Siemens Simovert Masterdrives Compendium page 262

09.2008
Friction
characteristic faults
and alarms
7.3.2 Torque constant adaptation for synchronous motors
(function diagram 393)
Siemens AG 6SE7087-6QX70 (Version AK)
SIMOVERT MASTERDRIVES
F099:
Measuring has been terminated, the reason is given by the fault
variable (P949).
Meaning of the fault variable:
Bit Val.
0 1 Positive direction of rotation not possible
1 2 Negative direction of rotation not possible
2 4 Releases absent
3 8 Assignment not allowed
4 16 Termination through cancellation of the record command
5 32 Dataset switchover
6 64 Time exceeded (switch ON or switch ON again)
7 128 Measuring fault: Measuring point not reached or measured
value not plausible.
A72:
Waiting for ON command, max. 30 s.
A73:
Waiting for ON command when measuring interrupted, max. 5 min.
A74:
Measuring of all characteristic points in the positive and negative
directions of rotation is not possible.
The function "torque constant adaptation for synchronous motors"
serves to improve the absolute torque accuracy for control of
synchronous motors. Variations in the magnetization of the permanent
magnets arise from manufacturing tolerances and temperature
fluctuations.
This "kT estimator" function adapts the torque constant kT [Nm/A] in the
control to the instantaneous magnetization.
It makes sense to use the kT estimator only in combination with the
friction characteristic because the kT estimator corrects only the
internal torque of the machine. The friction losses must be
compensated by an additional torque derived from the friction
characteristic.
Compendium Motion Control
Meaning
Functions
7-53