Fundamentals, Selection and Sizing of Standby Batteries

7/24/2019 Fundamentals, Selection and Sizing of Standby Batteries

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Fundamentals, Selection and Sizing

of

Standby Storage Batteries

4 February 2010


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4 February 2010

Standby Batteries In Generating Stations & Substations

Application :

-- Unit Battery

Substation Battery

PLCC

24/26v C & I Battery

UPS Battery

Battery for VHF set


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4 February 2010

Battery Is Considered To Be The HEART Of The

Power Plant Battery provides the ultimate and final DC back-up for

operating emergency equipment which power the turbogenerators (viz. emergency oil pumps etc.)

DC power for operation of all switchgear, protectionrelays, indicating lamps and facia

Power for emergency lighting within the generatingstation building

Uninterrupted power for controlling C & I equipment and

associated ups systems Power for vital communication equipment (plcc),

essential for re-synchronising the unit with the grid orfor reviving the grid in the case of a major grid failure


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4 February 2010

What If The Battery Fails In An Emergency

Unit Battery

The emergency oil pump will not operate which may

lead to the seizure of rotor bearings

Loss of hundreds of crores of rupees towards repairingthe rotor and generation revenue loss while the unit is

out of commission

Switchgear associated with generator may not trip

which can lead to generating transformer damage

Failure of instrumentation and control

Total darkness in the powerhouse


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4 February 2010

What If The Battery Fails In An Emergency (contd.)

Substation

Switchgear and relays will not operate causing

extensive damage to transformers and power lines

PLCC

Extremely difficult to resynchronise the unit with the

grid

Major setback in the process of reviving the grid in the

event of a regional grid failure

If the battery fails while the unit is in operation, it may

become essential to shutdown


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4 February 2010

The Single Most Important Feature Of Storage Batteries For

Power Sector and Other Critical Standby Application Is

Reliability

Reliable standby power source

Deliver power as and when called for

Full capacity at any point of time in service lifePredictability


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EITHER

SUDDEN DISRUPTION OF MAINS POWER TAKES PLACE

OR

CONVENIENT AVAILABILITY OF MAINS POWER IS NOT THERE

THIS CLEARLY DEFINES TWO REGIMES OF APPLICATION

STANDBY APPLICATION

CYCLIC APPLICATION

UPS, INVERTERS, TELEPHONE

EXCHANGES, POWER STATIONS,

SWITCHING

CELL PHONES, TOYS, FORK

LIFTS, ELECTRIC VEHICLES,

SOLAR PHOTOVOLTAICS

STORAGE BATTERY

WHEN ?

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SELECTION HEURISTICS

SELECTION OF RIGHT

TECHNOLOGY

KNOWLEDGE OFATTRIBUTES OF

COMPETING

TECHNOLOGIES

KNOWLEDGE OF

ATTRIBUTES OF

DESIGN OPTIONS

KNOWLEDGE OF

APPLICATION

REQUIREMENTS

CALCULATION OFCORRECT CAPACITY

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LEAD ACID

NICKEL CADMIUM

General Battery Technologies

Most Popular Electrochemical Couples used worldwide in

Industrial Application

4 February 2010


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BASIC ELECTROCHEMISTRY

PbO2 + Pb + 2H2SO4 PbSO4 + PbSO4 + 2H2O

CHARGED DISCHARGED

ELECTROLYTE TAKES ACTIVE PART IN REACTIONSPECIFIC GRAVITY

CHANGES WITH STATE OF CHARGEEASY MONITORING AND INDICATION

OF STATE OF CHARGE (SOC)

2NiOOH + 2H2O + Cd 2Ni(OH)2 + Cd(OH)2NEG. NEG.POS POS

DISCHARGEDCHARGED

ELECTROLYTE DOES NOT TAKE ACTIVE PART IN REACTIONSPECIFIC

GRAVITY DOES NOT CHANGE WITH STATE OF CHARGENO DIRECT &

EASY METHOD OF MEASURING STATE OF CHARGE

NEG. NEG.POS POS

LEAD ACID

NICKEL CADMIUM

4 February 2010


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More than 90% of applications world-wide use

Lead-acid

Reasons:

LOW COST

APPLICATION VERSATILITY

ABUNDANT RAW MATERIAL

WELL DEVELOPED SERVICING RECYCLING

INFRASTRUCTURE

Advantage Lead Acid

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Technology Wise Categorisation

Industrial Lead Acid Battery

FLOODED VRLA

FLAT TUBULAR PLANTE

The Lead-Acid Technology

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LEAD ACID BATTERY AN OVERVIEW

ACTIVEMATERIAL

TAKES ACTIVE PART IN

REACTION TO STORE &SUPPLY ENERGY

SUPPORT

STRUCTURE

ENABLES ELECTRONIC

CONDUCTION1

2

PROVIDES MECHANICAL

SUPPORT TO ACTIVE

MATERIAL

ACTIVE MATERIAL

SUPPORT STRUCTURE

PLATES ARE

CONSTITUTEDOF

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FLAT PLATE DESIGN

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FLAT PLATE MORPHOLOGY

A CHEMICAL BONDING HOLDS THE ACTIVE

MATERIAL IN PLACE THROUGHOUT THE

SERVICE LIFE

WIRE-MESH LIKE SUPPORT

STRUCTUREGRID CAST OF LEADALLOY, ANTIMONY OR CALCIUM

ACTIVE MATERIAL

PASTED ON GRID -EXTERNALLY

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FLAT POSITIVE PLATE

MOST SUITABLE FOR HIGH CURRENT, SHORT DURATION

APPLICATION viz. SLI, SHALLOW DUTY INVERTER ETC.

ADVANTAGES

MINIMUM LEAD MOST ECONOMIC & HIGHESTENERGY DENSITY

EXCELLENT HIGH RATE

DISCHARGE PERFORMANCE

AND CHARGE ACCEPTANCE

LARGE ACTIVE

SURFACE AREA

LIMITATIONS

ACTIVE MATERIAL

SHEDDINGLIMITED CYCLING

CAPABILITY

EASY ACCESS OF

ACID TO LEAD GRIDEASY CORROSION LOW

LIFE EXPECTANCY

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TUBULAR PLATE DESIGN

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TUBULAR POSITIVE PLATE MORPHOLOGY

SPINE

PLASTIC BOTTOM BARGAUNTLET

ACTIVEMATERIAL

GAUNTLET + BOTTOM BAR + LEAD TOP BAR

RETAINS THE ACTIVE MATERIAL

LEAD TOP BAR

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EXTENDED SERVICE LIFE. IT IS DESIGNED FOR DEEP CYCLING

LOOSE PACKING OFACTIVE MATERIAL

POSSIBLE

ADVANTAGES

NO ACTIVE MATERIALSHEDDING

BEST SUITED FORCYCLING1500 CYCLES

@ 80% DOD

SPINE DEEPLY

EMBEDDED IN ACTIVE

MATERIALLOW SPINECORROSION

EXTREME TEMPERATURE

OPERATION

RESISTANT TO OVER-

CHARGE

RECOVERY FROM DEEP

DISCHARGE

PSOC OPERATION

TUBULAR POSITIVE PLATE WHY ?

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MODEST HIGH RATE DISCHARGEPERFORMANCE.

REQUIRES PERIODIC EQUALIZING AND/OR

BOOST CHARGING

REQUIRES PERIODIC TOPPING UP

ANTIMONY POISONING LEADS TO SLOWLYDECLINING VOLTAGE PROFILE AND

INCREASING WATER LOSS AS THE BATTERY

AGES.

TUBULAR POSITIVE PLATE WHY NOT ?

LIMITATIONS

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TUBULAR

Are all the Tubulars

Same ??

