There are the physical and chemical properties which transformer oil is easily deteriorated by the solid particles in oil

especially the influences of metal particles on the insulation performance of oil is more significant. Based on the ISO4406 standard

we prepared 24 groups of oil samples with different particle sizes and different pollution degree of Cu

Fe

and SiO

2

by a uniform design method. Moreover

we obtained the influence law of different component and particle content on the breakdown voltage of oil according to the test performance of breakdown voltage. According to the test data

we established a mathematical model of support vector machine between particles with different particle size

particle content and breakdown voltage of oil samples. The results show that the determination coefficient is 0.9551 and the root mean

square error is 0.181×10

-2

of the validation set using the model; With the increase of the content of Cu

Fe

and SiO

2

particles

the breakdown voltage of oil is decreased; The contamination of particles in the range of 5～25 μm has a significant influence on the breakdown voltage of oil

and the bigger the particle diameter is

the greater the breakdown voltage of oil will be.