Vertiv Liebert EXS 80kVA UPS, Руководство пользователя

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Vertiv™ Liebert EXS 80kVA UPS User Manual
1 Overview
1.2 Design Concept
1.2.1 System Design
This section introduces the working principle of the UPS single module. The UPS adopts AC-DC-AC
converter (as shown in Figure 1-1 ). The first stage conversion (AC-DC) adopts three-phase high frequency
rectifier to convert the three-phase input voltage into stable DC bus voltage. The second stage conversion
(DC-AC) adopts three-phase high frequency inverter to convert the DC power supply into the three-phase
AC input voltage.
Figure 1-1 Block diagram for working principle of UPS single module
Input
Maintenance bypass switch
Bypass input switch
Rectifier input switch
Bypass input
Mains input
Battery charger
Output switch
Inverter switch Inverter Rectifier
Static switch
Maintenance bypass
UPS output
Battery
Output
Bypass automatic switch
1. The UPS is composed of mains input (main and bypass), rectifier/PFC, charger, inverter, bypass, battery,
and output.
2. When the mains is normal, the rectifier and inverter work together to supply the loads and charge the
battery.
3. When the mains is abnormal, the rectifier/PFC circuit boosts the battery voltage and supplies it to
the inverter. The inverter then converts it into pure sine wave AC power and supplies the AC power
to the load. If the battery voltage falls to end of discharge (EOD) voltage and the mains still has not
been recovered, the UPS will shut down (if the system uses split bypass configuration and the bypass
is normal, the system will transfer to bypass). The battery EOD voltage is preset. When the mains is
abnormal, the battery maintains the UPS operation till the battery voltage is reduced to EOD voltage
and the UPS shuts down, this time is called 'Backup Time'. The length of backup time depends on the
battery capacity and the loads.
4. After the mains returns to normal state, the UPS will automatically transfer from Battery mode to
Normal mode, and the rectifier and inverter work together to supply the loads and charge the battery.