Delta Electronics AC Servo Drive ASDA-AB User Manual page 129

Chapter 6 Control Modes of Operation|ASDA-AB Series
Low-pass filter
Please use parameter P2-25. The figure below shows the resonant open-loop gain.
Gain
When the low-pass filter (parameter P2-25) is adjusted from 0 to high value, the value of Low-pass
frequency (BW) will become smaller (see the figure below). The resonant condition is improved and the
frequency response and phase margin will also decrease.
Gain
0dB
Notch Filter
Usually, if the users know the resonance frequency, we recommend the users can eliminate the
resonance conditions directly by using notch filter (parameter P2-23, P2-24). However, the range of
frequency setting is from 50 to 1000Hz only and the range of resonant attenuation is 0~32 dB only.
Therefore, if the resonant frequency is out of this range, we recommend the users to use low-pass filter
(parameter P2-25) to improve resonant condition.
Please refer to the following figures and explanation to know how to use notch filter and low-pass filter
to improve resonant condition.
Use Notch Filter to suppress resonance
Gain
Resonance
Frequency
.
6-26
Resonance
Point
Gain
0db
Low-pass
Frequency
Frequency
BW
Notch Filter
Attenuation
Rate P2-24
Resonance Frequency
Frequency
P2-23
Frequency
Frequency
Resonance
conditions
Gain
is suppressed
Resonance
Frequency .
Revision January 2009
Low-pass
Frequency
Frequency