Transformer Design, Construction, Testing and Maintenance Course

Course Overview:

This course offers extensive information on transformer classification, elements, and auxiliary apparatus, and more importantly, how to maintain and conduct test on these equipment.

Attendees will be able to classify and assess power/instrument and distribution transformers, understand nameplate data, and carry out insulation resistance, winding resistance and core excitation tests among others. It also encompasses oil sampling, oil testing, oil drying, oil filling and oil filtering procedures. 

The course provides detailed information on transformer theory, functional construction, methods of cooling a transformer, electrical bushings, tap changers, and transformer site tests. 

It caters to Electrical Engineers and Technologists in the area of design, construction, operation and maintenance of substations, in addition, this course provides insights into transformer fault analysis and maintenance schedules.

Course Objectives:

Upon the successful completion of this course, you will be able to:

• Identify power/instrument and distribution transformer types, components, and auxiliary equipment
• Evaluate transformer configuration for the application
• Interpret nameplate data
• Perform and evaluate the results of insulation resistance, winding resistance, turns ratio, core excitation, and power factor tests of windings, bushings, and liquid insulation
• Perform oil sampling, testing, drying, filling, and filtering

Who Should Attend?

This course is intended for Electrical Engineers those involved in Substation Design, Operation, and Maintenance & Testing. Also, Electrical Technologists who working in Substation Networks are recommended to attend this course.

Course Outlines:

Introduction

• Transformer applications
• Some definitions
• Transformer Types
• Winding, current, and voltage ratio
• Single and multi-phase relationships
• Delta-wye and wye-delta displacements

Theory of Operation

• Three- Phase Transformer Connections
• Voltage and Current Ratings of Transformers
• Transformer Losses and Efficiency

CORE CONSTRUCTION

• Winding Construction

Cooling

• Classifications
• Liquid-filled transformers
• Cooling methods
• The rating according to cooling type

Electrical Bushings

• Purpose of Electrical Bushings
• Types of Bushings Important Design Parameters
• Bushings for Special Applications
• Tests on Bushings Maintenance and Troubleshooting

Dry Type Transformers

• Cooling Classes for Dry-Type Transformers
• Winding Insulation System
• Enclosures
• Operating Conditions
• Limits of Temperature Rise
• Transformer Loading
• Accessories
• Dry-Type Transformer Maintenance

Oil-Filled Transformers

• Transformer Tank
• Top Oil Thermometers
• Winding Temperature Thermometers
• Oil Level Indicators
• Pressure Relief Devices
• Sudden Pressure Relay
• Buchholz Relay
• Testing and Maintenance of High-Voltage Bushings
• Transformer Oil Testing

Transformer Taps and Tap Changers

• Off Circuit Tap Changers
• On Load Tap Changer
• Design of Taps Winding Structure and Configuration of Switches
• Voltage Selection of Each Part of Windings

Transformer Site Test

• Winding Resistances
• Core Insulation Resistance and Inadvertent Core Ground Test
• Voltage Ratio and Proper Connections
• Insulation Condition

Problem and Failure Investigation

• Background Investigation
• Problem Analysis Where No Failure Is Involved
• Failure Investigations
• Special Considerations

Protection Metering & Control System

• Common Transformer Faults
• Yearly Maintenance
• Monthly Maintenance
• Weakly Maintenance