Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 53)

Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011 53
Detailed Drive Operation Chapter 1
Figure 12 - Lead Filter Added to System
Figure 12 above shows the results of adding the lead-lag. The system had a
response of 5 radians/second. By adding the lead-lag filter the system response
was increased to 50 radians/second.
There is lead-lag filter for the position loops speed reference. The parameters are
Kn=Parameter 25 [STrim2 Filt Gain], Wn=Parameter 26 [SpdTrim2 Filt BW].
A typical use would be to set the lead function (Wld) to the velocity bandwidth
(parameter 90 [Spd Reg BW]) and the lag (Wlg) function to approximately five
times (5x) the lead term.
Notch Filter
A Notch Filter is used to remove a specific frequency. On analog inputs and
outputs, a notch filter could be used to eliminate any 60 Hz noise received from
adjacent 120V digital input and output wires.
The PowerFlex 700S has a notch filter that is used to eliminate any resonant
signal created by mechanical gear train. The mechanical gear train consists of two
masses (the motor and the load) and spring (mechanical coupling between the
two loads). This is shown in
Figure 13 below.
Figure 13 - Mechanical Gear Train
Kspring
BL Bm
Jm Jload