Ladis G31 Series, Service Manual

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7
3. Functional Block
As a true online UPS, the product applies a double conversion topology, comprising functional blocks as
shown in Figure 3.1
I/P EMI Rectifier PFC Inverter OP EMI
Charger
BPS STS
SPS Battery CNTL
INV STS
Bypass
Maintain Bypass
IP Breaker
Battery SCR and Relay
INV Relay
Maintain Switch
P1 Relay
Output Terminal
P1 Output Terminal
Input
Output Receptacle
COMM
a. Function block Diagram for 10K~20K
I/P EMI Rectifier PFC Inverter OP EMI
Charger
BPS STS
SPS Battery CNTL
INV STS
Bypass
Maintain Bypass
IP Breaker
Battery SCR and Relay
INV Relay
Maintain Switch
Output Terminal
Input
COMM
b. Function block Diagram for 30K
Figure 3.1 Function block Diagram
The CNTL block controls the action of the UPS system. It detects the voltage and current to control PFC
and inverter, also it supplies the protection for the UPS, When the UPS becomes abnormal, in most case,
the CNTL can provide basic information indicating the status of the UPS.
The COMM block provides the communication interface for receiving and executing command from users
via the panel or other communication protocol, also provides the LCD display task.
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 utility is normal. The charger converts AC input power to DC