Lenze E94A - Manual (Page 643)

Lenze · 9400 function library · Reference manual · DMS 6.7 EN · 08/2014 · TD05
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5 Function blocks
5.207 L_WndFrictionCompensation - friction compensation
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Smoothing the actual value signals
If incremental encoders are used, it may be required to filter the actual speed value signal.
• The time constant for the filter can be set in C04848; in the majority of cases the setting "10 ms"
is sufficient.
• For smoothing the friction characteristic, it can also be helpful to filter the actual torque value
signal; the time constant for this filter can be set in C04849.
5.207.4 Activating the friction compensation
The friction compensation is active if the input bStartIdent is set to FALSE, and the input
bEnableFrictionCurve is set to TRUE.
• The current speed is preselected via the input dnSpeedSetpoint_n.
• If the actual speed value exceeds 100 %, the characteristic is extrapolated linearly.
Use of a linear characteristic
If the input dwSelectCurve is = 0 or unassigned, a linear characteristic is used for the friction com-
pensation.
• The linear characteristic is specified via parameters C04854 and C04855:
• C04854 = initial friction torque at speed "0"
• C04855 = friction torque at maximum speed (C00011)
• The characteristic is limited internally to 0 ... 200 %.
Use of a previously automatically identified friction characteristic
If the input dwSelectCurve = 1 ... 4, the friction characteristic saved on the corresponding memory lo-
cation is used instead of the linear characteristic.
 Identifying the friction characteristic automatically ( 641)
Temperature compensation
Via the input dnFrictionAdapt_n a gain for the characteristic on a percentage basis is specified, for
instance in order to compensate changes in the friction torque due to temperature changes.
Smoothing the speed reference value
For smoothing the speed reference value dnSpeedSetpoint_n, a filter time constant can be set in
C04856.
Display of the precontrol signal
The precontrol signal generated is provided at output dnFrictionTorque_n. By setting the input
bNegOutput to TRUE, you can output this signal in an inverted manner (change of direction of rota-
tion).