- Evaluation of Transformer Solid Insulation
- Furaldehyde in Oil
- Gas in Oil Analysis
- Oil Quality Testing
- Analysis of SF6 Gas
Direct Evaluation of Transformer Solid Insulation
The mechanical properties of insulating paper can be established by direct measurement of its tensile strength or degree of polymerization (DP). These properties are used to evaluate the end of reliable life of paper insulation. It is generally suggested that DP values of 150-250 represent the lower limits for end-of-life criteria for paper insulation; for values below 150, the paper is without mechanical strength.
Furaldehyde in Oil
As paper degrades, a number of specific furanic compounds are produced and dissolve in the oil. Of these, 2-furaldehyde is prominent, and its concentration has been related to the strength of paper as measured by its degree of polymerization (DP). Measurement of 2-furaldehyde in oil provides a convenient, non-invasive method to assess the condition of the paper insulation.
Gas in Oil Analysis
Transformers are vital components in both the transmission and distribution of electrical power. The early detection of incipient faults in transformers reduces costly unplanned outages.
Oil Quality Testing
Electrical insulating oil is the “life blood” of power transformers. The condition of the oil greatly affects the performance and the service life of transformers and other oil-filled electrical apparatus. A combination of electrical, physical and chemical tests are performed to measure changes in the electrical properties, extent of contamination and the degree of deterioration in the insulating oil. The results are used to establish preventative maintenance procedures to avoid costly shut downs, avoid premature equipment failure and to extend the service life of the equipment.
Analysis of SF6 Gas
The excellent dielectric and arc quenching properties of SF6 make it an ideal insulating gas for medium and high voltage applications. Detailed knowledge of the nature and amounts of SF6 contaminants and decomposition products can provide a useful diagnostic technique for in-service equipment. Such information is also essential to protect the health of maintenance personnel when handling SF6 gas and to assist with disposal or recycling of end of life equipment.