The answer is an emphatic NO !!!

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Exide OPzS

The Next Generation Tubular Battery

4 February 2010


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HIGH PRESSURE SPINE CASTING IN HADI MACHINES

GRAVITY CAST (1 Bar) CAST IN LOW PRESSURE (10 Bar) CAST IN HADI (100 Bar)

Exide has introduced a unique hybrid concept in this country. Lowantimonial positive spine alloy with lead-calcium negative. This togetherwith the benefit of Hadi casting leads to:

Extremely Corrosion Resistant Positive Alloy

Drastically reduced water loss

Exide OPzS comes with Heavy Duty DIN standard Spines

Exide OPzS

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Comparative Water Loss study data:

Positive

Spine Alloy

Negative

Grid Alloy

Rate of water loss on float # per

Ah/Cell/21 days at 50oC, 2.4 V/cell

Till late 80 9% Sb 5% Sb 1.10 gms.

Post 90 5% Sb 2.5% Sb 0.55 gms

Exide OPzS 2.5% Sb 0.1% Ca

0.3% Sn

0.18 gms

# Test Specification as per RDSO low maintenance battery requirements

In the absolute worst case too, cells do not require topping up in 1 year!!

Exide OPzS

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The Exide OPzS range of Tubular CellsNow come in transparent, tough Styrene-Acrylonitrile (SAN) boxes clear as glass.

Exide OPzS

Easy to monitor State-of-Health !!

Additional Features

Ceramic Dome Filter

Plastic Encapsulated

Strap for corrosionresistance

Low foot print

Insulated Connectors

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PLANTE PLATE DESIGN

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EXIDE PLANTE

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PLANTE


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CAST OF 99.99%

PURE LEAD

LAMELLAR GRIDSTRUCTURE

ENHANCED

ACTIVE SURFACE

AREA

INTEGRAL GRID

ACTIVE MATERIAL

PLANTE MORPHOLOGY

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PLANTE HANGING PLATE DESIGN


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POSITIVE PLATE HANGING FROM

CONTAINER SHOULDER

GAP BETWEEN POSITIVE PLATE

BOTTOM & MUD RIB FOR CREEP

GROWTH ALLOWANCE

POSITIVE PLATE

HANGING FROM

CONTAINER SHOULDER

TO PROVIDE SPACE FOR

CREEP GROWTH

INEVITABLE TO PURE

LEAD POSITIVE

PLANTE HANGING PLATE DESIGN

4 February 2010

I t l G id A ti M t i l


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1. In case of loss of active material due to shedding, nextlayer of pure lead is converted to lead-dioxide therebyensuring no loss of capacity feature of continuousregeneration of active material.

2. Across its life time Plante cells therefore perform at fullcapacity there is no aging unlike all other lead-acidproducts.

3. No aging factor required for capacity calculation

Integral Grid-Active Material

4 February 2010


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FLOATCURR

ENT

SERVICE LIFE

10 A

20 Yrs.

Plante

10yrs

SbCdVRLA

Low Sb Tubular

NormalTubular

FLOAT CURRENT VS SERVICE LIFE

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CONTINUOUS REGENERATION OF ACTIVE MATERIAL

PLANTE NO LOSS IN CAPACITY

TOTAL LEAD-DI-OXIDE CONTENT FAIRLY

CONSTANT THROUGHOUT THE LIFE

SPAN INDICATING A CONSTANT

CAPACITY OUTPUT

CAPACITY DEGRADATION OVER LIFE AGEING FACTOR

TUBULAR : 20% 1.25

VRLA : 20% 1.25

Ni-Cd : 20% 1.25

PLANTE : ZERO 1.00

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HIGH SURFACE AREA

HIGH CHARGING RATES POSSIBLE.

CHARGING AT 0.25 C10 AMPS UPTO

2.4 VOLTS PER CELL WITHOUTPROBLEM

NO ANTIMONY POISONING

HIGH FLOAT POTENTIAL POSSIBLE.

