Siemens SINAMICS G130 Engineering Manual page 204

Fundamental Principles and System Description
Engineering Information
Comments on a)
With firmware versions of 4.5 and lower, it is absolutely essential for the separate winding systems to be in-phase, as
the pulse patterns of the parallel-connected Motor Modules are synchronized by the Control Unit and therefore
absolutely identical. With firmware version 4.6 and higher, winding systems which are out of phase by 30° are
basically possible if certain boundary conditions are fulfilled. Further information is available on request.
a1) The variant with completely electrically isolated winding systems in which a separate Motor Module in the
parallel connection is assigned to each winding system should be selected where possible because
·
no decoupling measures need to be implemented at the converter output,
·
no circulating currents can develop between the systems,
·
the best possible current balance is achieved.
Parameter p7003 must be set to "1" during commissioning for this variant (multiple electrically isolated
winding systems).
a2) The variant with completely electrically isolated winding systems in which a separate Motor Module in the
parallel connection is not assigned to each winding system is also possible – as illustrated in the example below
by a motor with three winding systems and a converter with two Motor Modules. By comparison with the variant
described under a1) – and similar to the variant described under b) – this variant has a number of
disadvantages:
·
Decoupling measures are required (minimum cable lengths or motor reactors).
·
Circulating currents between the parallel-connected Motor Modules cannot be eliminated completely.
·
The quality of current balance between the Motor Modules in the parallel connection is slightly poorer.
Parameter p7003 must be set to "0" during commissioning for this variant (single winding system).
Motor with three electrically isolated winding systems and converter with two Motor Modules
Note:
It is also possible to supply a motor with completely isolated winding systems by a single converter or a single Motor
Module, as illustrated by the example below:
Motor with two electrically isolated winding systems and converter with one Motor Module
SINAMICS Engineering Manual – November 2015
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Ó Siemens AG