Speed-Dependent Current Setpoint Filter; Machine Data; Description - Siemens SINUMERIK 840C Installation Instructions Manual

08.96
12.33.4

Speed-dependent current setpoint filter

A speed-dependent current setpoint filter (torque setpoint smoothing) allows the user to reduce
the speed ripple at higher speeds (MSD + FDD).
12.33.4.1

Machine data

MD 1245: Threshold speed-dependent torque setpoint smoothing
MD 1246: Hysteresis speed-dependent torque setpoint smoothing
12.33.4.2

Description

If the threshold value is set to 0, then the filter remains active as a low-pass over the entire
speed range. When other values are set, the settings in
MD 1245: Threshold speed-dependent torque setpoint smoothing and
MD 1246: Hysteresis speed-dependent torque setpoint smoothing
are used to calculate two switchover speeds:
n = n + n
upper threshold hysteresis
n = n – n
lower threshold
The low-pass function is activated then the absolute actual speed value exceeds the value
n (In I n ). Vice versa, the low-pass function is deactivated when the absolute
upper act upper
actual speed value drops below n
If the hysteresis is set to zero, then the two switchover speeds are identical.
Note
The speed threshold is effective only when filter 2 is configured as a low pass. This machine
data has no effect on the closed-loop control.
Filter type
(2nd current setpoint filter)
Speed n
n
upper
n
threshold
n
lower
Fig. 12-8 Threshold of speed-dependent torque setpoint smoothing
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
= MD 1245 + MD 1246
= MD 1245 – MD 1246
hysteresis
(In I < n
lower act lower
Bypass Low pass
6FC5197- AA50
12 Functional Descriptions
12.33.4 Speed-dependent current setpoint filter
).
Bypass
MD 1246
MD 1245
MD 1246
12–347