Analyzing the Impact of TiO₂ Nanoparticles in Transformer Oil-Based Nanofluids Through Dissolved Gas Analysis

Nanofluids based on transformer oil have emerged as promising candidates for improving insulation performance in high-voltage equipment. This study investigates the influence of TiO2 nanoparticles on the dielectric strength and dissolved gas behavior of transformer oil at concentrations of 0.01–0.1%. Breakdown Voltage (BDV) testing shows a maximum improvement of approximately 9.6% at 0.05% TiO2, confirming the beneficial role of nanoparticles in suppressing streamer propagation at optimal loading. Dissolved Gas Analysis (DGA) reveals concentration-dependent variations in gas evolution, with hydrogen and hydrocarbon gases increasing near the optimal concentration and declining at higher loading due to probable nanoparticle agglomeration. Comparative interpretation using Doernenburg, Rogers, IEC ratio methods, and Duval graphical techniques indicates that nanoparticle addition can shift diagnostic classification toward thermal or partial discharge regions despite the absence of actual fault conditions. These findings demonstrate that TiO2 nanofluids exhibit a nonlinear dielectric–chemical response and may influence conventional transformer diagnostic interpretation. The study provides a baseline reference for understanding dissolved gas behavior in nano-modified insulating oils and highlights the need to consider nanoparticle-induced gas patterns when applying standard DGA frameworks to advanced transformer insulating fluids.