Detailed Project Report (DPR) on Distribution Transformer

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)