Biorefinery-based evaluation of Karanja oil and Mahua oil as sustainable alternatives for transformer insulation

The need to mitigate environmental impacts in the power sector has driven research into sustainable bio-liquid insulation alternatives for transformers. This study focuses on developing and rigorously evaluating biodegradable electro-insulating liquids, specifically Karanja oil and Mahua oil, as eco-friendly substitutes for conventional petroleum-based transformer oil. To reduce viscosity, a decane paraffin solvent was added. Comprehensive analyses of the physicochemical properties, AC and impulse breakdown characteristics under various conditions, statistical AC and impulse breakdown voltage, partial discharge behavior, and Weibull distribution survival analysis were conducted. Results show that additive-included Karanja oil and Mahua oil have promising potential as sustainable bio-liquid insulation alternatives. Both oils exhibit good physicochemical characteristics and excellent dielectric breakdown under AC and impulse exposure. Superior performance in survival and hazard in adverse conditions was supported by partial discharge inception voltage and Weibull statistical analysis with Karanja oil and Mahua oil. While some limitations were identified, they can be addressed with appropriate mitigation approaches. This methodical development and analysis underscore the environmental compatibility of these oils without compromising performance metrics. The findings establish Karanja oil and Mahua oil as promising, efficient alternatives for sustainable power transformer insulation, expanding viable options for the power industry.