dolycon CT100 Series - Page 131

CT100 inverter Detailed instructions of function parameters
127
F09.04
PID output upper limit
(reserved)
Setting range: -100.0 ～
100.0%
Default value:
100.0%
F09.05
PID output lower limit
(reserved)
Setting range: -100.0 ～
100.0%
Default value:
0.0
F09.04 PID output setting frequency or voltage upper limit.
F09.05 PID output setting frequency or voltage lower limit.
F09.06
Proportional gain P
Setting range: 0.00 ～
100.00
Default value:
0.10
F09.07
Integral time I
Setting range: 0.01 ～
10.00s
Default value:
0.10s
F09.08
Differential time D
Setting range: 0.00 ～
10.00s
Default value:
0.00s
Proportional gain (P): When the feedback and preset have offset, the adjustment
is proportional to the offset. The offset is constant, so is the adjustment.
Proportional gain can respond to feedback changes but only proportional gain
cannot achieve floating control. The larger the proportional gain, the higher the
adjusting speed. Too large P may cause oscillation. Set the integral time quite
long and differential time to zero, make the system run through proportional gain,
change the preset value and check the offset of the feedback and the preset. If
the offset is in the direction of the preset variation, continue to increase
proportional gain; otherwise, decrease it. Repeat the operation till the offset is
much smaller.
Integral time (I): When the feedback and preset have offset, the adjustment is
accumulated continuously. If the offset remains, increase the adjustment till no
offset. Integral controller can effectively eliminate offset, the smaller the integral
time, the stronger the effect. However, too strong integral effect may cause
repeated over adjustment and even oscillation. Adjust the integral time from large
to small gradually and check the effect till the speed of the system becomes
stable.
Differential time (D): When the feedback and preset have offset, the adjustment
is proportional to the offset. The adjustment is only related to the direction and
size of offset variation and it has nothing to do with offset. When the feedback
signal changes, differential time is used to perform adjustment based on
variations and thus suppress feedback signal change, the larger the differential
time, the stronger the effect. Please use differential controller with cautions,
because the adjustment can easily enlarge system interference, especially
interference with frequent change.
F09.09
Sampling cycle T
Setting range: 0.00 ～
Default value: