Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual - Manual (Page 60)

60 Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013
Chapter 1 Detail Drive Configuration and Operation
The resonant frequency is defined by the following equation:
• Jm is the motor inertia (seconds).
• Jload is the load inertia (seconds).
• Kspring is the coupling spring constant (rad2/sec).
Figure 20 shows a two mass system with a resonant frequency of 62 rad/sec. One
Hertz is equal to 2p rad/sec.
Figure 20 - Resonance
The small inset shows a better representation of resonant frequency better.
The PowerFlex 700S has a notch filter in the torque reference loop to eliminate
such noise from the system. The notch filter frequency is parameter 118 [Notch
Filt Freq]. Due to the fact that most mechanical frequencies are described in
Hertz, [Notch Filt Freq] is in Hertz as well.
Figure 21 on page 61 shows the same mechanical gear train as in Figure 20 .
[Notch Filt Freq] is set to 10.
resonance Kspring
Jm Jload +
( )
Jm Jload
Ч
--------------------------------- Ч
=