gefran VDI100 Series Instruction Manual page 215

Differential control: This control is the inverse from integral control and tries to guess the behavior of the error
signal by multiplying the error with the differential time. The result is added to the PID input. Differential control
slows down the PID controller response and may reduce system oscillation. Note: Most applications that PID
control (fan and pump) do not require differential control.
Refer to Figure 4.4.77 for PID control operation
PID Control Type
The inverter offers two types of PID control:
(a) PID control with differential feedback: (10-03 = x1xxb)
Make sure to adjust the PID parameters without causing system instability. Refer to Figure 4.4.78 for PID con-
trol for feedback value differential.
(b) Basic PID control: (10-03 = x0xxb)
This is the basic type of PID control. Refer to the figure 4.4.79.
PID Setup
Enable PID control by setting parameter 10-03, PID target value (10-00) and PID feedback value (10-01).
To use PID control set frequency command selection 00-05 to 4.
(1) Select PID target value (10-00):
10-00: PID target value
=1: analog AI1 given (default)
=2: analog AI2 given
=3: Pulse given
=4:10-02
=6 frequency command (00-05)
VDI100 • Instruction manual
Deviation
Control
Figure 4.4.78 PID control for feedback differential value
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Set Value
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Feedback
Figure 4.4.79 Basic PID control
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Set Value
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Feedback
Figure 4.4.77 PID Control
D
P
I
D
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P
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I
D
t
PID Control
I Control
P Control
t
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Control
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Control
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