Experimental investigation of breakdown strength of mineral oil-based nanofluids

Nanofluids were fabricated by employing nanoparticles with different dielectric properties as modifiers to improve the dielectric performance of the mineral oil. Breakdown voltages under AC and lighting impulse stresses were measured to evaluate breakdown strength of these nanofluids. The results indicated that the addition of semiconductive nanoparticles to the base oil can improve the breakdown strength at the optimum concentration of nanoparticle. However, the insulating nanoparticles were unfavorable for the overall dielectric strength of the nanofluids. A possible mechanism was discussed based on the physical properties of the suspended nanoparticles.