User manual

Chapter 6 Control Modes of Operation ASDA-A User Manual
4th Edition 2005/11/30, HE03 © DELTA ELECTRONICS, INC. ALL RIGHTS RESERVED
6-28
Low-pass filter
Please use parameter P2-25. The figure below shows the resonant open loop gain.
Gain
Frequency
When the low-pass filter (parameter P2-25) is adjusted from 0 to high value, the value of BW will become
smaller (see the figure below). The resonant condition is improved and the frequency response and phase
margin also decrease.
0dB
BW
Gain
Frequency
Notch Filter
If the resonant frequency can be recognized, then users can directly use notch filter (parameter P2-23,
P2-24) to eliminate the resonance. However, the range of frequency setting is only from 50 to 1000Hz and its
resonant attenuation is only 0~32 dB. If the resonant frequency is out side of this range, we recommend
users to use low-pass filter to improve resonant condition.