Master/Slave Function For Active Infeed; Operating Principle; Basic Structure - Siemens SINAMICS S120 Function Manual

8.9

Master/slave function for Active Infeed

8.9.1

Operating principle

This function allows drives to be operated with a redundant infeed. Redundancy can only be
implemented in the components specified below, such as Line Modules, Motor Modules and
Control Units. The function can be applied for the following applications:
● Hoisting gear that is to continue functioning in emergency mode (e.g. so that the load can
still be placed down).
● Paper and steel works that require a line drive to continue operation at a reduced line
velocity.
● Oil production platforms that must continue normal production even if one infeed fails (full
redundancy).
● Expansion of output range for plants with infeeds of different dimensions.
● Infeed from line supplies/transformers with phase displacement and/or voltage difference
to a common DC link.
This function requires each infeed to be served by a separate Control Unit. It also requires
either a higher-level control system (e.g. SIMATIC S7) to transfer current setpoints using the
PROFIBUS slave-to-slave communication capability or TM31 modules which transfer current
setpoints in the form of analog signals. If the infeeds are appropriately configured, operation
can continue even if an infeed has failed. The master is selected by the controller and
operated under V
receive their setpoint directly from the master and are only operated under current control
(parameter p3513 = 1).
Electrical isolation from the line with isolating transformers is necessary to prevent equalizing
currents from flowing.
The infeed can be decoupled from the DC link by means of a DC breaker.
8.9.2

Basic structure

DRIVE-CLiQ can be used to connect an Active Line Module (ALM) to a Control Unit (CU)
and Voltage Sensing Module (VSM) to create an infeed train. A Motor Module together with
a Sensor Module Cabinet (SMC) or Sensor Module External (SME) forms a drive train. A
Control Unit controls the complete drive system.
If one of the components develops a fault, only the affected train will fail. This failure can be
signaled, e.g. via read parameter r0863.0, as a message to the higher-level controller. The
fault is evaluated in the user program of the higher-level controller, which sends
corresponding signals to the other infeeds. If a higher-level controller is not used, the fault
can be evaluated by means of DCCs in the Active Line Modules.
All the other trains remain fully functional, which means that they can continue operating
normally.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
voltage control (parameter p3513 = 0) with current control. The slaves
dc
8.9 Master/slave function for Active Infeed
Function modules
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