HSD CPH 400 B, Assembly Instructions Manual

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3 Main parts
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HSD S.p.A. © - h0102k02a.fm091115
3.5 Shared DC Bus
In the term "shared DC Bus", "shared" is intended as the power contribution from a number of
sources connected in parallel along the DC Bus line.
The principal characteristic of all the versions of the SM141/CPH400 is that the drive is integrated
with or near to the motor, in other words with a shared AC Bus, in that each drive draws power
locally from its own power supply unit (also integrated). This characteristic has two advantages:

absence of electrical devices in the electric cabinet of the user machine;

each SM141/CPH400 can generate the continuous voltage locally by means of its own power
supplier, which is sized precisely as a function of the power of the electric motor.
The SM141D/CPH400 GREEN version also
shares the DC Bus with other motors of the
same type. In this way, all the advantages of
both systems are incorporated in a single
solution (shared AC Bus or shared DC Bus).
Thanks to the common DC Bus, each drive
contributes its own energy to the DC Bus
network, progressively increasing the
available power as the number of motors
connected to the network increases.
The effects are:
1. Energy recovery. The capacity to accumulate energy during braking is equal to the sum of the
energy stored by each drive. For example, each SM141/CPH400 device can accumulate
energy that can be re-used by it or by other devices connected to the DC Bus. If follows that
the need to dissipate energy to the integrated braking resistance only occurs in particular
cases, such as for example, in an emergency stop of all the motors at the same time.
2. The sizing of the power supply unit does not present any problems, in that each device adds
the maximum power relative to its size to the network and which is nevertheless available for
the others when it is not being used for its own purposes.
3. Ripple is, on average, reduced, in that a part of the peak energy necessary for acceleration is
taken from the other motors that have it available.
4. In the case of applications with high energy regeneration (e.g. a descending lift), it is possible
to add another accumulation, regeneration or dissipation device to the DC line in order to
reduce excessive increases in the DC Bus voltage.