Parallel Connection Of Motor Modules - Siemens SINAMICS S120 Function Manual

Function modules
8.10 Parallel connection of power units
The following rules must be observed when connecting Active Line Modules in parallel:
● Up to four identical Active Line Modules can be connected in parallel.
● Active Line Modules can only be connected and operated in parallel in the vector control
mode.
● A common Control Unit must always be used to implement the parallel connection.
● Special Line Connection Modules are available for connecting the modules in parallel.
● With multiple infeeds, power must be supplied to the systems from a common infeed
point (i.e. the modules cannot be operated on different line supplies).
● A derating factor of 5% must be taken into consideration, regardless of the number of
modules connected in parallel.
The following measures help to ensure balanced currents in parallel connections of Active
Line Modules:
● Reactors in the Clean Power Filters of the Active Interface Modules.
● Use of symmetrical power cabling between the transformer and the parallel-connected
Active Interface Modules / Active Line Modules (cables of identical type with the same
cross-section and length).
● The current reduction from the rated value for individual Active Interface Modules / Active
Line Modules in a parallel connection is 5%.
6-pulse, redundant parallel connection of Active Line Modules with multiple Control Units
For a description of parallel connections of multiple Active Line Modules under the control of
separate Control Units, please refer to section "Master/slave function for Active Infeed
(Page 549)".
12-pulse parallel connection of Active Line Modules
The 12-pulse parallel connection can operate in master-slave mode (section "Master/slave
function for Active Infeed (Page 549)").
Modules with different ratings can be included in the connection (as in the case of 6-pulse
master-slave operation).
8.10.1.4

Parallel connection of Motor Modules

Up to four Motor Modules operating in parallel can supply a single motor in vector control.
The motor can have electrically isolated winding systems or a common winding system. The
type of winding system defines the following requirements:
● The required decoupling measures at the outputs of the Motor Modules connected in
parallel
● The possible modulation systems to generate pulse patterns
In conjunction with the type of infeed, the modulation systems define the maximum
attainable output voltage or the maximum attainable motor voltage.
568
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions