POWER TRANSFORMER REPAIR (CAP: 1.2 NOS/DAY)
[EIRI/EDPR/4504] J.C.: 2720XL
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive.
If a load is connected to the secondary, current will flow in the secondary winding, and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (Vs) is in proportion to the primary voltage (Vp) and is given by the ratio of the number of turns in the secondary (Ns) to the number of turns in the primary (Np) as follows:
By appropriate selection of the ratio of turns, a transformer thus enables an alternating current (AC) voltage to be "stepped up" by making Ns greater than Np, or "stepped down" by making Ns less than Np. The windings are coils wound around a ferromagnetic core, air-core transformers being a notable exception.
COST ESTIMATION
Plant Capacity 1.2 Nos/Day
Land & Building (4000 sq.mt.) Rs. 24.60 Lac
Plant & Machinery Rs. 21.00 Lac
Working Capital for 0.25 Months Rs. 1.21 Lac
Total Capital Investment Rs. 50.69 Lac
Rate of Return 11%
Break Even Point 80%
CONTENTS
INTRODUCTION
PRINCIPLE OF TRANSFORMER
FIGURE 1: RELATIONSHIP BETWEEN CURRENT, MAGNETIC FIELD STRENGTH AND FLUX
FIGURE 2: TRANSFORMER SCHEMATIC
POWER TRANSFORMER
1. THREE PHASE TRANSFORMERS:-
DRY TYPE CAST RESIN TRANSFORMERS USING UNFILLED SYSTEM:-
DETAILS OF POWER TRANSFORMER
CONSTRUCTION
CORE
YOKE SECTIONS
WINDINGS
LOW VOLTAGE WINDING
HIGH VOLTAGE WINDING
COOLING TUBES
OIL TANK
CONSERVATOR
BREATHER
BUSHING INSULATORS:-
BUCHHOLZ RELAY
OIL GAUGE
RELIEF AND EXPLOSIVE VENTS
TAPPING SWITCHES
CHARACTERISTICS OF TRANSFORMER OIL
CHARACTERISTICS
CONSTRUCTION OF TRANSFORMER
(A) OUTER PARTS OF TRANSFORMER
(1) YOKE
(2) BUCHHOLZ RELAY
(3) CONSERVATOR TANK
(4) OIL LEVEL INDICATOR
(5) BREATHER
(6) WINDING TEMPERATURE INDICATOR
(7) COOLING FANS/RADIATOR
(8) SYSTEM GROUND TERMINAL
(9) DRAIN VALVE
(B) INNER PARTS OF TRANSFORMER
(1) CORE
(2) PRIMARY WINDING (HV-WINDING)
(3) SECONDARY WINDING (LV-WINDING)
(4) TRANSFORMER OIL
B.I.S. SPECIFICATION
TESTING OF TRANSFORMER
1. INSULATION RESISTANCE TEST
TEST PURPOSE
TEST INSTRUMENTS
TEST PROCEDURE
2. DC RESISTANCE OR WINDING RESISTANCE TEST
TEST PURPOSE
TEST INSTRUMENT
METHOD NO: 1 (KELVIN BRIDGE METHOD FOR MEASUREMENT
OF WINDING RESISTANCE)
TEST PROCEDURE
KELVIN BRIDGE
METHOD NO: 2 (CURRENT VOLTAGE METHOD OF MEASUREMENT
OF WINDING RESISTANCE)
DC WINDING RESISTANCE TEST (CURRENT-VOLT METHOD)
TEST PROCEDURE
REQUIRED PRECAUTION
TEST ACCEPTANCE CRITERIA
TEST CAN DETECT
3. TURNS RATIO/VOLTAGE RATIO TEST
TEST PURPOSE
TEST INSTRUMENTS
METHOD NO 1 TURNS RATIO TESTING
TEST PROCEDURE
TRANSFORMER TURNS RATIO METER (TTR)
BRIDGE CIRCUIT
TEST CAUTION
METHOD NO 2 VOLTAGE RATIO TESTING
TEST PROCEDURE
TEST ACCEPTANCE CRITERIA
TEST CAN DETECT
TEST INSTRUMENT
TEST PROCEDURE
SHORT CIRCUIT TEST (WITHOUT CT)
SHORT CIRCUIT TEST (WITH CT)
ACCEPTANCE CRITERIA
TEST CAN DETECT
6. OPEN CIRCUIT / NO LOAD TEST
TEST PURPOSE
TEST INSTRUMENTS
TEST PROCEDURE
TEST CAUTION
ACCEPTANCE CRITERIA
7. CONTINUITY TEST
PURPOSE OF TEST
TEST INSTRUMENTS
TEST PROCEDURE
TEST CAN DETECT
8. MAGNETIC CURRENT TEST
TEST PURPOSE
MAGNETIC CURRENT TEST
TEST PROCEDURE
9. MAGNETIC BALANCE TEST
TEST PURPOSE
TEST INSTRUMENT
TEST CIRCUIT DIAGRAM
MAGNETIC BALANCE TEST
TEST PROCEDURE
10. HIGH VOLTAGE TESTS ON HV & LV WINDING
PURPOSE
TEST INSTRUMENT
TEST CIRCUIT DIAGRAM
