By the end of this course delegates will be able to:

• Refresh your knowledge of the basic theory of transformers
• Understand the principles of operation of the transformer
• Identify the different features of power transformers, distribution transformers and instrument transformers
• Appreciate the principles of transformer design, ratings, windings, core structure and materials, insulation and cooling methods, insulation and lifetime
• Be familiar with construction of the transformer, transformer winding connections
• Recognize the effects of transformer load changes and off-load and on-load tap changers
• Utilize thermal limits and loading guides of transformers
• Analyze transformer failure modes
• Perform transformer maintenance and transformer testing

Engineers and technicians from electricity supply industry - Engineering professionals from companies manufacturing and operating Power and Distribution Transformers Engineers and technical personnel in power utilities, petrochemical plants, service professionals of buildings and hospitals. Participants need no specific requirements other than basic understanding of electricity and magnetism and circuit theory and general knowledge of nature and operation of Power Transformers.

Introduction, General Principles and Classification

• General Classification of Transformers: Transformer Construction, Core-Type, Shell-Type, Dry-type
• Transformers, Oil-filled Transformers, Cooling Techniques
• Transformer Windings, Interconnection of Windings, Advantages and Disadvantages of Principal Connections.
• Tertiary Windings, Autotransformers
• Harmonics in Transformers, Parallel Operation of Transformers, Loadings of Transformers in Parallel,
• Paralleling Requirements, Polarity
• Standards for Transformers, Types and Requirements
• Transformer Tapping’s and Connections
• Ability to withstand Short Circuit, Sound Level
• Case studies and workshop discussion

Transformer Constructional Details

• Transformer Oil, Characteristics, Oil Oxidation, Breakdown Voltage, Water Content, Acidity, Oil Testing, Field
• Oil Testing, Dissolved Gas Analysis, Treatment and Filtering of Oil
• Effect of Oil Expansion, Breathing Action, Buchholz Relay, Explosion Vents
• Instrument Transformers
• Transformers for Industrial Applications: Electro-chemical, Arc and Induction Furnaces, Rectifier Transformers,
• High Voltage Testing Transformers, Precipitator Transformers, Dry Type Transformers
• Construction And Details, Transformer Cooling, Natural Cooling, Forced Cooling

Transformer Features and Thermal Performance

• Thermal performance and Cyclic Rating of Transformers. Temperature indicators and alarms
• Transformer Impedance, Electromagnetic Forces
• Transformer Construction: Cores, Assembly
• Transformer Windings Construction: Coil Types, Disc Coils, Cross-over Coils, Concentric Coils, Sandwich Coils,
• Transpositions
• Transformer Tanks and Radiators, Tank Losses, Paint Treatments
• Transformer Fittings: Lifting Lugs, Undercarriages, Jacking Pads, Tie-Down Lugs, Bleed Pipes, Thermometers

Transformer Operation and Maintenance

• Distribution Voltage Adjustment, Off-Load Tap Changing, On-Load Tap Changing
• Switching of high voltage underground cables supplying Distribution Transformers
• Earthing and Over-Current Protection of Distribution Transformers
• Transformer Maintenance: Oil p reservation , Deterioration of oil, Breathers, Condition Monitoring, Faults in
• Transformers, Tapping’s and Windings
• Advanced Transformer Maintenance
• Guidelines on how to care for your Distribution Transformer
• Transformer Testing
• Transformer Routine Tests, Measurement of winding resistance
• Measurement of voltage ratio
• Measurement of impedance voltage short-circuit impedance and load loss
• Measurement of No-load loss and current
• Insulation resistance, Harmonics testing
• Separate-source power-frequency voltage withstand test
• Induced overvoltage withstand test
• Transformer Type Tests
• Temperature rise test, Lightning impulse test
• Sound level, Special Tests: Transformer Partial Discharge testing
• Accuracy and Interpretation of test results and of test reports

CDGA attendance certificate will be issued to all attendees completing a minimum of 80% of the total course duration.