PLANTE FAST RECHARGE

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LIFE EXPECTANCY OF 15 TO 20 YEARS PLUS.

PLANTE LONG LIFE

VERY THICK POSITIVE ENOUGH CUSHION AGAINST

CORROSSION

LOW SUSCEPTIBILITY TO OVERCHARGE DUE TO

VERY LOW EQUILIBRIUM FLOAT CURRENT OFTHE ORDER OF 1 mA/AH UNDER NORMAL FLOAT

CONDITION

LOW FLOAT CURRENT AND HIGH PURITY OF LEADLOWERS THE CORROSSION RATE

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RELIABILITY - REITERATED

PLANTE EASY MONITORING

TRANSPARENT SAN (STYRENE ACRYLONITRILE)

CONTAINER EASY VISUAL MONITORING OF CELL INSIDE

ANY ODD BEHAVIOUR CAN BE MONITORED ANDCORRECTED MUCH BEFORE IT SHOWS UP AS A

FAILURE MODE

EASY CLEANING OF CELLS FROM UNAVODABLE

SLUDGE DEPOSITION TO AVOID SHORT CIRCUITAND RELATED TROUBLES

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VRLA DESIGN

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SEALED ! CAN BE KEPTIN ANY ORIENTATION.

NO TOPPING-UP REQUIRED

EVER MAINTENANCE-FREE.

A ZERO EMISSION PRODUCT.

BATTERY COMES CHARGED.

COMPACT.

WHAT IS VRLA ?

4 February 2010

Advantage VRLA


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1. No topping up ever2. No emission of fumes3. Supplied factory charged4. Excellent high rate discharge performance5. Excellent charge acceptance6. Excellent deep cycle life7. Low Self-discharge8. Designed to suit float and moderate cyclic duty

9. Compact low foot print10.Long Life

Advantage VRLA

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The Oxygen Recombination Cycle


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+ -

H + H +

At +ve Electrode At -ve Electrode

H2O=1/2O2 + 2H

+ +2e- 2Pb + O2= 2PbO (Exothermic Reaction)PbO + H2SO4 = PbSO4 + H2O (Exothermic Reaction)

PbSO4 + 2e- + 2H+ = Pb + H2SO4 (Electrochemical Reaction)

Charger

MECHANISM DURING CHARGING

FLOODED SYSTEM

O2 H2

e-

i

+ -

H + H +

Charger

e-

i

V R L A

SYSTEM

O2

O2

2Pb + O2= 2PbO

PbO + H2SO4= PbSO4 + H2O

PbSO4 + 2e-

+ 2H+

= Pb + H2SO4

ABSORPTIVE SEPERATOR - ELECTROLYTEELECTROLYTE - H2SO4

The Oxygen Recombination Cycle

RECOMBINATION MECHANISM OF VRLA CELLS WITH MICRO GLASS

SEPERATORS IN COMPARISON WITH FLOODED CELLS

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Venting Arrangement Of A VRLA Battery


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VRLA Limitations


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1. No means of state-of-charge assessment

2. Vulnerable to prolonged operation at high temperature

3. Sensitive to both under and over charge

4. Recovery from over discharged condition is difficult

5. Can have a catastrophic failure in case of chargermalfunction and/or abnormally high temperatureoperation a failure mode known as thermal runaway

