GE C30 Instruction Manual page 265

CHAPTER 5: SETTINGS
where
y is the process signal
r is the setpoint signal
w is the tracking signal
u is the regulator output
K is the proportional gain
b is the setpoint weighting
T is the derivative time constant
d
N is the derivative limit
T is the integral time constant
i
T is the anti-windup time constant
t
s is the domain
In discrete form, the equations for the regulator are
e k  
p k  
d k  
u k  

i k 1
where
T is the sampling time
S
AW is a flag which enables anti-windup
The incremental form of this equation is:
C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL
Figure 5-68: PID block diagram
r k   y k  
=
–
K br k   y k    
=
–
T
  
d
------------------ -    ------------------ -
= d k 1
– –
  
T + NT T
d S
p k   i k   d k  
= + +
e k   T
KT

S S
 i k    
+ = + ------------------ + ----

T
T
t
i
Du k   u k   u k 1 
=
–
Dp k   Di k   Dd k  
= +
kT N

d
  y k   y k 1   
– –

+ NT
d S

w k   u k    
AW
–


–
+
CONTROL ELEMENTS
5
Eq. 5-1
Eq. 5-2
5-147