Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 319

The drive requires the use of a PLC to provide average I
to modify the flux demand through the flux droop scaler.
Since flux is provided through induction from the stator to the rotor which is fed by both drives,
flux feedback to each drive must be precise to control the contribution of each drive. By sampling
the I
as a modifier of the flux demand.
The PLC reads the average, individual drive reactive currents to the machine, and then divides
the current requirement into equal shares, and passes the I
through a network connection to the drive. It proportions the total current by the number of
drives connected to the motor, by determining the field-producing current share for each drive.
The drives total magnetizing current must be an equal share from each connected drive. This
then equalizes the torque capability of each drive for the motor total torque so that each drive
is contributing the same amount of torque and magnetizing current. The result is equal sharing
between each drive.
The success of balancing the flux producing reactive currents between drives is more an exercise
of balancing the attenuator impedances than in any control algorithm or setting of droop
parameters.
Figure 8-24
Parameter for Flux Droop
The Flux Droop parameter (3195) can be used for scaling, or turning off this feature by setting
to zero, the default value.
Note
Use of Flux Droop results in lower flux on the machine. This can be adjusted by slightly increasing
the "Flux demand" (3150) parameter to greater than 1.0.
Spinning load must be disabled for running parallel drives on a single induction motor.
NXGPro+ Control Manual
Operating Manual, A5E50491925A
feedback of each drive, an average can be calculated to feedback as a reference to each
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Parallel Drive Control with Induction Motor
Advanced Operating Functions
8.20 Paralleling Multiple Drives
to each drive over a network. This is used
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current demand share to each drive
ds
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