83
Connect two storage battery strings in parallel. A second UPS is needed as backup.
8.10.4
HVDC Power Supply
The high-voltage direct current (HVDC) system can eliminate the problems existing in
conventional AC and low-voltage DC power supplies. At present, 240 V HVDC standards
and 336 V HVDC standards are the mainstream HVDC standards used in China.
8.10.5
HVDC Power Supply Requirements
The requirements for HVDC power supply are as follows:
-
Operating range: -5
℃
- 45
℃
-
Storage and transportation range: -40
℃
- 85
℃
Relative Humidity:
-
Operating range:
≤
90% RH (40
±
2
℃
)
-
Storage and transportation range:
≤
95% RH (40
±
2
℃
)
Vibration performance: ability to withstand sinusoidal frequencies between 10 Hz
to 55 Hz and amplitude of 0.35 mm.
Battery capacity configuration: ensure continuous operation of servers at full loads
when the power supplies are unavailable. The battery backup time should be 15
minutes when a diesel generator is available as backup power source.
Determination of cell voltage and pack number: Depending on the system capacity
and backup time, the cell voltage can be selected from 2 V, 6 V or 12 V.
The insulation monitoring device acts properly if a ground fault occurs or the
insulation resistance is 28 kΩ lower than the set value. The HVDC system is
protected against overcurrent and short circuits and can be manually or
automatically restored after overcurrent or short circuits are rectified.
Over- and under-voltage protection for AC power supplies: The power supply
system can monitor the input voltage changes. When detecting that the AC input
voltage is higher or lower than the specified threshold, which may pose safety risk
on the operation of the power supply system, the system automatically shuts
down. The system automatically restores when the input voltage is normal.
The site is free from explosive materials, conductive media and hazardous gases
that erode metals and affect insulation, and mold.
Protection against high temperature: When the temperature in the power supply
system reaches the specified threshold, the power supply system automatically
reduces the power or shuts down the power amplifier. When the temperature falls
below the threshold, the power supply system restores the normal power output.
