COMPONEMTS OF D



BATTERY CHARGER

SHORT CORSE

PREPAIRED BY

NASIR GHAURI

A.M TSG

COMPONEMTS OF D.C SYSTEM

i) BATTERY

ii) BATTERY CHARGER

iii) D.C DISTRIBUTION BOARD

BATTERIES

TYPES OF BATTERIES

i) PRIMARY BATTERIES

ii) SECONDRY BATTERIES

PRIMARY BATTERIES

Non rechargeable cells known as Primary cells.

SECONDRY BATTERIES

Battery cells can be recharged because the chemical reaction that occurs during discharge can be reversed by applying a reverse current into the cell. The cell can be discharged and recharged many times (often many thousand times) before it is degraded to the point where it can no longer provide reliable service.

LEAD-ACID BATTERIES

It is also called a ‘wet-cell’ or ‘flooded-cell’ battery because the electrolyte is in a liquid form. They are vented batteries because the charging process can produce gasses of hydrogen and oxygen which needs to be able to escape from the confines of the battery case. In its charged state the (positive plates) are lead peroxide, the (negative plates) are lead, and the electrolyte is dilute sulphuric acid. As the cell is discharged the plates are converted to lead sulphate and the electrolyte becomes water. The chemical reaction looks like this

PbO2 + Pb + 2H2SO4 ↔ 2PbSO4 + 2H2 + ½O2

Sealed Lead Acid (SLA) Batteries

Type of lead acid battery which is more common because of the reduced maintenance requirements. More correctly, Called a valve regulated lead-acid battery, because they do have a valve to release internal gas build up which can result from overcharging. The electrolyte has been jellified making the battery more resistant to extreme temperatures, vibration and shock. This is also why they are sometimes called ‘Gel Cells’. They also have calcium included in the plate construction which reduces the gassing effects, minimising loss of electrolyte.

CHEMICAL COMPOSITION OF LEAD-ACID BATTERIES

i) POSITIVE PLATE PbO2

ii) NAGETIVE PLATE Pb

iii) SULPHURIC ACID AS AN ELECTROLYTE H2SO4

CHEMICAL REACTION LEAD-ACID BATTERIES

PbO2 + Pb + 2H2SO4 ↔ 2PbSO4 + 2H2 + ½O2

Lead acid batteries have reduced life expectancy if they are left in a discharged condition. Ordinarily they do not deal well with deep discharge cycles

CHARGING REQUIRMENTS OF BATTERIES

i) INITIAL / AFTER CAPACITY TEST CHARGING

ii) FLOAT CHARGING

iii) BOOST CHARGING

iv) PERIODIC / EQUALIZING CHARGING

INITIAL / AFTER CAPACITY TEST CHARGING

CHARGING RATE SHOULD BE MANTINED AS PER MANUFACTURER INSTRUCTION WHICH IS APPROXIMATLLY 7% OF AMPER HOUR CAPACITY

FLOAT CHARGING

CHARGING VOLTAGE THAT COUNTERACTS SELF DISCHARGE

A battery is said to float when charging voltage is slightly greater than the open circuit voltage of the battery.

Note: Charge batteries continuously at the float voltage recommended by the manufacturer

BOOST VOLTAGE

AFTER DISCHARGE, THE BATTERY IS RECHARGED AT HIGHER CHARGING RATE

Condition For Boost Charge

1. Following heavy discharge.

2. If specific gravity (corrected for temperature) of any cell is more than 10 points (0.010) below the full charge value while on float.

3. If the voltage of any cell is more than 0.04 volt below the average cell voltage when the battery is on float.

4. If the level in any cell or cells falls at or near the minimum fill line a lot of distilled water must be added to restore the level to the maximum fill line. If this condition occurs, an equalizing charge must be performed to

restore specific gravity.

PRIODIC / EQUALIZING CHARGE

CORRECTIVE TYPE OF CHARGE THAT BRINGS ALL CELLS UP TO FULLY CHARGE CONDITION.

IT IS APPLIED AFTER INITIAL CHARGE, CAPACITY TEST AND A SPACIFIC PERIOD. THE VOLTAGE LEVEL IS KEPT EQUIVALENT TO THAT OF BOOST CHARGE.

The purpose of the equalizing charge is to ensure that every plate in every cell is brought with certainty to a state of full charge by a slight overcharge.

TEMPERATURE

Higher temperatures reduce the operational life. Lower temperatures reduce the available capacity. If the battery operating temperature is different from 77°F, a correcting factor is to be applied to capacity value taking into account discharge time. (Reference IEEE-450-2010)

The permissible operating temperature range is 5°F to 130°F, The recommended operating temperature range is 68°F to 77°F. This will maximize life and minimize maintenance.

Operating Temperature Recommended Applied Float Voltage VPC

(Haze Battery)

Temperature Voltage Range

0 - 9 2.33 - 2.35

10-14 2.30 - 2.33

15-19 2.27 - 2.30

20-24 2.27 - 2.30

25-29 2.25 - 2.27

30-34 2.23 - 2.25

35-40 2.21 - 2.23

All technical data relates to a rated temperature of 77°F( 25°C).

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ELECTROLYTE

Electrolyte is a diluted sulfuric acid. The nominal S.G. of the electrolyte at 77°F. The maximum deviation is +/-.01g/cm3.Higher temperatures will decrease electrolyte density, while lower temperatures increase electrolyte density. The correction factor is .001 for each 3°F. For each 3°F over 77°F, add .001 to the S.G. reading. For each 3°F below 77°F, subtract .001 from the S.G. reading.

Storage

Store the batteries in a dry, clean and preferably cool and frost-free location. Do not expose the cells to direct sunlight.

►Note: Failure to observe these conditions may result in reduced capacity and service life as well as voiding the battery warranty.

BATTERY CHARGER

A DEVICE WHICH IS USED TO MAINTAIN BATTERY AND LOAD UNDER ALL OPERATING CONDITIONS

PARTS OF BATTERY CHARGER

i) MAIN TRANSFORMER

ii) BRIDGE RECTIFIRE

iii) LC FILTER

iv) BLOCKING DIODE

v) FREE WHEELING DIODE

vi) LOAD VOLTAGE CONTROL CIRCUIT

vii) FIRING CIRCUIT

viii) PROTECTION CIRCUIT

Main Transformer

Main purpose of transformer is isolation between AC to DC and also used to reduce voltage

Bridge Rectifier

Converts A.C into D.C

Half-wave Centre-tap Bridge 3Ø Bridge

Rectification 0.405 0.81 0.81 0.968

ratio – η

LC Filter

Purpose of LC Filter is Harmonic suppression

Blocking Diode

Used to protect from Reverse Power

Free Wheeling Diode

Used for Reverse Recovery

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DRAWINGS

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D.C DISTRIBUTION BOARD

HOLDS ALL PROTECTIONS, CONTROLS AND OPERATIONS

TYPE-A

Battery Battery Distribution

Charger Board

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TYPE-A

Battery Battery Distribution

Charger Board

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█Coupler C.B

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Battery Battery Distribution

Charger Board

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