Optimizing Antioxidant Synergy for the Restoration of Aged FR3 Transformer Fluid

This study focuses on the restoration of aged FR3 transformer fluid by optimizing antioxidant formulations to enhance its dielectric and physicochemical properties. A composite antioxidant approach, incorporating tertiary butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), alpha-tocopherol, and citric acid, is employed to improve fluid performance. The efficacy of various antioxidant combinations is evaluated based on key parameters, including breakdown voltage, acidity, flash point, fire point, and dielectric dissipation factor. Response Surface Methodology (RSM) is utilized to optimize the antioxidant blend, while ANOVA (Analysis of Variance) assesses the statistical significance of the developed models. The optimized antioxidant combination improved breakdown voltage by 45.18% (R² = 0.9529), reduced acidity by 59.09% (R² = 0.9763), and enhanced flash by (37.17%) and fire points by 30.85% (R² = 0.9454 and 0.8022, respectively). Dielectric dissipation factor also showed strong improvement (24.32%) (R² = 0.9534). The high R², adjusted R², and adequate precision values indicate robust model reliability and predictive capability. While breakdown voltage exhibited acceptable lack of fit (p = 0.0255), other responses showed non-significant lack of fit, confirming model adequacy. These findings highlight the method’s effectiveness, synergistic antioxidant effects, and potential for sustainable transformer maintenance.