Power Transformer Failure Analysis & Troubleshooting

Introduction

Electricity is high-grade energy. Working in the electrical substations and generating stations needs to be able to deal with the power transformers. All staff managers, administrators, engineers, or technicians need to understand the power transformers' rules and their applications and also learn the requirements of power maintenance, testing, and transformer failure analysis and troubleshooting and be able to understand the protection system of power transformers. The Electricity Companies have to supply electricity to the consumers at the lowest possible cost commensurate with safety. Power Transformers represent a major capital asset for electricity suppliers. While in service power Transformers must be maintained and monitored in order to anticipate faults and possibly avert any failure. Faults in Power Transformers can occur at any time, and the causes are many and varied. When faults do occur they generally cause loss of supply to customers and loss of revenue for suppliers so it is imperative that the fault location process is efficient and accurate to minimize excavation time, which results in results in reducing the inconvenience to all concerned. For fault locating to be efficient and accurate technical staff needs to have expert knowledge accompanied by experience in order to attained service reliability. This course is designed to ensure that those responsible for the diagnosis, operation, testing, maintenance, and monitoring of power transformers understand the technical issues involved and comply with relevant specifications and requirements. This course is designed to raise the level of electrical engineers dealing with power transformer to provide specific guidance to those who must implement and follow the associated procedures.

Objectives

By the end of the training, participants will be able to:

• Develop a thorough understanding of electrical power transformer rules and their application

• Understand individual responsibilities for power transformers in substations

• Learn the detailed procedures for testing of power transformers standards

• Understand the power transformer failure analysis & troubleshooting

• Learn requirements for the maintenance of power & distribution transformers

• Develop an understanding of the role of switchgear and associated protection in transformers

• Identify key issues for the improvement of their company’s power transformers’ operation

Training Methodology

This is an interactive course. There will be open question and answer sessions, regular group exercises and activities, videos, case studies, and presentations on best practice. Participants will have the opportunity to share with the facilitator and other participants on what works well and not swell for them, as well as work on issues from their own organizations. The online course is conducted online using MS-Teams/ClickMeeting.

Who Should Attend?

This course is intended for Engineers and Technicians from Electrical Power Utilities Companies, Manufactures, and Distributors of Power Transformers, Engineering professionals in Petrochemical Companies, and Commercial Buildings. Participants need no specific requirements other than a basic understanding of Electricity and Magnetism and knowledge of nature and operation of Power supply and distribution system.

Course Outline

Day 1: Introduction of Power Transformers

• Historical survey of Transformer Development and Applications

• Transformer Design and Construction Defining Transformer Life Expectancy The Insulation System

• Life Time of Transformer

• Transformer’s Oil

Routine Tests

• Measurement of Voltage Ratio and Check of Vector Relationship

• Measuring of Winding Resistance

• Measuring of Impedance Voltage and Load Loss

• Measuring of No-Load Loss and Current

• Dielectric Tests 2.6 Separate- Source Voltage withstand Test

• Induced over - Voltage withstand Test

• Partial Discharge Measurement

• Test on On - Load Tap Changer

Day 2: Special Tests

• Temperature Rise Test

• Measurement of Zero Sequence Impedance

• Measurement of Voltage & Current Harmonics

• Measurement of Insulation Resistance Measurement of Capacitance and (tan)

• Lightning Impulse Test

• Switching impedance Test

• Measurement of Acoustic Sound Level​

Day 3: Oil Immersed Transformers

• Application Field

• Categories of Equipment

• Transformer Classification

• Specification for uninhabited Insulation Mineral Oil

• Main Standards used for Routine Tests

• Recommended limits for unused mineral insulating oils field in new Power Transformer

• Oil Functions

• Dissolved Gas Analysis (DGA)

• Incipient Fault Detection in Oil Immersed Transformer and Faults Types​

Day 4: Measurements of Insulation Resistance

• Introduction of Insulation Resistance Measurements

• Two Windings Measurements

• Three Windings Measurements

• Measurement Analysis

• Measurement Instruments

Measurements of Voltage Ration

• Introduction

• Measuring Circuit

• Measurements Analysis

• Measurements Instruments

• Capacitance & Power Factor (C & (tan)

• Introduction

• Bushing Capacitance

• Power Factor Measurements

• Tap Insulation Capacitance

• Hot Collar Technique

• Transformer Capacitance

• Two Windings Transformer Test procedures

• Three Windings Transformer Test Procedures

• General Test Procedures for Windings

• Losses and Cos 0 variation with Test Voltage

• Test of Oil Insulation Power Factor

• Transformer Exciting Current Measurements

Day 5: Partial Discharge Techniques

• What is Partial Discharge?

• Why Test for Partial Discharge?

• Occurrence of Discharge

• Physical Background of Partial Discharge

• Type of Partial Discharge 8.7 Magnitude of Discharge

• Characteristic of discharge Patterns

• Partial Discharge Test Facility

• Partial discharge with Induced Voltage

• Actual Detection Circuits

• How to calibrate the Partial Discharge System?

• How to measure Partial Discharge?

• Partial Discharge Methods Available

• On-Site Partial Discharge Measurements