AutomationDirect DURAPULSE GS3-2010, User Manual

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Proportional Control (P)
Default Setting: 1.0
Range: 0.0 to 10.0
The first parameter of PID control is Proportional Control (P). For a given process,
if the Proportional Value is set too low, the control action will be too sluggish. If
the Proportional value is set too high, the control action will be unstable (erratic).
Set the Integral Control (I) and Derivative Control (D) to zero (0). Begin tuning the
process with a low Proportional Value, and increase the Proportional value until
the system goes unstable (erratic). When instability is reached, reduce the
Proportional Value slightly until the system becomes stable (smaller values reduce
system Gain). Stability can be tested by moving between two wide-spread
setpoint values.
With 10% deviation and P=1, then PX 10% = Control Output. For example, if the
speed of a motor is dragged down 10% due to a load increase, a corrective speed
signal increase of 10% is generated. In a perfect world, this increase in speed
command should bring the motor speed back to normal.
Integral Control (I)
Default Setting: 1.00
Range: 0.00 to 100.0 sec (0.00 disable)
Using only the Proportional Control, the corrective action may not increase fast
enough or the setpoint may never be reached because of system losses. The
Integral Control is used to generate additional corrective action.
When tuning, begin with a large Integral value and reduce the value until the
system goes unstable (erratic). When instability is reached, increase the Integral
value slightly until the system becomes stable and the desired setpoint value is
reached.
Derivative Control (D)
Default Setting: 0.00
Range: 0.00 to 1.00 sec
If the control output is too sluggish after the Proportional Control (P) and Integral
Control (I) values are set, Derivative Control (D) may be required. Begin with a
high Derivative value and reduce the value to the point of system instability. Then
increase the Derivative value until the control output regains stability. Stability
can be tested by moving between two wide-spread setpoint values.
P7.22
P7.21
P7.20
Chapter 4: AC Drive Parameters
DURA
PULSE AC Drive User Manual 1st Ed. Rev. D 05/2013