Power And Distribution Transformer Principle, Operation, And Maintenance

Instructor by: Bambang Harjoko 17-19  Juni 2014, New Shapir Hotel, Yogyakarta 10– 12 Juni 2014, New Shapir Hotel, Yogyakarta DESCRIPTION Transformers are major components of electrical power systems. This course combines theoretical and practical aspects of transformer design, operation, maintenance and troubleshooting. The course emphasizes the importance of the magnetic properties of the core design on the transformer’s operational performance and electrical properties. It addresses economic trade-offs of transformers in real-world applications. HOW YOU CAN BENEFIT FROM THIS TRAINING To provide a comprehensive understanding of principles, selection, testing and commissioning, protection, maintenance and troubleshooting of distribution, and power transformers WHO SHOULD ATTEND THIS TRAINING Electrical engineering professionals who need to update their knowledge, distribution system planners, maintenance managers, and power system consultants. The participants should have a basic understanding of power system operations, but do not necessarily have to be experts. Also, the engineers who are starting their career in the field of power in utilities, industrial or commercial plants and institutional complexes will benefit from this course. TRAINING MATERIAL OUTLINE : A. Basic Transformer Theory

1. Currents and magnetic fields
2. Air core transformer
3. The magnetic circuit
4. The B-H curve
5. Hysteresis, and eddy current losses
6. Iron or steel core transformer
7. Equivalent circuit of an iron core transformer
8. The practical transformer
9. Magnetizing currents and harmonics
10. Voltage considerations
11. Thermal considerations

B. Power Transformers

1. Rating and classifications
2. Short circuit duty
3. Efficiency and losses
4. Construction
5. Accessory equipment
6. Inrush current
7. Modern and future developments

C. Distribution Transformers

1. Construction
2. General transformer design
3. Transformer locations
4. Transformer losses
5. Performance
6. Transformer loading
7. Special tests
8. Protection
9. Economic application

D. Underground Distribution Transformers

1. Vault installations
2. Surface operable installations
3. Pad mounted distribution transformers

E. Dry Type Transformers

1. Dry type transformers

F. Transformer Connections

1. Polarity of single-phase transformers
2. Angular displacement of three-phase transformers
3. Three-phase transformer connections - advantages and disadvantages of the Y-Y connection, the Y-delta and delta-Y connection, the Y-delta grounding bank, zigzag connections, comparisons of economy, three phase banks using single phase transformers, transforming two-phase voltages into three-phase voltages, the scott-connected connection, autotransformers and three-winding transformers
4. Parallelling of transformers

G. Loading Power Transformers

1. Design criteria
2. Nameplate ratings
3. Other thermal characteristics
4. Thermal profiles
5. Temperature profiles
6. Temperature measurements
7. Predicting thermal response
8. Load cyclicality
9. Water in transformers under load
10. Voltage regulation
11. Loading recommendations

H. Auxiliary Equipment

1. Bushings types, standards, design parameters, and testing
2. Oil preservation systems
3. Cooling equipment
4. Temperature and oil level gauges

I. Load Tap Chargers (LTCs)

1. Design and applications of load tap changers
2. Rated characteristics and requirements for load tap changers
3. Selection of load tap changers
4. Maintenance of load tap changers
5. Refurbishment replacement of old LTC types

J. Transformer Selection and Application

1. Most economical transformer for your application

K. Transformer Protection

1. Fuses and relays
2. Gas relays
3. Differential protection
4. Code requirements

L. Transformer Installation

1. Transformer installation
2. Sample transformer acceptance check list

M. Testing Transformers

1. Standards, and classification of tests
2. Sequence of tests
3. Voltage ratio and proper connections
4. Insulation condition
5. Dielectric withstand
6. Performance characteristics
7. Other tests

N. Maintenance and Troubleshooting

1. Sample operating and maintenance instructions
2. Preventative maintenance and predictive maintenance
3. Gas in oil analysis
4. Water in oil analysis
5. Drying techniques
6. Oil dielectric tests
7. Sample transformer maintenance checklist
8. Problem and failure investigations
9. Problem analysis after severe operating conditions where no failure is involved - failure investigations

O. Power Transformer Equipment Standards and Processes

1. Major standards organizations
2. Process for acceptance of American National Standards
3. Relevant power transformer standards documents

P. Electrical Power System

1. Electric power grid representation and characteristic
2. Type of electric power system configuration
3. Basic calculation in normal condition
4. Load shedding system and load analysis
5. Basic calculation in disturbance condition and disturbance analysis
6. Electrical Power System Monitoring Equipment
7. Interactive discussion and cases study

TRAINING METHOD

• Presentation
• Discussion
• Case Study
• Evaluation

FACILITY

• Training Kit
• Handout
• Certificate
• Lunch + 2 X Coffee Break
• Souvenir