Burkert 8693 - I Portion

170
Type 8692, 8693
english
General Rules - Appendix
2 PROPERTIES OF PID CONTROLLERS
A PID controller has a proportional, an integral and a differential portion (P, I and D portion).
2.1 P Portion
Function:
(4)d XpK Y ⋅=
Kp is the proportional coefficient (amplification factor). It is the ratio of the adjusting range ΔY to the proportional range ΔXd.
Characteristic and step response of the P portion of a PID controller
Characteristic Step response
Xd
X
Ymax
Ymin
Y0
Kp⋅Xd
t
t
Xd
Y
Proportional range ΔXd
Y
Adjustment range ΔY
Fig. 1: Characteristic and step response of the P portion of a PID controller
Properties
In theory a pure P-controller functions instantaneously, i.e. it is quick and therefore dynamically favourable. It has a constant control
difference, i.e. it does not fully correct the effects of malfunctions and is therefore statically relatively unfavourable.