Table 1.
Consumables used in the experiment.
Fig 1.
Experimental flowchart.
Table 2.
Additive combinations.
Table 3.
Additive combinations of titanium dioxide-doped insulating oil.
Fig 2.
Changes in the effect of single additive combinations on the tensile strength of insulating paper with aging.
Fig 3.
Changes in the effect of different additive combinations on the tensile strength of insulating paper with aging.
Fig 4.
Evolution of the tensile strength of insulating paper during aging in titanium dioxide–doped insulating oil under different additive combinations.
The stacked colors represent the contributions of each treatment group: G (TiO₂ only), H (TiO₂ + formic acid), I (TiO₂ + DBDS), and J (TiO₂ + powdered sulfur). Color coding and the expanded legend highlight differences among the chemical environments, enabling clearer comparison of aging behaviors over 30, 60, 90, and 120 days.
Fig 5.
Effect of single additives on breakdown strength of insulating oil.
(a) Variation of breakdown voltage with aging and (b) Weibull distribution.
Fig 6.
Effect of different additive combinations on breakdown strength of insulating oil.
(a) Variation of breakdown voltage with aging and (b) Weibull distribution.
Fig 7.
Breakdown performance of insulating oil under different formic acid–sulfur/DBDS composite additive combinations in TiO₂-modified systems.
(a) Breakdown voltage measured over six repeated tests for each group, with color coding distinguishing the chemical environments: G (TiO₂ only), H (TiO₂ + formic acid), I (TiO₂ + DBDS), and J (TiO₂ + powdered sulfur). The stacked color segments highlight the relative contribution of each treatment to the overall breakdown voltage trend. (b) Corresponding Weibull distribution analysis, showing the characteristic breakdown strengths and reliability levels for each group. The clearer legends and color separations facilitate comparison of how TiO₂ interacts with different aging substances to influence dielectric performance.
Fig 8.
Simulate the effects of aging products in oil-immersed transformers.