2. UPS maintains a continuous supply of electric power to connected
equipment by supplying power from a separate source when utility power
is not available.
It differs from an auxiliary power supply or standby generator, which does
not provide instant protection from a momentary power interruption
WHATISUPS?
3. DEG powers the emergency loads of the plant & UPS in case of power
failure.UPS powers control system during DEG starting so that there is no
interruption during power failure.
Incase of DEG failure, UPS is used to bring the plant process to safe shut
down.
It mainly turns off the critical valves.
WHYUPS?
5. UPS @
Battery location : Battery room in CCR
UPS location : Cabinet room in CCR
Backup time: 30 min
Charging time : 8 hours
Quantity:Two ( 48 KW for UL-II, 15KW for PVC-II)
6. Redundant
125% overload for 10 min, 150% for 1 min and 250% for 20ms.
Two battery units. 48KW UPS has 320 battery units(200AH each) while
16KW has 400 units each(50AH).
Voltage inspection range : -15% to +30%
Local and remote indication/alarm of any failure
CHARACTERISTICS
7. Redundant equipment in separate cubicles to allow maintenance without
interruption.
Battery connection to UPS is through an isolating switch in UPS cabinet.
Cooling : low velocity forced air (redundant fans)
Maintenance bypass s/w is in separate enclosure from ups cabinet, so ups
can be completely removed.
Power : EMCC/MCC buses
CHARACTERISTICS
13. •Full load heat soak run
•Overload tests
•Step Load application
•Steady state regulation
•Charger and inverter current
limiting
•Input inrush current measurement
•Load changeover
TESTS
•Measurement of maximum input
current
•Harmonic distortion
•Non linear load simulation
•Protection co-ordination
•functional, alarm and tripping
check
•Operation of all equipment.
17. UPSACLOAD
• Operator workstation
• Marshalling cabinet
• Emergency panel
• Server
• Color and B/W
printers
• Local control box
• Instrument dc power
DB
Power
to DCS
18. UPSFIELDDISTRIBUTION
• Mass flow meters
• magnetic flow meters
• Ultra sonic meters
• Cod analyzers
• PH analyzers
• HCL concentration
• Weighing
instruments
• Solenoid valve
UPS
field
supply
21. DCPOWERCHARACTERISTICS
A UPS designed for powering DC equipment is very similar to an online
UPS, except that it does not need an output inverter.
DC power is from a separate UPS without an inverter.
It powers the MV switch gear control of General substation, PVC-II
substation and EDCVCM substation.
One DCP is at General Substation (30 KW) and other smaller DCP is at PVC-
II Substation (4KW) next to DEG room.
22. DCP installed in GSS
Control protection
GSS Bus-
A, Bus-B,
Bus-C,
EMEC Bus
EDC/VCM
Bus-I, Bus-
II
CCR DC-
DB
Power for switch on
GSS Bus-
A, Bus-B,
Bus-C,
EMEC Bus
EDC/VCM
Bus-I, Bus-
II
STG lube
oil pump
Power for
DEG
DCPLOAD
30. BATTERY
•Storage batteries are the energy source for UPS systems during
a power outage. UPS systems demand a high discharge rate for
a relatively short time at a constant power and require relatively
good regulation of output voltage.UPS storage batteries are
made up of a string of series-connected cells to achieve the
voltage in the range between 48-400V.
•The two major categories of storage batteries used in UPS are
nickel-cadmium (NiCd) and lead acid.The lead-acid battery is
one of the most inexpensive, most reliable and most widely used
storage batteries.The NiCd batteries have a much greater cycle
life than the lead-acid type, but they cost about 4-6 times more
than lead-acid batteries.
•For a given battery capacity, a NiCd battery is smaller and
lighter than a comparable lead-acid battery
31. STATIC TRANSFER SWTICH
•UPS can maintain supply to load either from the UPS Inverter
output or from the mains (bypass) supply.
•The static switch of an on-line UPS has two operational states,
‘on UPS’ (the normal condition) and ‘on bypass’. In both cases it
provides a very fast transfer between the inverter output and the
bypass.The decision is made by the static switch’s own and/or
the UPS control logic which continually monitors the bypass
(mains) and inverter voltages.The control logic typically controls
the phase and frequency of the UPS inverter(s) to ensure that
the bypass and inverter voltages are in phase (synchronised)
with each other. Bi-directional, break-free transfer between the
two supply sources is only possible when the bypass and the
inverter are ‘synchronised’.
33. STATIC TRANSFER SWTICH
During normal operation, with the inverter supplying the load,
SCRs 3 and 4 are triggered and SCRs 1 and 2 are not triggered. In
the event of an inverter supply problem the static switch
monitoring circuitry would identify it and decide to transfer load.
It stops triggering SCRs 3 & 4 and starts triggering SCR 1 and 2.
Once an SCR is triggered it continues to conduct until the
voltage across it is zero. By triggering SCRs 1 and 2 while SCRs 3
and 4 are still conducting, the bypass and inverter are paralleled
for a short time. Such short term paralleling ensures a break-free
transfer between the two supplies and it is for this reason that
the two supplies must be synchronized before the transfer can
take place. If the transfer was allowed regardless of the
synchronization status of the two supplies then the load would
almost certainly be subjected to a power disturbance.
