Lenze 8400 motec - Manual (Page 124)

5 Motor control (MCTRL)
5.8 Sensorless vector control (SLVC)
124 Lenze · 8400 motec · Reference manual · DMS 4.1 EN · 08/2013 · TD05
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5.8.2 Speed control with torque limitation
A speed setpoint is selected and the drive system is operated in a speed-controlled manner.
The operational performance can be adapted in the following ways:
• Overload limitation in the drive train
• The torque is limited via the torque setpoint.
• The torque setpoint is identical to the value at the output of the speed controller,
nOutputSpeedCtrl.
• To avoid overload in the drive train, the torque in motor mode can be limited via the
nTorqueMotLimit_a process input signal, and the torque in generator mode can be limited via
the nTorqueGenLimit_a process input signal:
• Motor current limitation
• A cross current setpoint is calculated from the torque setpoint which is limited depending on
the magnetising current, the max. current in motor mode ( C00022 ), and the max. current in
generator mode ( C00023 ).
• Here, the total current injected into the motor does not exceed the max. currents in motor
and generator mode.
• Slip compensation ( 154)
• Using a slip model, the slip of the machine is reconstructed.
• The slip compensation (
C00021 ) acts as the influencing parameter.
Identifier
DIS code | data type
Information/possible settings
nTorqueMotLimit_a
C00830/4 | INT
Torque limitation in motor mode
• Scaling: 16384 ≡ 100 % M
max
( C00057 )
• Setting range: 0 … +199.99 %
nTorqueGenLimit_a
C00830/5 | INT
Torque limitation in generator mode
• Scaling: 16384 ≡ 100 % M
max
( C00057 )
• Setting range: -199.99 ... 0 %

Note!
To avoid instabilities during operation, the torque limit values are internally processed
as absolute values.