UPS and DC power training Presentation

UNINTERRUPTIBLE POWER

SUPPLY (UPS)

ABDUL HASEEB SIDDIQIINTERNEE, NED UNIVERSITY

hasboo86@gmail.com www.hasboo.co.nrJULY, 2008

ENGRO POLYMER & CHEMICALS LTD

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

WHAT IS UPS ?

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.

WHY UPS?

UPS CHARACTERISTICS

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)

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

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

OPERATING MODES

NORMAL MODE

Battery

Static switch

bypass

Bypass

supply

UPS

BACKUP MODE

Battery

Static switch

bypass

Bypass

supply

UPS

BYPASS MODE

Battery

Static switch

bypass

Bypass

supply

UPS

MAINTENANCE MODE

Battery

Static switch

bypass

Bypass

supply

UPS

•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.

UPS LOADS

General substation

PVC-II S/S

PVC-IIMastery IP 16KW

UT-IIDelphys MP Elite 48KW

POWER TO UPS

CCR

MAIN DISTRIBUTON

UPS consumers

AC (DCS )

DC (24V to field instruments)

UPS AC LOAD

• Operator workstation• Marshalling cabinet• Emergency panel• Server• Color and B/W printers• Local control box• Instrument dc power DB

Power to DCS

UPS FIELD DISTRIBUTION

• Mass flow meters• magnetic flow meters• Ultra sonic meters• Cod analyzers• PH analyzers• HCL concentration• Weighing instruments• Solenoid valve

UPS field supply

Field instrument area wise

Feedstock (6100)

Polymerizer

(6200)

Drying unit(630

0)

Cooling water unit

(4400)

Dematerialized water

unit (4600)

FIELD DISTRIBUTION

UNINTERRUPTIBLE DC POWER @

DC POWER CHARACTERISTICS

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 EDC\VCM substation.

One DCP is at General Substation (30 KW) and other smaller DCP is at PVC-II Substation (4KW) next to DEG room.

DCP installed in GSS

Control protectionGSS Bus-A,

Bus-B,

Bus-C,

EMEC

Bus

EDC/

VCM

Bus-I,

Bus-II

CCR DC-DB

Power for switch onGSS

Bus-A, Bus-B, Bus-C, EMEC Bus

EDC/VCM Bus-I, Bus-II

STG lube oil pump Power for DEG

DCP LOAD

TYPES & COMPONENTS

POWER PROBLEMS 

Voltage sag 

Voltage spike

Under-voltage

(brownout) 

Over-voltage

Line noise

Frequency

variation 

Switching transient 

Harmonic distortion

TYPESOFFLINE

LINE INTERACTIVE

ONLINE

OFFLINE OR STANDBY UPS

LINE INTERACTIVE UPS

ONLINE UPS

BATTERY & STATIC SWITCH

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

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’.

STATIC TRANSFER SWTICH

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.

THANKYOU!