
p (t ) K
VO G D
de P
D
dt
dV e
dt
R2C
<< 1/R1C
R1 << 1/C
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10: Analog Controllers
Electronic Controllers
Single Mode
Example (Derivative):
Valve Control
Flow surge: minimum period 2.2 sec
Input signal range: 0.4 – 2 V
Output range:
0.0 – 5 V
KD = 0.04% / (%/min)
0 . 04
K
D
0 . 04 % min
100
1%
fmax = 0.45 Hz
max = 2.826 r/s
o = 28.3 r/s
( 5 0 ) V ( 60 sec)
1
( 2 0 .4 ) V
R1C = 1/28.3
100
GD
0 . 12 V sec
0 . 016 V
7 .5 s
R2C = 7.5 sec
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Composite Modes
Proportional-Integral (PI)
p K P eP K P K I
e
Vo G P Ve G P G I
R2/R1
1/R2C
P
dt p O
V
e
dt V O
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10: Analog Controllers
Electronic Controllers
Composite Mode
Example (PI):
Input signal range: 0.4 – 2 V
Output range:
0.0 – 10 V
PB = 30 %
KI = 0.1% / (% - sec)
0 .1
K
I
GI
0 .1 %
1 % sec
(10 0 ) V
100
1
( 2 0 . 4 ) V sec
100
0 . 01 V
0 . 016 V sec
0 . 625 s
1
KP = 100 % / 30 %
GP
(10 0 ) * 100 %
( 2 0 . 4 ) * 30 %
R2/R1 = 20.83
R2C = 1.6 sec
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Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Composite Modes
Proportional-Derivative (PD)
p K P eP K P K D
de P
dt
Vo G P Ve G P G D
R2/(R1+R3)
PO
dV e
R3C
R1//R3 << XC
dt
VO
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10: Analog Controllers
Electronic Controllers
Composite Mode
Example (PD):
Input signal range: 0.4 – 2 V
Output range:
0.0 – 5 V
KP = 5 % / %
KD = 0.08% / (%/min)
Minimum period: 1.5 sec
0 . 08
K
D
0 . 08 % min
100
1%
0 . 24 V sec
0 . 016 V
15 s
(5 0 ) * 5 %
( 2 0 .4 ) * 1 %
15 . 625
R2/(R1+R3)= 15.625
fmax = 0.67 Hz
max = 4.187 r/s
o = 41.9 r/s
( 5 0 ) V ( 60 sec)
1
100
GD
GP
( 2 0 .4 ) V
(R1//R3)C = 1/41.9
R3C = 15 sec
Princess Sumaya University
3442 - Industrial Instruments 2
10: Analog Controllers
Electronic Controllers
Composite Modes
Proportional-Integral-Derivative (PID)
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3442 - Industrial Instruments 2
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10: Analog Controllers
End of Chapter 10