Table of Contents
What is dielectric strength of transformer oil?
| Material Dielectric Strength | |
|---|---|
| Perfect Vacuum | 1×1012 MV/m |
| Transformer Oil | 24 MV/m |
| HDPE Insulator | 20 MV/m |
| Silicon Insulator | 20 MV/m |
What properties should a good transformer oil possess?
Synthetic transformer oil like chlorinated diphenyl has excellent properties like chemical stability, non-oxidizing, good dielectric strength, moisture repellant, reduced risk due to fire and explosion.
Which factors reduces the breakdown strength of transformer oil?
As the insulating medium of power transformers, oil-impregnated paper (OIP) degrades under interaction with heat, moisture, oxygen, and acids [2,3]. Among those aging factors, heat is the main cause of insulation aging, and thus reduces its mechanical strength and electrical performance.
What should be BDV of transformer oil?
A typical value of BDV Test result for 220 / 6.6 kV Transformer oil is 65 kV and moisture content should be less than 10 ppm. BDV is an important and popular test of transformer oil, as it is the primary indicator of the health of oil and it can be easily carried out at the site.
What are the qualities of good transformer oil?
What is breakdown strength of oil in transformer?
Proper record of breakdown strength of oil will be a good guide to the state of oil as oil with moisture and impurities has low breakdown voltage. The presence of moisture in a transformer is very harmful. It decreases the dielectric strength of oil and other insulating material such as winding insulation, paper, etc. significantly.
What is the minimum breakdown voltage for a transformer?
For example, for new trans formers above 170 kV the recommended lower limit is 60 kV, whereas breakdown voltages below 50 kV indicate a need for oil reconditioning [2]. In order to vary the moisture level of the oil, saturated nitrogen flow was fed into the oil under constant stirring.
What is the treatment of transformer oil?
If the breakdown strength of transformer oil is lower than the specified value the oil should be treated in a filtration plant. A plant which provides for heating filtration and drying under vacuum is to be preferred as filtering alone cannot remove moisture and dissolved air.
How to check the quality of transformer oil?
1 Transformer Oil Dielectric Strength Test Procedure. The gap of the electrodes is first checked with a gauge. 2 Moisture Test of Transformer Oil. The presence of moisture in a transformer is very harmful. 3 Neutralization Test of Transformer Oil. Acids are formed in a transformer during operation. 4 Filtration of Transformer Oil.