2 Chapter 2 System Description
Chapter 2 System Description
The operating principle of the UPS is shown in Figure 2-1.
Rectifier/PFC
DC-to-DC
Converter
Inverter
Battery
charger
Battery
Input
Output
TVSS &
EMI/RFI
Filters
L1
N
L1
G
Dynamic Bypass
N
G
F
igure 2-1 Operating principle diagram
2.1 Transient Voltage Surge Suppression (TVSS) and EMI/RFI Filters
These UPS components provide surge protection and filter both electromagnetic interference (EMI) and radio
frequency interference (RFI). They minimize any surges or interference present in the utility line and keep the
sensitive equipment protected.
2.2 Rectifier/Power Factor Correction (PFC) Circuit
In normal operation, the rectifier/power factor correction (PFC) circuit converts utility AC power to regulated DC power
for use by the inverter while ensuring that the waveshape of the input current used by the UPS is near ideal.
Extracting this sinewave input current achieves two objectives:
The utility power is used as efficiently as possible by the UPS.
The amount of distortion reflected on the utility is reduced.
This results in cleaner power being available to other devices in the building not being protected by the Liebert
®
GXT4™.
2.3 Inverter
In normal operation, the inverter utilizes the DC output of the power factor correction circuit and inverts it into precise,
regulated sinewave AC power. Upon a utility power failure, the inverter receives its required energy from the battery
through the DC-to-DC converter. In both modes of operation, the UPS inverter is on-line and continuously generating
clean, precise, regulated AC output power.
2.4 Battery Charger
The battery charger utilizes energy from the utility power and precisely regulates it to continuously float charge the
batteries. The batteries are being charged whenever the Liebert GXT4 is connected to mains power.
2.5 DC-to-DC Converter
The DC-to-DC converter utilizes energy from the battery system and raises the DC voltage to the optimum operating
voltage for the inverter. This allows the inverter to operate continuously at its optimum efficiency and voltage, thus
increasing reliability.
Liebert GXT4 UPS 5000VA ~ 10000VA (230V) User Manual
To Next Page
Loading...
