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PSI 10000 4U Serie
3.11
Other applications
3.11.1
Parallel operation in master-slave (MS)
Multiple devices of same kind and model can be connected in parallel in order to create a system with higher total
current and hence higher power. For parallel operation in master-slave mode the units are usually connected with
their DC outputs, their Share bus and their master-slave bus, which is a digital bus that makes the system work
as one big unit regarding adjusted values, actual values and status.
The Share bus is intended to balance the units dynamically in their voltage on the DC output, i.e. in CV mode,
especially if the master unit runs a dynamic function. In order for this bus to work correctly, at least the DC minus
poles of all units have to be connected, because DC minus is the reference for the Share bus.
Principle view (without load or source):
Share bus connection
Master-slave bus
3.11.1.1
Restrictions
Compared to normal operation of a single device, master-slave operation has some
restrictions
:
•
The MS system reacts partly different in alarm situations (see below in
•
Using the Share bus makes the system react as dynamic as possible, but it’s still not as dynamic as single unit
operation
•
Connection to identical models from other series is not supported, the master would not initialize them
3.11.1.2
Wiring the DC outputs
The DC output of every unit in the parallel operation is connected with correct polarity to the next unit, using cables
or copper bars with a cross section according to the total system current and with short as possible length, so
their inductance is as low as possible. The same applies when building several blocks of devices, i. e. a block of
power supplies and a block of electronic load, to later connect then in two-quadrant operation. The blocks should
be placed as close as possible to each other.
