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3. Functional Block
As a true online UPS, the product applies a double conversion topology, comprising functional blocks as
shown in Figure 3.1
Figure 3.1 Function block Diagram
The CNTL block controls the action of the UPS system. It also provides the communication interface for
receiving and executing command from users via the panel or other communication protocol. When the
UPS becomes abnormal, in most case, the CNTL can provide basic information indicating the status of
the UPS.
The Rectifier and PFC blocks are the input stage of the UPS. The blocks convert AC input power into
two stable DC power stored in the BUS capacitor. In the meantime, PFC (Power Factor Correction) will
be executed and allows input current tracking the input voltage waveform. Therefore, the input power
factor will be corrected to 1 to achieve maximum efficiency and produce lowest power pollution to the
utility.
The PFC block in battery mode, also called Booster, is used to convert the low voltage DC power to
higher voltage with stable DC power, stored in the BUS capacitor.
The Inverter block is the output stage of the UPS and used to convert DC power from the BUS capacitor
to sine waveform output power.
When the utility is within the acceptable range, the UPS will provide power directly from the utility input
and the Rectifier and PFC will be executed at the same time. When the utility is outside of the acceptable
range, no matter it
’s because of input voltage or input frequency, the UPS will shut down the Rectifier
and PFC functions and turn on the Battery Booster. In case of sudden interruption from input utility, the
controller can detect the interruption in very short time. During the short interval of detecting the
interruption, the output power will be provided by the power stored in the BUS capacitor. In this way,
there is no any interruption on output power.
The charger charges the battery when the UPS system is in online model. You can set the current from
1A to 4A by changing the jumper. And you also can choose a different voltage corresponding to different
battery pieces by changing the jumper on the CNTL board and the charger board.
The Input EMI section provides EMI filter function. The input EMI filters can prevent the UPS from being
interference by external electronic/magnetic noise which is generated by other electronic system and