Siemens SINAMICS G150 Operating Instructions Manual page 391

Extended procedure: closed-loop controlled operation to zero speed
By superimposing high-frequency pulses on the driving fundamental voltage and evaluating
the resulting offset pulse in the machine current, it is possible to determine the continuous
rotor position up to frequency zero (standstill).
1FW4 and 1PH8 series Siemens torque motors can be started from standstill with any load
up to the rated torque or even hold the load at standstill.
The procedure is suitable for motors with internal magnets.
Note
If a sinewave filter is used, the open-loop controlled procedure should be used.
The following advantages are obtained by maintaining closed-loop controlled operation:
● No switchover required within closed-loop control (smooth switching, no discontinuities in
● Closed-loop speed and torque control without encoder (sensorless) up to and including 0
● Higher dynamic performance when compared to open-loop controlled operation.
● Encoderless operation of drive line-ups (e.g. in the paper industry, master-slave
● Active (including hanging/suspended) loads down to zero frequency.
Supplementary conditions for the use of third-party motors:
● Experience shows that the procedure is very suitable for motors with magnets within the
● The ratio of stator quadrature reactance (Lsq): Stator direct-axis reactance (Lsd) must be
● The possible operating limits of the procedure depend upon up to what current the
A prerequisite for optimum behavior is the entry of the following parameters:
● Enter the saturation characteristic: p0362 - p0369
● Enter the load characteristic: p0398, p0399
Commissioning sequence for closed-loop controlled operation to zero speed:
● Run through the commissioning with motor identification at standstill.
● Enter the parameters for the saturation characteristic and the load characteristic.
● Activate closed-loop controlled operation to zero speed via parameter p1750 bit 5.
Converter cabinet units
Operating Instructions, 03/2012, A5E03263466A
the torque).
Hz.
operation).
rotor core (IPMSM - Interior Permanent Magnet Synchronous Motors).
> 1 (recommendation: minimum > 1.5).
asymmetrical reactance ratio (Lsq:Lsd) is retained in the motor. If the procedure should
be operable up to the rated motor torque, then the reactance ratio must be retained up to
the rated motor current.
Setpoint channel and closed-loop control
7.4 Vector speed/torque control with/without encoder
389