Lenze 8400 - Manual (Page 202)

5 Motor control (MCTRL)
5.8 Sensorless control for synchronous motors (SLPSM)
202
Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
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5.8.2 Types of control
Sensorless control for synchronous motors can only be executed in the "Speed control with torque
limitation" (bTorquemodeOn = FALSE) mode.
Speed control with torque limitation
A speed setpoint is selected and the drive system is operated in a speed-controlled manner. For
adapting the operational performance, the overload in the drive train can be limited:
• 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:
Identifier
DIS code | data type
Information/possible settings
nTorqueMotLimit_a
C00830/29 | INT
Torque limitation in motor mode
• Scaling: 16384 ≡ 100 % M
max
( C00057 )
• Setting range: 0 … +199.99 %
• If keypad control is performed: Parameterisable via C00728/1 .
nTorqueGenLimit_a
C00830/28 | INT
Torque limitation in generator mode
• Scaling: 16384 ≡ 100 % M
max
( C00057 )
• Setting range: -199.99 ... 0 %
• If keypad control is performed: Parameterisable via C00728/2 .

Stop!
Torque limitation is only active in the closed-loop controlled operation (|n
Setpoint
| >
n
C00996
)!
• It must be prevented that the actual speed value is braked into the non-observable
area due to the torque limitation!

Note!
To avoid instabilities during operation, the torque limit values are internally processed
as absolute values.