Comparative Dielectric Performance Analysis of Vegetable-Based Oils and Mineral Oil under Thermal-Oxidative Stress
IEEE Transactions on Dielectrics and Electrical Insulation, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1109/tdei.2026.3737091
- Dergi Adı: IEEE Transactions on Dielectrics and Electrical Insulation
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Compendex, INSPEC, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Breakdown voltage, dissipation factor, insulation oils, partial discharge
- Kırklareli Üniversitesi Adresli: Evet
Özet
Sustainable and biodegradable natural ester liquids are increasingly considered viable alternatives to mineral oil in power system equipment. This study presents a comparative evaluation of the dielectric performance of three vegetable-based insulating oils (sunflower, canola, and cotton) and a conventional mineral oil under thermal-oxidative stress. The dielectric response is characterized through breakdown voltage (BDV), frequency-and voltage-dependent dielectric dissipation factor (DF), dielectric losses (DL), resistivity and relative permittivity, as well as partial discharge (PD) measurements. Experimental results indicate that thermal stress significantly increases the BDV of all samples. While sunflower and mineral oils maintain stable DF values, cotton and canola oils exhibit significant increases in dielectric losses, attributed to the formation of polar oxidation byproducts. Furthermore, partial discharge analysis demonstrates that the PD inception voltage (PDIV) generally increases after thermal stress. Also, while the PD repetition rate decreases, the discharge magnitude intensifies in vegetable oils, indicating a transition to less frequent but more severe discharges. The results highlight that breakdown voltage alone is insufficient for assessing the condition of insulation oils. A comprehensive multi-parameter dielectric characterization is essential to detect early-stage degradation processes under thermal stress.