DER2 digital regulator instruction manual - rev. 02 - pag. 23
1.3 Slow voltage variations
In the event of rapid variation of the reference, a procedure of "slow" variation has been foreseen: in
response to a step variation, parameter P[18] determines the rapidity with which the transition is made.
A value of 1 involves the slowest possible variation; a value exceeding 100 involves an almost immediate
variation. The value 0 disables any variation.
2. Stability
2.1 Adjustment of stability
The regulator diagram is shown in figure 8.
K
P
K
I
s
Σ
Σ
+
+
+
-
Ref.
Feedback
Error
PI
out
figure 9 :
Regulator Diagram
fig. 7
16384
17742
P19
225V
230V
P18 = 20
P18 = 1
t
t
P18 = 100
Vo
The values of the proportional and integral gain (K
P
and K
I
respectively) depend on the position of the STAB
trimmer if enabled, or the value of parameter P[20] if the trimmer is disabled. The value of the proportional
gain K
P
also depends on the value of the P[11] parameter. The value of the integral gain K
I
depends on the
values of parameters P[12] and P[13] and, only for the standard DER2 with the STAB trimmer enabled, even
on the 50/60Hz setting. In the other DER2 versions, for example DER2/A (black box), the integral gain K
I
does not differ no matter how the 50/60Hz
setting is set.
The numeric elaborations carried out by the DER2 for obtaining the proportional and integral gain values are
given in the block diagrams in figures 9a, 9b and 9c
.
Trimmer
STAB
L[33]
Fcig
50
()
o/or/ou/oder
Fcig
60
()
L[53]
2
P[11]
K
P
2
P[12]
K
I
P[13]
L[54]
Fc
STAB
()
fig. 9a: drawing of the numeric elaboration of the proportional and integral
gain by a DER2 (standard) with the STAB trimmer enabled