TRANSFORMER CONDITION ASSESSMENT LEVEL 3

OVERVIEW
In the electric power supply industry, the role of power transformers has a strategic role. Compare to distribution transformers, power transformers have a different operation condition because on power transformer there are on load tap changer (moving context) and power transformers operate at the end of high voltage transmision lines where lightning strokes hit frequently on transmission lines creating travelling waves which could enter power transformers and create damage. Therefore installing lightning arrester in front of power transformers is very essentials.

OBJECTIVE
On completion of this course, engineers an technicians will have a comprehensive understanding of the principles of transformer maintenance objective, transformer insulation system, capability of transformer against thermal and mechanical stress, transformer monitoring technique for ON and OFF line operation.

CONTENT

1. The role of power transformers
   • Construction and working principles
   • Main parts of power transformers
   • Losses in power transformers
   • Weak points of power transformers
   • Technical specification of power transformers
   • Insulation coordination
2. The objective of maintenance:
   • Development of maintenance methodes
   • What is condition base maintenance
   • Oil transformer construction
3. Paper/cellulose and insulating oil Properties:
   • Chemical
   • Dielectric strength
4. Maximum loading of oil filled transformer:
   • The capability of transformer against non‐sinusoidal load
   • Transformer aging v/s winding temperature
5. Transformer through fault (external short circuit fault)
6. IEE guide for the interpretation of gases generated in oil‐immersed transformer
7. Transformer winding and core deformation derection utilizing SFRA technique
8. On‐line monitoring:
   • Transformer non‐sinusoidal load measurement and interpretation
   • Transformer overall temperature profile/thermal image and interpretation
   • Moisture in oil measurement
9. Off‐line monitoring
   • Measurement of main winding and bushing insulation power factor dissipation
   • Winding and core displacement measurement
10. Operational problems
    • On load tap changer
    • Automatic voltage regulator
    • Requirements for paralel operations
    • Protection of transformers

CERTIFICATION

• Certificate of Attendance (Public Training)