DISTRIBUTION TRANSFORMER
[EIRI/EDPR/4391] J.C.: 2587XL
INTRODUCTION
The Distribution Transformers are important links in the chain of power distribution systems. The power, which is transmitted at high voltage, stepped down with these distribution transformers. These are manufactured in a variety of capacities and voltage ranges. The demand for Distribution Transformers is basically related to power generation programme envisaged for the country and the rural electrification. The demand for these transformers is likely to increase considerably.
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.
Transformers range in size from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge units weighing hundreds of tons used to interconnect portions of power grids. All operate on the same basic principles, although the range of designs is wide. While new technologies have eliminated the need for transformers in some electronic circuits, transformers are still found in nearly all electronic devices designed for household ("mains") voltage. Transformers are essential for high-voltage electric power transmission, which makes long-distance transmission economically practical.
A transformer is a device for transferring energy in a system from one circuit to another. It consists of two independent electric circuits linked with a common magnetic circuit. This energy at low voltage may be transformed to energy at high voltage, or vice versa. In the like manner, current of a given value in one circuit may be transformed into current of another value in a different circuit. The winding of transformer connected to the supply circuit is termed as primary winding and these windings of the transformer that are connected to the receiver circuits are called secondary windings.
COST ESTIMATION
Plant Capacity 2 Nos/Day
Land & Building (3145 sq.mt.) Rs. 3.04 Cr
Plant & Machinery Rs. 67.90 Lac
Working Capital for 1 Month Rs. 57.92 Lac
Total Capital Investment Rs. 4.51 Cr
Rate of Return 25%
Break Even Point 61%
CONTENTS
INTRODUCTION
PRINCIPLE OF TRANSFORMER
FIGURE 1: RELATIONSHIP BETWEEN CURRENT, MAGNETIC FIELD STRENGTH AND FLUX
FIGURE 2: TRANSFORMER SCHEMATIC
FIGURE 3: TRANSFORMER CONSTRUCTION
DISTRIBUTION TRANSFORMER
IMPORTANT FEATURES
PROPERTIES
IMPEDANCE OF DISTRIBUTION TRANSFORMER:
COOLING OF DISTRIBUTION TRANSFORMER:
CLASSIFICATION
PRIMARY
SECONDARY
TYPES
TYPE OF INSULATION
NUMBER OF PHASES
VOLTAGE LEVEL
LIQUID IMMERSED TRANSFORMERS
DRY TYPE TRANSFORMERS
COMPARISON - DISTRIBUTION TRANSFORMER & POWER TRANSFORMER
VOLTAGE LEVEL
TRANSFORMER SIZE:
LOADING OF TRANSFORMER:
EFFICIENCY
BASIC DESIGN/CONSTRUCTION
OUTER PARTS OF TRANSFORMER
YOKE
BUCHHOLZ RELAY
CONSERVATOR TANK
OIL LEVEL INDICATOR
BREATHER
WINDING TEMPERATURE INDICATOR
COOLING FANS/RADIATOR
SYSTEM GROUND TERMINAL
DRAIN VALVE
INNER PARTS OF TRANSFORMER
CORE
PRIMARY WINDING (HV-WINDING)
SECONDARY WINDING (LV-WINDING)
WINDINGS
TRANSFORMER OIL
USES/APPLICATIONS
BIS SPECIFICATION
MANUFACTURING PROCESS STEPS
MANUFACTURING BROADLY COVERS THE FOLLOWING PROCESSES:
COIL WINDING
HIGH VOLTAGE COIL
LOW VOLTAGE COIL
CORE ASSEMBLY
CORE-COIL ASSEMBLY
TANK FORMATION
PAINTING
BOX-UP OR TANKING
FINAL TESTING
ROUTINE TEST
INSULATION RESISTANCE TEST
TEST PURPOSE
TEST INSTRUMENTS
TEST PROCEDURE
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
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 USING CT, PT)
SHORT CIRCUIT TEST (WITHOUT CT)
SHORT CIRCUIT TEST (WITH CT)
ACCEPTANCE CRITERIA
TEST CAN DETECT
OPEN CIRCUIT/NO LOAD TEST
TEST PURPOSE
TEST PROCEDURE
TEST CAUTION
ACCEPTANCE CRITERIA
CONTINUITY TEST
PURPOSE OF TEST
TEST INSTRUMENTS
TEST PROCEDURE
TEST CAN DETECT
MAGNETIC CURRENT TEST
TEST PURPOSE
TEST INSTRUMENT
TEST CIRCUIT DIAGRAM
MAGNETIC CURRENT TEST
TEST PROCEDURE
TEST CAUTION
MAGNETIC BALANCE TEST
TEST PURPOSE
TEST INSTRUMENT
TEST CIRCUIT DIAGRAM
TEST PROCEDURE
HIGH VOLTAGE TESTS ON HV & LV WINDING
PURPOSE
TEST INSTRUMENT
TEST CIRCUIT DIAGRAM
LV HIGH VOLTAGE TEST
TEST PROCEDURE
DIALECTICAL TEST
TEST PURPOSE
TEST INSTRUMENTS
TEST PROCEDURE
METHOD NO 1 (SEPARATE SOURCE VOLTAGE WITHSTAND TEST)
DIELECTRIC TEST (SEPARATE 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
TEMPERATURE RISE TEST OF TRANSFORMER
FINISHING & DISPATCH
PROCESS FLOW
MARKET OVERVIEW
GROWTH DRIVERS
CHALLENGES
INDIA POWER & DISTRIBUTION TRANSFORMER MARKET SEGMENTATION
KEY COMPANIES DOMINATING THE MARKET
MANUFACTURERS/SUPPLIERS
MANUFACTURING COMPANIES/SUPPLIERS
SUPPLIERS OF RAW MATERIALS
SUPPLIERS OF HOT ROLLED SHEETS
M.S CHANNELS AND ANGLES
M.S. FLAT
M.S. PLATE
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 & MACHINERIES
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
SHEARING MACHINE
WELDING MACHINE
AIR COMPRESSORS
MATERIAL HANDLING EQUIPMENTS
SUPPLIERS OF PAINTING EQUIPMENTS
FIRE FIGHTING EQUIPMENTS
SUPPLIERS OF EOT CRANE
AIR POLLUTION CONTROL EQUIPMENTS
PLATEFARM WEIGHING MACHINE
SHOT BLASTING MACHINE
ENGINEERING DESIGN CONSIDERATIONS
ETP/WTP FACILITY
SEWAGE AND WASTE WATER EFFLUENT FACILITY
PRELIMINARY PLAN
PRINCIPLES OF PLANT LAYOUT
MAJOR PROVISIONS IN ROAD PLANNING FOR MULTIPURPOSE SERVICE ARE:
PLANT LOCATION FACTORS
PRIMARY FACTORS
RAW-MATERIAL SUPPLY:
MARKETS:
POWER AND FUEL SUPPLY:
WATER SUPPLY:
CLIMATE:
TRANSPORTATION:
WASTE DISPOSAL:
LABOR:
REGULATORY LAWS:
TAXES:
SITE CHARACTERISTICS:
COMMUNITY FACTORS:
FLOOD AND FIRE CONTROL:
HEALTH SAFETY AND ENVIRONMENT
ANTICIPATED ENVIRONMENTAL IMPACTS
CONSTRUCTION PHASE
OPERATION PHASE
MITIGATION MEASURES (PROPOSED)
HSE REQUIREMENT
PROPOSED IMPLEMENTATION SCHEDULE
PROJECT FINANCIALS
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)
