Preparation of Three Types of Transformer Oil-Based Nanofluids and Comparative Study on the Effect of Nanoparticle Concentrations on Insulating Property of Transformer Oil

Table 1

Basic properties of chosen nanoparticles.

Properties	Transformer oil	Fe3O4	Al2O3	TiO2
Relative permittivity [16, 31]	2.2	80	9.9	114
Conductivity (S/m) [16, 31]	10^−12	10^4-10^5	10^−12	10^−11
Density (g/cm^3)	0.89	5.18	3.97	4.2–4.3
Relaxation time (s)	—	7.47 × 10^−14	42.2	77
Surface modification	—	—	—	—
Material type	Dielectric	Conductor	Insulator	Semiconductor