Mitsubishi Electric MELSEC Q Series User Manual page 84

3 SPECIFICATIONS
MELSEC-Q
POINT
Proportional band (P) is the variation width of deviation (E), required to change the
manipulation value (MV) from 0% to 100%.
With the proportional action, the relationship between the changes in the deviation
(E) and manipulation value (MV) can be expressed in the following formula:
(Kp: proportional gain)
MV=Kp E
From the formula above, the proportional band (P) is directed as shown below.
1
P= 100
Kp
Widening the proportional band (P) leads to the reduction of the proportional gain
(Kp). Thus, this reduces the changes in the manipulation value (MV) corresponding
to the changes in the deviation (E).
Narrowing the proportional band (P) leads to the increase of the proportional gain
(Kp). Thus, this increases the changes in manipulation value (MV) corresponding to
the changes in the deviation (E).
[Proportional band in the reverse action]
Manipulated variable
(MV)
Deviation
(E)
100%
Manipulated
variable to
deviation
Process variable
0%
(PV)
Current Set value
measured (SV)
value
Proportional band (P)
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