Digitax DBE1100S, Руководство пользователя

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DigitAx User Guide
Issue code: dgxu4
A-1
A PID Loop
A.1 Setting the PID gains
1.
Apply +24V to terminal B14 and set b2 at 1 to
enable the Drive.
2.
Check the waveform on the oscilloscope. If the
waveform is similar to that shown in Figure A–1
the proportional gain is too low.
V
t
V
t
Function generator
output
Tachogenerator
output
Figure A–1 Waveform resulting from
proportional gain being too low
Increasing the value of Pr13 (proportional gain) will
achieve a waveform similar to that shown in
Figure A–2, which shows low derivative gain.
Increasing the value of
Pr14 (derivative gain) will
reduce overshoot at the expense of increased
current and possibly increased heating of the motor.
An ideal response can be achieved as shown in
Figure A–3.
V
t
V
t
Function generator
output
Tachogenerator
output
Figure A–2 Waveform resulting from
derivative gain being too low
V
t
V
t
Function generator
output
Tachogenerator
output
Figure A–3 Waveform showing ideal response
Excessive derivative gain can have the following
effects:
Excessive heating of the motor due to extra
current
Motor shaft oscillation I2t current limiting
Reduced speed of response as shown in
Figure A–4