Chapter 4 Parameters
4-156
It can be used to set the proportional gain to decide the responds speed. The larger value is
set in Pr.10.02, the faster response it will get. The smaller value is set in Pr.10.02, the slower
response it will get.
If the other two gains (I and D) are set to zero, proportional control is the only one effective.
Related parameters: Pr.10.03(Integral Time (I)) and Pr.10.04(Differential Control (D))
10.03
Integral Time ( I )
Unit: second
Settings
0.00 to 100.0 sec
Factory Setting: 1.00
0.00
Disable
The integral controller is used to eliminate the fault during stable system. The integral control
doesn’t stop working until fault is 0. The integral is acted by the integral time. The smaller
integral time is set, the stronger integral action will be. It is helpful to reduce overshoot and
oscillation to make a stable system. At this moment, the decreasing fault will be slow. The
integral control is often used with other two controls to become PI controller or PID controller.
This parameter is used to set the integral time of I controller. When the integral time is long, it
will have small gain of I controller, the slower response and bad external control. When the
integral time is short, it will have large gain of I controller, the faster response and rapid
external control.
When the integral time is too small, it may cause system oscillation.
When it is set to 0.0, the integral function is disabled.
Related
parameter:
Pr.10.05(Upper
Bound for Integral Control)
10.04
Differential Control (D)
Unit: second
Settings
0.00 to 1.00 sec
Factory Setting: 0.00
The differential controller is used to show the change of system fault and it is helpful to preview
the change of fault. So the differential controller can be used to eliminate the fault to improve
system state. With the suitable differential time, it can reduce overshoot and shorten
adjustment time. However, the differential operation will increase the noise interference.
Please note that too large differential will cause big noise interference. Besides, the differential
shows the change and the output of the differential will be 0 when there is no change.
Therefore, the differential control can’t be used independently. It needs to be used with other
two controllers to make a PD controller or PID controller.
This parameter can be used to set the gain of D controller to decide the response of fault
change. The suitable differential time can reduce the overshoot of P and I controller to
decrease the oscillation and have a stable system. But too long differential time may cause
system oscillation.
The differential controller acts for the change of fault and can’t reduce the interference. It is not
recommended to use this function in the serious interference.
10.05
Upper Bound for Integral Control
Unit: %
Settings
0 to 100 %
Factory Setting: 100
This parameter defines an upper bound or limit for the integral gain (I) and therefore limits the
Master Frequency. The formula is: Integral upper bound = Maximum Output Frequency
(Pr.01.00) x (Pr.10.05).
Too large integral value will make the slow response due to sudden load change. In this way, it
may cause motor stall or machine damage.
Related parameter: Pr.01.00(Maximum Output Frequency (Fmax))
