Scope Of Application Of Bandstops As Current Setpoint Filter - Siemens SINUMERIK 840C Installation Instructions Manual

12 Functional Descriptions
12.33.3 Current setpoint filter
12.33.3.3

Scope of application of bandstops as current setpoint filter

Bandstop filters must be dimensioned such that resonance is kept reliably low while the filter
effect on the fundamental frequency range is minimized.
Filter in the case of resonance in the fundamental frequency range
Resonance in the fundamental frequency range can normally be restricted by means of control
parameters.
Filter in the case of resonance at and above the controller stability limit
Bandstop as current setpoint filter
Bandstops generally provide improved damping with the same phase rotation.
– Suitable in cases of pronounced mechanical resonance (peaks), no distribution of
resonance phenomena.
– Blocking filters at frequencies above the controller stability limit may eliminate interference
resonance in the fundamental frequency range.
A bandstop is used when a narrow, pointed peak exceeds the 0 dB line in the amplitude
response at a fixed frequency (above the fundamental frequency range of the speed
controller). This causes a clearly audible whistling noise in the drive train.
Depending on requirements, the bandstop can be set in two configurations.
• Simple bandstop with
Blocking frequency:
Bandwidth:
• Bandstop with adjustable damping of amplitude response plus counter
bandwidth:
Note
The bandstop frequency of a current setpoint filter must be lower than the Shannon frequency
(parameterization error). The bandstop frequency for filter 1 (MD 1210), filter 2 (MD 1213),
filter 3 (MD 1216) and filter 4 (MD 1219) must be lower than the reciprocal of two current
controller clock cycles.
MD 1210, MD 1213, MD 1216, MD 1219 <
12–342
MD 1210 (filter 1), MD 1213 (filter 2), MD 1216 (filter 3),
MD 1219 (filter 4)
MD 1211, MD 1214, MD 1217, MD 1220
MD 1212, MD 1215, MD 1518, MD 1512
2 x MD 1000
© Siemens AG 1992 All Rights Reserved
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6FC5197- AA50
SINUMERIK 840C (IA)
08.96