Battery, Charger, Ups System_new

8/12/2019 Battery, Charger, Ups System_new

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AC/DC UPS & BATTERIES

PART 2


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INTRODUCTION

DEFINITION

BATTERY V/S CELL

CELL COMPONENTS


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BATTERY VOLTAGE CAPACITY AND BATTERY RATINGS

SERIES AND PARELLEL CONNECTION


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Control power for switchgears & S/S automation equipment in Electrical system.

Instrumentation system shut down power requirement.


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TYPES OF BATTERY

PRIMARY BATTERIESused only once, irreversible chemical reaction, cheap,

mostly use in flashlights, watches, toys, radios

SECONDARY BATTERIESreversible chemical reaction, mostly use in starting,lighting & ignition of automobiles, engine-generator sets, UPS, traction,

telecommunication etc.


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TYPES OF SECONDARY BATTERIES

Ni-CD BATTERY

LEAD-ACID BATTERY


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Ni-CD BATTERY

CELL CONSTRUCTION
http://localhost/var/www/apps/conversion/tmp/My%20Documents/Battery/Ni-Cd%20Batteries-basic_files/cellconst.jpg


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ELECTROCHEMISTRY

During Discharge :

- At AnodeCd Cd(OH)2 + 2e

- 0.8 Volts

- At Cathode

NiOOH + e- Ni(OH)2 0.5 Volts

During charging reverse reaction will take place.

- Overall reaction :

2 NiOOH + Cd + 2 H2O 2 Ni(OH)2 + Cd(OH)2

Electrode Potential = EOP + ERP

Electrode Potential = 0.8 + 0.5

= 1.3 Volts


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Typical Data for Ni-Cd

Cell type KPM100P

Cell end Volt 1.1 V

Discharge time 30 min

Min. Ambient temperature 0C

Lowest expected electrolyte temp. 0+10C

Temperature de rating factor Shall be taken from the battery curve


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APPLICATIONS

Engine starting

Switchgear Control supply

UPS

Process control Data & Information

Emergency Lighting

Security & Fire Alarm

Switching & Transmission

Signaling


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LEAD ACID BATTERIES

Flooded or wet cell battery

Valve Regulated Lead Acid (VRLA) Battery


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ELECTROCHEMISTRYDuring Discharge :

- At Anode

Pb + HSO4- PbSO4+ 2e- + H

+ 0.356 Volts

- At Cathode

PbO2+ Pb + 2H2SO4 2PbSO4 + 2 H2O 1.685 Volts

During charging reverse reaction will take place.

- Overall reaction :

Pb + PbO2+ 2 H2SO4 2 PbSO4 + 2 H2O

Electrode Potential = EOP + ERP

Electrode Potential = 0.356 + 1.685

= 2.041 Volts


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ELECTROCHEMISTRY

Following reactions form the basis of Lead acid cell chemistry


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Typical Data for Lead-acid

Float Voltage 2.16V-2.25V/Cell

Boost Charging=1000AH rating 14-16 Hrs

Max boost charger voltage 2.75 V/Cell

Equalising charge Voltage 2.33 V/Cell


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Construction

Lead-acid battery plate arrangement

Lead-acid battery construction


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Construction Details


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Comparison between Vented & VRLA batteries

Failure Mechanism

- Dry out

- Thermal runaway

Electrolyte concentration

Float voltage

Absence of free electrolyte

Maintenance

Orientation in Use

Vented Gas


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Selection of VRLA Batteries

Temperature

Charging limitations

Space limitation

Environment Life consideration

Safety

Battery sizing


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Battery sizing calculation Battery duty cycle

Cell size

Equalizing charge

Full float operation Period

Rated capacity

Load classification

- continuous load

- Noncontinuous load- Momentary loads

- other considerations (Random load, etc.)


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Duty cycle diagram


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Factors considered in Battery sizing

Temperature correction factor

Aging factor

Design margin

Capacity rating factor (Kt)

Final battery size = Battery size (which we get from work sheet) x

Temperature correction factor x Aging factor x

design margin

When the battery size is greater than standard battery size, the next larger battery is

required.


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Battery Room & Battery Installation

Battery room should be in corner of substation.

Exhaust fan & water connection to sink.

Floors and walls up to 1.5m height shall have acid/alkaline resistant protective

epoxy coating. Room temperature should be between 5C to 25C.

Maximum temperature between cells & blocks shall not exceeds 10K for ventedand 5K for VRLA type battery.

Lighting fixtures used shall be chemical resistant type and mounted on wall for easyreplacement.

Switching controlling light fittings & exhaust fans shall be installed outside batteryroom.


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Check list after battery installation

Name plate details and number of cells are as per approved drawings.

Sufficient clearance is maintained around battery bank for ease of maintenance.

Acid proof tiles have been provided for lead acid batteries.

An eyewash shower and wash basin are available nearby.

Voltage and specific gravity of all cells are as per manufacturers recommendations.

Cell terminal connections are tight and coated with petroleum jelly.

Stand and cell insulators are clean. Wooden stands are painted with anticorrosive paint.

Cell numbers are properly fixed to cells.

Float level indicators are free.

Gas vent are provided and free from blockage.

Cells have not developed any crack/damage/leak.

Cells are mounted on treated wooden racks and insulated bases.

Suitable drainage has been provided for likely electrolyte spillage.

Acid treatment chart is prominently displayed inside the room.

Cable connection are made with recommended lugs.

Alkaline batteries are not in the same room where lead acid cells are installed.


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BatteryCharger

Scope

Mode (Float & Boost Charging mode)

Type ( Float & Boost Charger)

Input supply voltage

V +/- 10 %

F +/- 5 %

THD < 5 %

3 phase controlled rectifier with protective devices

Parallel redundant-Performance controls

Current Limit, Cell Booster


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Battery Chargersizing

Sizing criteria

Discharge current

Charging hours Efficiency of charger

Average DC load

Capacity rating factor

Trickle charging current of battery

Float charger capacity

Boost chargercapacity


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UPS System Single UPS with bypass

Parallel redundant bypass

Hot standby bypass


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UPS System

UPS- Performance (Spec Cl 5.3.16)

Types of loads (Linear, Non linear)

Load Transfer Bypass F + / - 4 %

FDU (Cl 5.9)


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UPSSIZING

CF= Peak Value/ RMS Value

Based on sum of Load KVA

Sum of (Load X CF)

CF for linear load 1.414 (Check With UPS CF)

Loads and P.F.

Overall PF X UPS rating

Start up current (Inrush)

Remains within permissible limit of Inv Rated Current


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REFERENCES

IEEE std 1115-2000, IEEE Recommended Practice for Sizing Nickel-cadmium

batteries for stationary applications

IEEE std 1189-1996, IEEE Guide for Selection of Valve regulated lead acid

(VRLA) batteries for stationary applications

IEEE std 485-1997, IEEE Recommended Practice for Sizing Lead Acid batteries

for stationary applications

IEEE std 450-1995, IEEE Recommended Practice for Maintenance, Testing, and

Replacement of Vented Lead-Acid Batteries for Stationary Applications

IEEE std 484-1996, IEEE Recommended Practice Installation Design and

Installation of Vented Lead-Acid Batteries for Stationary Applications

OISD-recommended practice-147, Inspection and safe practices during electricalinstallations

DOE-HDBK-1084-95, DOE Handbook Primer on lead acid storage batteries


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THANK YOU