HV HIGH VOLTAGE TEST
LV HIGH VOLTAGE TEST
TEST PROCEDURE
11. DIELECTRICAL TEST
TEST PURPOSE
TEST INSTRUMENTS
TEST PROCEDURE
METHOD NO 1 (SEPARATE SOURCE VOLTAGE WITHSTAND TEST)
DIELECTRIC TEST (SEPERATE VOLTAGE SOURCE WITHSTAND TEST)
METHOD NO 2 (INDUCED SOURCE VOLTAGE WITHSTAND TEST)
ACCEPTANCE CRITERIA
DIELECTRIC TEST (INDUCED VOLTAGE TEST)
ACCEPTANCE CRITERIA
METHOD NO 3 LIGHTING IMPULSE TEST
12. TEMPERATURE RISE TEST OF TRANSFORMER
MARKET OVERVIEW OF POWER TRANSFORMER
PRODUCT INSIGHTS
REGIONAL INSIGHTS
COMPETITIVE INSIGHTS
POWER TRANSFORMERS MARKET TO RIDE ON INCREASING GLOBAL
ENERGY DEMAND TO REACH US$28.69 BILLION BY 2019
GLOBAL POWER TRANSFORMERS MARKET GROWING
TRANSFORMER REPAIR PROCESS
DRYING
ELECTRIC TEST
METHOD OF REPAIRING TRANSFORMER
REPAIR METHOD AND ORDER OF REPAIR PARTS OF POWER
TRANSFORMER
LIFTING OF COMPONENTS
REPAIR
DRYING OF THE TRANSFORMER
COMBINED LFH- AND HOT OIL SPRAY/VACUUM DRYING PROCESS TECHNOLOGY
TEMPERATURES
DRYING TIME
TESTING
THE MOBILE HIGH VOLTAGE TEST FIELD USED FOR INDUCED
VOLTAGE TEST
THE MOBILE HIGH VOLTAGE TEST FIELD USED FOR APPLIED
VOLTAGE TEST
MOBILE HIGH VOLTAGE TEST FIELD USED FOR MEASUREMENT
OF NO LOAD AND ON LOAD LOSSES
IMPULSE VOLTAGE SYSTEM
POWER TRANSFORMER INSTALLATION, ACCEPTANCE
AND MAINTENANCE PROCEDURE
UNSCHEDULED TRANSFORMER MAINTENANCE
TRANSFORMER ORDINARY MAINTENANCE
PROTECTIVE MAINTENANCE
DRY-TYPE POWER TRANSFORMERS
INSTALLATION
TABLE 1. MAXIMUM 24H AVERAGE COOLING AIR TEMPERATURE (°C)
TRANSFORMER INSPECTION
TRANSFORMER ACCEPTANCE TESTS
TABLE 2. DRY-TYPE TRANSFORMER IR FIGURES
TABLE 3. DIELECTRIC TEST VALUE FOR ACCEPTANCE AND PERIODIC MAINTENANCE OF DRY-TYPE POWER TRANSFORMERS
MAINTENANCE
DRYING-OUT TECHNIQUES
STORAGE
LIQUID-TYPE POWER TRANSFORMER
INSTALLATION
INSPECTION
POWER TRANSFORMER ACCEPTANCE TESTS
TABLE 4. LIQUID-FILLED TRANSFORMER IR FIGURES
TRANSFORMER MAINTENANCE
TABLE 5. TRANSFORMER INSPECTION AND MAINTENANCE PLAN
DRYING-OUT TECHNIQUES
TRANSFORMER STORAGE
POWER TRANSFORMER DIAGNOSTIC GUIDE
TABLE 6. CAUSES OF TRANSFORMER DAMAGE
TESTING DETAILS FOR POWER TRANSFORMER
TESTING
LOAD LOSSES
IMPEANCE VOLTAGE MEASUREMENT
MEASURE OF WINDING RESISTANCE
MEASUREMENT OF INSULATION RESISTANCE
HIGH VOLTAGE TEST
INTER -TURN INSULATION TEST
SUPPLIERS OF RAW MATERIALS
SUPPLIERS OF HOT ROLLED SHEETS
SUPPLIERS OF M.S CHANNELS AND ANGLES
SUPPLIERS OF M.S. FLAT
SUPPLIERS OF M.S. PLATE
SUPPLIERS OF M.S. PIPE
SUPPLIERS OF CARGO LAMINATION
SUPPLIERS OF DPC COPPER WIDING WIRE
SUPPLIERS OF TRANSFORMER OIL
SUPPLIERS OF CRAFT PAPER
SUPPLIERS OF M.S BOLTS AND NUTS
SUPPLIERS OF TRANSFORMER BUSHINGS
SUPPLIERS OF PAINT
SUPPLIERS OF PLANT AND MACHINERIES
SUPPLIERS OF TRANSFORMER COIL WINDING MACHINE
SUPPLIERS OF OIL FILTER MACHINE
SUPPLIERS OF VACCUME IMPREGNATION PLANT
SUPPLIERS OF ELECTRICAL MEASURING INSTRUMENT
SUPPLIERS OF TRANSFORMER OIL TESTING KIT
SUPPLIERS OF BENCH GRINDER
SUPPLIERS OF DRILLING MACHINE
SUPPLIERS OF SHEARING MACHINE
SUPPLIERS OF WELDING MACHINE
SUPPLIERS OF AIR COMPRESSORS
SUPPLIERS OF MATERIAL HANDLING EQUIPMENTS
SUPPLIERS OF PAINTING EQUIPMENTS
SUPPLIERS OF FIRE FIGHTING EQUIPMENTS
SUPPLIERS OF EOT CRANE
SUPPLIERS OF AIR POLLUTION CONTROL EQUIPMENTS
SUPPLIERS OF PLATEFARM WEIGHING MACHINE
SUPPLIERS OF SHOT BLASTING MACHINE
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)
