Use Notch Filter To Suppress Resonance; Use Low-Pass Filter To Suppress Resonance - Delta ASD-B2-0121-B User Manual

Chapter 6 Control Modes of Operation

Use Notch Filter to suppress resonance

Resonance
Gain
Resonance
Frequency
.

Use Low-pass Filter to suppress resonance

Resonance
Gain
Resonance
Frequency
When the low-pass filter (parameter P2-25) is adjusted from 0 to high value, the value of
Low-pass frequency will become smaller (see the figure on page 6-26). The resonant
condition is improved but the frequency response and phase margin will also decrease
and the system may become unstable. Therefore, if the users know the resonance
frequency, the users can eliminate the resonance conditions directly by using notch filter
(parameter P2-23, P2-24). Usually, if the resonant frequency can be recognized, we
recommend the users can directly use notch filter (parameter P2-23, P2-24) to eliminate
the resonance. However, if the resonant frequency will drift or drift out of the notch filter
range, we recommend the users not to use notch filter and use low-pass filter to improve
resonant conditions.
6-30
Point Gain
0db
Low-pass
Attenuation
Frequency
Rate P2-24
Frequency
Gain
Point
Attenuation
Rate -3db
0db
Low-pass
Frequency
Frequency
Gain
Notch Filter
Resonance Frequency
Frequency
P2-23
.
Low-pass Filter
Gain
Cut-off Frequency
of Low-pass Filter
= 10000 / P2-25 Hz -
Frequency
Resonance
conditions
is suppressed
Low-pass
Frequency
Frequency
Resonance
Frequency .
Resonance
conditions
is suppressed
Low-pass
Frequency
Frequency
Resonance
.
Frequency
Revision June 2010