Automation Direct DURApulse GS4 User Manual page 520

Appendix F: PID Control
d
eFinitions and
The PID function controls the output frequency of the inverter according to PID calculation, which
is based on the deviation between target and feedback. The inverter adjusts its output frequency
to correct the deviation. PID can be configured for Negative or Positive Feedback.
n F
egative eedback
Output frequency increases if deviation value is negative. Output frequency will increase quickly
if the negative deviation value is large (Setpoint > Feedback). Otherwise, output frequency will
increase gently if the negative deviation value is small.
Please see picture below for example.
Max
Frequency
Setpoint
P F
ositive eedback
Deviation value decreases as output frequency decreases. This equals reverse acting control,
where controller output decreases as the process variable increases.
Positive Feedback means: -Target Value + Feedback. This is used to modify the detection or
deviation value which will be decreased by increasing the output frequency.
Output frequency increases if deviation value is positive. Output frequency will increase quickly if
the positive deviation value is large (Setpoint < Feedback). Otherwise, it will increase gently if the
positive deviation value is small.
Please see picture below for example.
Max
Frequency
Setpoint
Page F–4
i h -F
nForMation For igh
(Pid F )
orward
(Pid r )
everse
DuRA
pulse
Pid P
unctioning araMeters
GS4 AC Drive User Manual – 1st Ed, Rev A - 10/20/2017
Output
Frequency
Feedback
Feedback
Output Frequency