INVT GD350-004G/5R5P-45-AS, Руководство по эксплуатации

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Goodrive350 IP55 High-ingress Protection Series VFD Basic Operation Instructions
-101-
+
-
Reference-
feedback<P09.08
？
P09.10
(lower limit value of PID
output)
P09.09
（
upper limit value of PID
output
）
0
1
P09.03
(PID output characteristics)
PID output
P17.00
P17.23
P09.08 (Limit of PID control deviation)
P09.02
(PID feedback source)
P09.00
(PID reference source)
P17.24
PID feedback
value
PID reference value
Set frequency
0
1
2
3
4
5
6
7
8
9
Keypad
AI1
PROFIBUS/CANopen/DeviceNet
Modbus/Modbus TCP
Multi-step speed
HDIA
AI3
AI2
Ethernet
HDIB
0
1
2
3
4
5
6
7
AI1
PROFIBUS/CANopen/DeviceNet
Modbus/Modbus TCP
HDIA
AI3
AI2
Ethernet
Y
N
PID stops
adjustment
PID digital setting
Keep current frequency
Terminal function 25
PID control pause
Valid
Invalid
Kp P09.04 (proportional gain)
Ti P09.05 (integral time)
Td P09.06 (differential time)
P09.01
EtherCAT/PROFINET/EtherNet IP
Programmable card
10
11
HDIB
EtherCAT/PROFINET/EtherNet IP
Programmable card
8
9
Introduction to the working principles and control methods for PID control
Proportional control (Kp):
When the feedback is different from the reference, the output will be proportional to the
difference. If such a difference is constant, the regulating variable will also be constant.
Proportional control can respond to feedback changes rapidly, however, it cannot eliminate the
difference by itself. A larger the proportional gain indicates a faster regulating speed, but a too
large gain will result in oscillation. To solve this problem, set the integral time to a large value
and the differential time to 0, run the system only with proportional control, and then change
the reference to observe the difference (that is, static difference) between the feedback signal
and reference. If the static difference occurs in the direction of reference change (such as
reference increase, where the feedback is always less than the reference after system
stabilizes), continue increasing the proportional gain; otherwise, decrease the proportional
gain. Repeat this process until the static difference becomes small.
Integral time (Ti):
When feedback deviates from reference, the output regulating variable accumulates
continuously, if the deviation persists, the regulating variable will increase continuously until
deviation disappears. Integral regulator can be used to eliminate static difference; however, too
large regulation may lead to repetitive overshoot, which will cause system instability and
oscillation. The feature of oscillation caused by strong integral effect is that the feedback signal
fluctuates up and down based on the reference variable, and fluctuation range increases
gradually until oscillation occurred. Integral time parameter is generally regulated gradually
from large to small until the stabilized system speed fulfills the requirement.
Derivative time (Td):
When the deviation between feedback and reference changes, output the regulating variable
which is proportional to the deviation variation rate, and this regulating variable is only related
to the direction and magnitude of the deviation variation rather than the direction and
magnitude of the deviation itself. Differential control is used to control the feedback signal
variation based on the variation trend. Differential regulator should be used with caution as it
may easily enlarge the system interferences, especially those with high variation frequency.