ABB HiPerGuard MV UPS User Manual page 28

28 H I P E R G U A R D M V U P S U S E R M A N U A L
3.2.7.3.3 Demand to absorb power into the battery
If the DRC requests the MV UPS to absorb power into the battery, the system will charge the battery while ensur-
ing that the output voltage stays at its nominal level. The DRC must supervise and manage the SOC of the battery.
Power can only be absorbed when charging capacity in the battery is available.
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Figure 3.15: MV UPS
power flow – Demand
to absorb power
into the battery.
3.2.7.4 Demand Response and parallel units
When MV UPS units are connected in hard-parallel to make a single system, as each unit has its separate battery,
each unit requires a Demand Response interface.
It is recommended that the Demand Response control system shall separately monitor the SOC of each unit and
adjust its respective references accordingly.
3.2.8 Auxiliary power supply
The auxiliary power supply of the MV UPS during PCM and IM modes of operation is generated internally. However,
an external auxiliary power supply must be available during the commissioning and servicing for starting of the
HiPerGuard MV UPS.
This is required for powering the main controller, precharging the DC bus, and controlling the MV switchgear.
For specifications on the auxiliary power supply requirements, please refer to the Installation Manual.
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Figure 3.16: HiPerGuard
MV UPS Auxiliary
Power Supply.