The participant should be able to:

1. Explain the basic operation of a transformer as a main component in any electrical

network.

2. Determine different shapes and designs of transformers.
3. Discuss turns ratios and calculate terminal voltage and current.
4. Discuss terminal markings and various single-phase and three-phase wiring schemes.

(WYE vs DELTA).

5. Discuss the electrical testing performed on transformers such as insulation resistance

testing, excitation, and power factor testing.

6. Discuss the various tests performed on insulating oil.
7. Understand Safe and proper maintenance and troubleshooting procedures on power

transformers.

8. Learn practical new solutions for specifying, operating, and maintaining power

transformers in a utility or plant environment

9. Avoid costly errors from specifying the wrong transformer for your application and

from failing to recognize the importance of specifying the right core design

10. Examine the possibilities of maximizing the efficiency and economic performance of

your transformer fleet

11. Determine precise transformer specifications for every application
12. Become familiar with what makes a power transformer tick
13. Gain knowledge of both the underlying principles and practical applications of power transformers in today's competitive world

This course aims to provide an understanding of the fundamentals and constructional features of Power

Transformers with particular reference to the design, testing, operation, and maintenance of transformers

in power systems. The course also highlights the necessary safe procedures relating to Transformer

Isolations, Energizing, and related circuitry. Special emphasis is also placed on the Testing and

maintenance of transformers. Upon completion of this course,

Engineers and technicians from the electricity supply industry - Engineering professionals from companies

Manufacturing, importing, and distributing Power and Distribution Transformers – Engineers and technical

personnel in power utilities, co-generation operators, petrochemical plants, and service managers of

buildings and hospitals. Participants need no specific requirements other than a basic understanding of

electricity and magnetism and circuit theory and general knowledge of the nature and operation of Power Transformers

This interactive Training will be highly interactive, with opportunities to advance your opinions and ideas, and will include:

• Pre-test and pro-test
• Variety of learning methods
• Lectures
• Case studies and self-questionnaires
• Small group work
• Discussion
• Presentation

INTRODUCTION AND BASICS

Introduction

Magnetic field

Magnetic and electric fields

Electromagnetism

Electromagnetic induction

Generating electrical current

Three-phase system

Worldwide AC voltages and frequencies

Per-unit values

TRANSFORMER THEORY

Purpose

Scope

Types of transformers

Transformer applications

Magnetic circuit

Magnetic and electric circuits of a transformer

Winding, current and voltage ratios

Laws of transformer

Principle of operation of a transformer

Reflected impedance

Transformer equivalent circuit

Transformer losses

Efficiency

Why is transformer efficiency usually high?

Regulation

Transformer's voltage per turns

Significance of volts per hertz

TRANSFORMER CONSTRUCTION

Introduction

Core material

Core configurations

Transformer core types

Transformer windings

BushingsTank

Transformer tank fittings

POWER TRANSFORMER COOLING AND SEALING SYSTEMS

Introduction

Cooling arrangement

ONAN type cooling

ONAF type cooling

OFAF type cooling

OFWF type cooling

Gas insulated transformer

Comparison

Temperature gauges

Oil level gauge

Thermal time constant of power transformer

Power transformer sealing systems

Effect of oil expansion

Silica gel breather and moisture

TRANSFORMER PERFORMANCE

Nameplate data

Transformer parameters

Three-phase transformer

Auto-transformer

Transformer tap changer

Parallel operation

Maximum efficiency

Dry type transformer

Transformer noise

Permissible loading of oil-immersed transformers

Special transformers

TRANSFORMER POWER FACTOR AND HARMONICS

Introduction

Causes of low power factors

Known loads power factors

Annual power factor penalty

Unfavourable effects of low power factor loads

Capacitor price simple payback

Power factor improvement

Power factor improvement for power transformer

Transformer reactance

Capacitor sizes required to compensate the no-load reactive power of transformers

Voltage rise

Harmonics

WaveformUseful parameters

Sources of harmonics

Problems created by harmonics

Third harmonics generate large neutral currents

Third harmonic filter

Installation of THF in different networks

Active filter (power quality filter)

K-rated transformer

TRANSFORMERS PROTECTION

Transformer faults

Differential relays

Biased differential relays

Restricted earth fault protection

Over current protection

Overload protection

Gas-operated (Buchholz) relay

Sudden pressure relay

The internal fault detector

Explosion vents

Temperature indicator

Tank earth protection

OIL TESTING

Definitions

Functions of transformer oil

Transformer oil properties

Transformer oil standards

Hydrocarbon compounds in transformer oil

Moisture problems

Factors affecting transformer oil properties

o Cellulose degradation

o Oil dielectric strength test

o Relative water content test

o Physical & chemical tests (polar characteristics of oil)

o Dielectric loss angle & resistivity test (power factor test)

o Transformer dissolved gas-in-oil analysis (DGA)

o Oil colour test

o Insulating oil sampling procedure

o Oil purification and dehydration

o Yearly insulating oil testing

o Oil aging

Preventive maintenance procedures for transformer oil

TRANSFORMER TESTING

Test dataAbnormal operating conditions of power transformer

Reasons for transformer testing

Transformer performance assurance

Classification of transformer tests

Winding resistance test

Polarity test

Ratiometer test

No-load losses test

Load losses test

Percentage impedance voltage measurement

Leakage reactance measurement

Efficiency test

Winding insulation resistance test

Winding insulation capacitance & dissipation factor (tan δ) test

Sudden short circuit withstand test

Oil pressure test

Temperature rise test

Impulse testing

Transformer arrival: Handling, Inspection and Pre-Commissioning

TRANSFORMER DIAGNOSTICS AND MONITORING

▪ Safety

▪ Visual inspection

▪ Transformer diagnostics

▪ Transformer monitoring

▪ Transformer maintenance management