WEG UPS 10 kVA Serie Manual Del Usuario página 13

General Information
2.5 PRINCIPLE OF OPERATION
The Enterprise devices are double-conversion on-line UPSs with automatic bypass, in
compliance with the NBR15014 standard. This UPS makes the double conversion of the input
voltage, continuously and without interruption.
The absence of direct connection between the device input and output eliminates the possibility
of transferring the mains disturbances to the load. The double-conversion technique provides
the feeding of the critical load with controlled voltage and frequency - ideal for operation in
critical power applications.
When the input voltage exceeds the allowable range or is not present, the load is powered by
the energy stored in the batteries.
The system comes with automatic Bypass. In case of an UPS failure or system overload, the
load is directly connected to the mains through an alternate branch, allowing the operation to
continue without interrupting the power supply to the critical loads.
2.5.1 UPS Block Diagram
R, S, T, N
Reserve
R, S, T, N
Mains
2.5.2 Input Stage, Power Module and Output Stage
The mains voltage is connected via input switch DJE. Once closed, the power is available to
the equipment power module.
The rectifier stage (responsible for the first stage of power conversion - AC/DC) controls the
system DC voltage, in addition to draining a current from the mains with extremely low harmonic
distortion through the PFC (Power Factor Correction) system. This system is controlled by the
main control module, and it also controls the battery charging voltage and current.
The DC voltage from the rectifier feeds the inverter module (responsible for the second stage
of power conversion - DC/AC). The AC voltage produced by the inverter supplies the current
according to the needs of the load, with fully controlled amplitude and frequency.
The last module that composes this UPS is the automatic bypass system. It transfers the
conditioned energy from the inverter module to the critical load during normal operating
conditions. In case of a UPS failure or overload, the automatic bypass system transfers the load
power supply, without interruption, to the alternate line.
7 | Enterprise
Manual bypass
DJBP
DJER
PFC
DJE
Pos.
Neg. Neutral
FBAT
Battery bank
Figure 2.1: UPS one-line diagram
Static
switch
INV.
DJS
R, S, T, N
Load