ABB HiPerGuard MV UPS User Manual page 27

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3.2.7.3.2 Demand to inject power from the battery
If the DRC requests the UPS to inject power from the battery, the MV UPS will discharge the battery.
The HiPerGuard MV UPS system supplies power P
ence between UPS output and load power. In case of the power demanded by the load (P
available from the demand response (P
the grid power is zero.
If the demanded power (P
power into the grid.
—
The maximum available power to be injected into the grid is the MV UPS sys-
tem rating minus the load power.
The HiPerGuard MV UPS can optionally be configured to prevent grid power back-feed if a DRC Power-setpoint is
greater than the current load power. This is useful if the load reduces faster than the DRC can respond. This func-
tion is enabled via a configurable parameter on the MV UPS.
P = P
DR Load
—
Figure 3.12: MV
UPS power flow
P > P and grid back-feed is enabled
DR Load
—
Figure 3.13: MV UPS
power flow – PDR >
PLoad and grid back-
feed is enabled.
as demanded by the DRC while the grid supplies the differ-
DR
), the full load power is supplied by the HiPerGuard MV UPS. In this case,
DR
) exceeds the load power (P
DR
—
Figure 3.11: MV UPS
power flow – De-
mand to inject power
from the battery.
P < P
DR Load
), the MV UPS will support the full load but also inject
Load
—
If the demanded power
exceeds the load power
but grid back-feed is not
allowed, then the HiPer-
Guard MV UPS will limit
the P
P
Load
P > P
DR
) is the same power
Load
to be equal to the
DR
.
and grid back-feed is disabled
Load
—
Figure 3.14: MV UPS
power flow – PDR >
PLoad and grid back-
feed is disabled.