Siemens SINAMICS S120 Function Manual page 104

Servo control
5.7 Current setpoint filter
Additional examples
The following examples demonstrate the features of the parameterizable current setpoint
filters.
Low-pass 2nd order (PT2 filter)
The following figure shows the transfer function for low-pass 2nd order.
f = Denominator natural fre‐
N
quency
D
N
Table 5-2 Example: PT2 filter
Filter parameters
Characteristic frequency
f = 500 Hz
N
Damping D = 0.7 dB
N
Band-stop filter with infinite notch depth
Table 5-3 Example: Band-stop filter with infinite notch depth
Filter parameters
Blocking frequency f =
Sp
500 Hz
Bandwidth (-3 dB) f =
BB
500 Hz
Notch depth K = -∞ dB
Reduction Abs = 0 dB
Simplified conversion to parameters for general order filters:
● Infinite notch depth at the blocking frequency
● Numerator natural frequency f
● Numerator damping D
102
= Denominator damping
Amplitude log frequency curve
Amplitude log frequency curve
Z
= f
Z Sp
= 0
Phase frequency curve
Phase frequency curve
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions