Master/Slave Function For Active Infeed - Siemens SINAMICS S120 Function Manual

Function modules

9.9 Master/slave function for Active Infeed

9.9 Master/slave function for Active Infeed
Overview
The "Master/Slave" function module allows drives to be operated with a redundant infeed unit.
Redundancy can only be implemented in the components specified below, such as Line
Modules, Motor Modules and Control Units.
This function requires each infeed unit to be controlled 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 infeed units are appropriately configured,
operation can continue even if an infeed unit 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 unit can be decoupled from the DC link by means of a DC breaker.
Applications
The function can be used 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 unit fails
(full redundancy).
● Expansion of output range for plants with infeed units of different dimensions.
● Infeed units from line supplies/transformers with phase displacement and/or voltage
difference to a common DC link.
Function description
The "Master/Slave" function module is not implemented in the higher-level controller. The
"Master/Slave" function module can be found in the firmware of the Control Units and infeed
units. The status of the "Master/Slave" function module is indicated by the signal r0108.19 = 1.
In the function module, the V
implemented using multiplexers of the Active Line Module control.
All infeed units must be parameterized in such a way that they are fully functional as both a
master and slave. The infeed units can be switched between master and slave role during
operation. Switchover is handled by a higher-level control according to the setting in parameter
p3513. A master is configured to operate with V
the slaves operate only with current control (p3513 = 1). The setpoint input of the active current
I
active(set)
Control Units.
506
voltage control (parameter p3513 = 0) with current control. The slaves
dc
dc
is transferred from the master to the slaves via the communication links between the
control band and the current setpoint value specification are
control (p3513 = 0) and current control, while
dc
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions