Characterization of high performance AIN nanoparticle-based transformer oil nanofluids

摘要

Well dispersed aluminium nitride(AlN) nanoparticles were synthesized by two-step ball milling coupled with surface coating. The AlN nanofluids (NFs) were prepared by dispersing as-prepared nanoparticles into transformer oil. The modified NFs is investigated as a new generation of transformer oil. The insulating properties have been investigated firstly. In the case of our AlN NFs with 0.079% <; Φ <; 0.159% (Φ means the volume concentration of AlN nanoparticles in the transformer oil), the positive lightning impulse breakdown voltage and partial discharge inception voltage (PDIV) increased around 50% and 20% compared to those of the transformer oil while alternating current (AC) breakdown voltage decreased around 20-30%. However, it can still meet the demand of the standard below 330 kV. The results show that AlN NFs have a concentration dependence of AlN nanoparticles. The amount of large particles increases with the increasing concentration of AlN nanoparticles while trap density of NFs increases first and then decreases, both of which have an opposite effect on the dielectric strength. Furthermore, the experimental results showed that the thermal conductivity is increased by 3-7% because of the addition of AlN nanoparticles.