VRLA Limitations

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SIZING FACTORS PARAMETERS

PRIMARY

LOAD CURRENT

LOAD DURATION

NOMINAL SYSTEM VOLTAGE

MINIMUM SYSTEM VOLTAGE

MINIMUM OPERATING TEMPERATURE

DESIGN MARGIN

AGEING FACTOR

SECONDARY

FACTORS SPECIFIC TO APPLICATION

4 February 2010

Selection Parameters


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DEPTH OF DISCHARGE

FREQUENCY OF DISCHARGE

APPLICATION CRITICALITY

CHARGING CONSTRAINT

MAINTENANCE CONSTRAINT

OPERATING CLIMATIC CONDITIONS

SELECTION OF THE RIGHT TYPE OF TECHNOLOGY AND

DESIGN PRECEDES THE SIZING EXERCISE

PARAMETERS

TO BE

CONSIDERED

FOR SELECTION

4 February 2010

Selection Summary


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APPLICATION

ATTRIBUTE

HIGH MODERATE LOW

DEPTH OF

DISCHARGETUBULAR

TUBULAR /

VRLA

VRLA /

PLANTE

FREQUENCY OF

DISCHARGETUBULAR

TUBULAR /

PLANTE

PLANTE /

VRLA

CRITICALITY OFAPPLICATION

PLANTE PLANTE /TUBULAR

TUBULAR /VRLA

CHARGER

CONSTRAINT ON

VOLTAGE

TUBULAR - -

MAINTENACECONSTRAINT

VRLA PLANTE /TUBULAR

PLANTE /TUBULAR

OPERATING TEMP.TUBULAR /

PLANTEPLANTE / VRLA VRLA

Selection Summary

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BATTERY SIZING

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Sizing Parameters


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g

APPLICATION

PARAMETERS

DUTY CYCLELOAD CURRENT

AND DURATION PATTERN

OPERATING DC BUS VOLTAGE

WINDOWMAXIMUM & MINIMUM

DC BUS VOLTAGES

MINIMUM AMBIENT TEMPERATURE

DESIGN MARGIN

BATTERY

PARAMETERS

CHARGING VOLTAGE REQUIREMENT

DISCHARGE CHARACTERISTICS

FACTOR FOR AGING PHENOMENON

FACTOR FOR STATE-OF-CHARGE IF

REQUIRED

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STEP1 : CALCULATION OF NUMBER OF CELLS


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CHARGING

VOLTAGE PER CELL

VC

MAX. DC BUS

VOLTAGE VMAX

NOMINAL VOLTAGE

PER CELL, V

NOMINAL DC BUS

VOLTAGE VDC

NUMBER OF CELLSVMAX / VC

VDC / V

MIN. DC BUS

VOLTAGE VMIN.

END OFDISCHARGE

VOLTAGE

(ECV)

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STEP2 : CALCULATION OF BASIC CAPACITY


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CAPACITY FACTOR

F

BASIC RATED CAPACITY OF THE CELL

C = I X F

LOAD CURRENT, I

END OF DISCHARGE

VOLTAGE

TYPE OF CELL

SELECTED

BACK-UP DURATION

REQUIRED

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STEP3 : CALCULATION OF FINAL CAPACITY


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BASIC RATED CAPACITY OF THE CELL

C = I X F

FINAL CALCULATED CAPACITY

CF = C X A X D X KTX Z

FACTOR FOR AGING,

A

FACTOR FOR

TEMPERATURE

CORRECTION, KT

DESIGN MARGIN, D

STATE-OF-CHARGE /

FLOAT CHARGE

CORRECTION

FACTOR, Z *

* REQUIRED ONLY FOR Ni-Cd BATTERY

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Multi-step Load


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p

P = PERIOD

S = SECTION

Sn = Pn

CS = (A PA P-1) X FTP = 1

P = S

C = MAX. CSS = 1

S = N

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SOFTWARE ALGORITHM


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BATTERY SIZINGTOOLKIT

SELECTED

MODEL

NO. OF

CELL

USERS

CONFIRMATION

ENVIRONMENT

PARAMETERS

SYSTEM

PARAMETERS

LOAD

PARAMETERS

BATTERY TYPE

SELECTED

SIZING CALCULATION

GUARANTEED TECH PARTUCULARS

STANDARD LAYOUT

PRODUCT CATALOGUE

O & M MANUAL

4 February 2010


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THANK YOU

4 February 2010

Documents

Fundamentals, Selection and Sizing of Standby Batteries