Hitachi E-Compact Medium Power Series Operation Manual page 16

Benefits:
- These types of UPS bring great protection and insulation to the transmitter due to its mode
of operation and design.
- The double conversion occurs because the AC network convert to DC and the DC voltage
convert back to AC, which eliminates any disturbance in the AC mains when converted to
DC, thus protecting the transmitter.
It is important to note that UPSs do not necessarily need to have a battery bank, thus
minimizing the cost of the final product. This solution is much better than a conventional
stabilizer due to double conversion as already explained.
- The correction of the power factor (PFC) in the no break is necessary to reduce the
cost of the electric energy, because it reduces the reactive power (VAr), reducing the
total power (VA).
It is important to emphasize that it is not efficient to have a transmitter with power factor
correction (PFC) powered by a no-break without PFC, because all the advantage
achieved by the transmitter is lost in the UPS, not resulting in energy savings. When
this type of connection made, you actually have an excellent load (resistive behavior)
for the no-break, but your power grid will see the entrance of the no break (without PFC,
high consumption).
When we have a power factor correction (PFC) UPS, it will present an excellent
behavior (low reactive power, low power consumption) to the network even if it is
connected to a PFC-free transmitter, that is, it will correct the power factor of the entire
system .
Nobreak capatibity.
Nobreak Power
= PTX *
P :
TX Potência Real [ W]
cos Φ :
Power Factor Correciton
η :
(nobreak) Nobreak efficiency
No break Example with Isolating Transformer
(cos Φ * η )
(nobreak)
E-Compact Medium Power
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