COVER serii NHS – User Manual
COMEX S.A.
19
3. UPS operation modes
This chapter describes the basic modes of the PSU's operation, battery management and protection.
警告
危 险
Warning: There are dangerous voltages - mains and batteries inside the power supply
Inside the UPS, there are no components requiring user service. Only the authorized service of the
manufacturer has the option of opening the UPS enclosure.
3.1. Introduction
The UPS guarantees the highest reliability of power for critical devices. The voltage parameters
generated by the power supply are stable and free of fluctuations in both voltage and frequency, and
completely independent of the voltage parameters in the professional network.
Obtaining high quality parameters guarantees high frequency double processing with pulse width
modulation (PWM), all controlled using digital signal processing (DSP) which ensures high reliability and
convenience of use.
3.2. Principle of operation
As shown in the figure below, the supply voltage from the professional network powers the UPS rectifier.
The rectifier converts alternating voltage (AC) to DC voltage. The DC voltage supplies the inverter
system, which converts the DC voltage into a stable alternating voltage (AC), which is completely
independent of the input voltage. In the absence of mains voltage, the inverter system is supplied from
the voltage accumulated in the batteries. In the case of maintenance work, or in the event of
overloading, overheating or other events on the UPS, a back-up power supply line is used - Bypass.
Figure 3-1 Block diagram of the power supply
3.2.1. Bypass module
The Bypass system is an electronic uninterruptible switch that supplies voltage to the receivers from the
inverter output or via Bypass. During normal operation, the receivers are supplied directly from the
inverter output, but in the case of events such as overload, overheating or damage to the inverter, the
loads are automatically switched to the power supply from the Bypass path.
To ensure an uninterrupted changeover between inverter operation and Bypass operation, the inverter
output must be synchronized with the Bypass line voltage at all times. Synchronization is ensured by the
