Chapter 5 Parameters
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VFD-B-P Series
5-98
Revision April 2009, SW V1.00
10 - 04
Derivative Control (D)
Unit: 0.01
Settings
0.00 to 1.00 sec
Factory Setting: 0.00
This parameter specifies derivative control (rate of change of the input) and associated gain
(D). With this parameter set to 1, the PID output is equal to differential time x (present
deviation
−
previous deviation). It increases the response speed but it may cause over-
compensation.
10 - 05
Upper Bound for Integral Control
Unit: 1
Settings
00 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)%.
This parameter can limit the Maximum Output Frequency.
10 - 06
Primary Delay Filter Time
Unit: 0.1
Settings
0.0 to 2.5 sec
Factory Setting: 0.0
To avoid amplification of measurement noise in the controller output, a derivative digital filter is
inserted. This filter helps to dampen oscillations.
The complete PID diagram is shown on the following page:
P
10-02
I
10-03
D
10-04
10-05
10-01
10-07
10-06
10-00
+
-
+
+
+
Setpoint
Input Freq.
Gain
PID
feedback
Integral
gain
limit
Output
Freq.
Limit
Digital
filter
Freq.
Command
10 - 07
PID Output Frequency Limit
Unit: 1
Settings
00 to 110 %
Factory Setting: 100
This parameter defines the percentage of output frequency limit during the PID control. The
formula is Output Frequency Limit = Maximum Output Frequency (Pr.01-00) X Pr.10-07 %.
