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1.
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What
type of topologies are employed in ON-LINE UPS configurations? |
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To
satisfy the requirements of various applications and from the view
point of criticality in operation, different topologies are employed
in ONLINE UPS. The complexity and sophestication increases in ascending
order.
HOT STAND TYPE CONFIGURATION
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This configuration comprises of two units of UPS's
(named UPS1 & UPS2). When UPS1 is delivering power to the load,
UPS2 remains idle. In case of failure in the inverter of UPS1, static
switch is enabled thereby providing uninterrupted power to the load
through UPS2. UPS1 runs in synchronism with UPS2, ensuring no break
transfer from UPS1 to UPS2. Under healthy conditions, the batteries
get charged through their corresponding rectifiers.
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PARALLEL
REDUNDANT CONFIGURATION |
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UPS1
& UPS2 are paralleled together through a paralleling unit. The
output load is shared equally (50%) by both the UPSs under healthy
conditions. Both the UPS systems are synchronized with bypass. Upon
failure of UPS1, the entire load is taken care off by UPS2 & vice
versa. The bypass static switch is enabled only when the both UPS
systems fail, providing immediate power to load. The batteries are
independently charged through their respective rectifiers. |
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Truth
Table: |
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b
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Static
Switch
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Result
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| UPS1
& 2 healthy |
OFF
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Load
is shared in equal propotion (50%) by both UPS.
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| UPS1
healthy & UPS2 trip |
OFF
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UPS1
handles entire load
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| UPS2
healthy & UPS1 trip |
OFF
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UPS2
handles entire load
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| UPS1
& 2 trip |
ON
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Load
works on Bypass
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CRITICAL
NON-CRITICAL SYSTEM |
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UPS1 & UPS2 deliver power to the critical &
non-critical loads respectively under healthy conditions. UPS1 synchronizes
with UPS2 & UPS2 synchronizes with the bypass. In case of a
critical inverter failure, critical load works on UPS2 through enabled
STSW1, simultaneously transferring the non-critical load to Bypass
by activating STSW3 & inhibiting STSW2. The restoration of the
critical inverter will be responsible for retransferring the loads
of their corresponding inverters. The batteries are charged through
their corresponding rectifiers.
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Truth
Table: |
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b
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STSW1
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STSW2
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STSW3
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Result
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| UPS1
& 2 healthy |
OFF
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ON
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OFF
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Critical
load on UPS1
Non Critical load on UPS2
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| Inv.1
trip & UPS2 healthy |
ON
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OFF
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ON
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Critical
load on UPS2
Non Critical load on Bypass
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| Inv.2
trip & UPS1 healthy |
OFF
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OFF
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ON
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UPS2
handles entire load
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2.
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Is
Online UPS better ? |
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Online UPS provides better overall power protection
to your computers and peripherals. This protection includes power
conditioning, regulated voltage and frequency and zero transfer
time to battery during mains failure.
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3.
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How
do I install my Online UPS? |
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Online UPS needs to be installed under supervision of a qualified
technician.
Your supplier of JET Online UPS can install it for you.
Jet Electro also provides necessary assistance to your electrical
contractor. |
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4.
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What
about After Sales Services? |
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Every
UPS needs to be serviced every 6 months to ensure its proper operation
and battery condition.
We are proud of our
reputation for customer service
We have a range of maintenance plans to suit every customer requirements
from simpler repair to annual service contracts with guaranteed
response time.
And
every customer of JET-ELECTRO has free access to our customer support.
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5.
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What
is Load Crest Factor? |
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A pure sine waveform has a peak value, which is
1.414 times the RMS value indicated on a voltmeter. A resistance
or any linear load connected to such a voltage source draws currents
having similar waveforms and hence has a crest factor of 1.4. As
against this, the non-linear loads as described above may demand
currents whose peak value to RMS ratios are 2 to 5 or more. This
ratio of peak to RMS is termed as the crest factor, and is indicative
of the degree of non-linear load handling capability of the UPS.
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6.
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What
is Static Regulation? |
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A regulated voltage source such as inverter section
of ON-LINE UPS is expected to maintain the voltage at a predefined
level, irrespective of changes in supply, 1.e. DC input voltage
or load current levels. The percentage deviation of the output,
as a result of load or dc input change,after the output voltage
has settled to a new level is defined as the static or steady state
regulation.
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7. |
What
is Dynamic or Transient Regulation? |
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The percentage deviation of the output from its
steady state value immediately following a disturbance such as sudden
change of DC supply voltage or load current is termed as dynamic/transient
regulation. This deviation is generally much larger than the steady
state value specified as voltage regulation, and incidentally is
a measure of the speed of response of inverter control system. Since
by defination this is a transient quantity, not only the deviation
but the time to bring the voltage back to the steady state regulation
level is also an important index of performance. JET ELECTRO's Online
UPS have the Dynamic Regulation on Output voltage.
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