Programs

COURSE DESCRIPTION:

This course covers the theory, operation, maintenance, and testing of power Transformers and auxiliary equipment. Topics included are transformer fundamentals, transformer ratings, transformer cooling, nitrogen gas systems, and insulation systems. The course concludes with in-depth discussions on transformer testing techniques. This course is applicable to technicians and engineers who need a sound understanding of power transformer operation and maintenance.

Attendance will learn safe and proper maintenance and testing procedures on pad-mounted, power transformers. The course covers transformers used in commercial and industrial power distribution systems, including oil and dry-type units. Larger power transformers used in utility applications are also covered.

Load and no-load tap changer maintenance, ac and dc testing, routine inspections, and oil sampling and testing are covered in detail. Students will learn how to perform routine oil tests and understand how to perform the major tests that are required. A variety of electrical test equipment from various manufacturers will be discussed.

Upon completion of this course, the participant should be able to:

1. Explain the basic operations of a transformer.
2. Discuss turns ratios and calculate terminal voltage and current.
3. Discuss terminal markings and various single-phase wiring schemes. ( WYE or DELTA )
4. Explain how to perform a potential transformer.
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.

OUTLINES:

Transformer Principles.

* Transformers.

* Right-hand rule.

* Magnetic Induction.

* Left-Hand Rule Turns Ratio.

* Transformer Losses.

* Transformer Types.

2- Vector Diagrams.

* Operating Principles.

* Operation without Load.

* Operation with Load.

3- Transformer Classifications:

a- Service Classification.

b- Instrument Transformer.

* Current.

* Potential.

4- Transformer Construction (Construction).

a- Magnetizing Circuits.

b- Losses.

* Hysteresis Loss.

* Eddy- Current Loss.

c- Efficiency.

5- Cooling.

* Air Cooled.

* Oil- Immersed.

* Water- Cooled.

* Forced- Oil Cooling.

* Self-Cooling with Air Blast.

* Temperature Limits.

6- Transformer Loading.

7- Tap Changers.

* No- Load Tap Changer.

* Tap Changing Under Load.

* Phase-Angle Control.

8- Transformer Connections.

* Single Phase Circuits.

* Tow-Phase Circuits.

* Three- Phase Circuits.

9- Transformer Maintenance.

* Insulation Testing.

* High Potential Testing.

* Turns Ratio Testing.

* Polarity Testing.

* Power Factor.

* Excitation Current.

* DC Winding Resistance.

* Polarization Recovery.

* Insulating Fluid Dielectric.

* Dissolved Gas Analysis.

10- Transformers and Relaying

* Transformer Faults

* Differential Relaying

* External Faults

* Internal Faults

Target Audience:

Engineers and Technicians