Equipe de Recherche en Systèmes d'Energie Electrique

Gerard Ombick Boyekong; Gabriel Ekemb; Emeric Tchamdjio Nkouetcha; Ghislain Mengata Mengounou;   Adolphe Moukengue Imano

Abstract:

The depletion of the worldwide reserves of petroleum resources combined with the environmental concerns incited researchers and industrials to seek for new appropriate available electroinsulating liquids. The perspective of using mixtures of insulating liquids in power transformers can help to improve the overall performance of these static electrical machines. Natural monoesters represent good candidates for this issue. This paper presents the performance evaluation of eleven proportions of castor and palm kernel oil monoesters blends. Samples were consecutively aged with Nomex-910 papers at 120°C, then 140°C, and finally 150°C for 168 h each. Both the unaged and aged samples undergone dielectric and physicochemical characterization. The dielectric dissipation factor, relative permittivity, acidity, and viscosity increased with aging. However, the electroinsulating and cooling properties were not significantly degraded. Polynomial relationships were proposed to predict these quantities. A simplex lattice design was applied to both new and aged samples to determine the optimal blend formulation. An approximative ratio of 79:21 v/v COME: PKOME was determined. Hence, blending natural monoesters is a significant contribution to the sustainable management of power transformers.

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Industrial Crops and Products
Volume 235, 1 November 2025, 121741

https://doi.org/10.1016/j.indcrop.2025.121741

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