Performance of a Bio-based Hydrocarbon type Insulating Liquid

This paper describes an innovative bio-based and low viscosity insulating liquid and is compared to a high-grade mineral insulating oil and ester liquids. Due to its very low kinematic viscosity, this new bio-based hydrocarbon provides improved convective heat transfer in power transformers. Depending on the transformer design, significant temperature reductions of both winding and hot spot can be obtained as shown in a simulation of a 250 MVA transformer. Asset life extension may be achieved by running transformers cooler, or an enabler to uprate transformers while still maintaining them at their designed operating temperature. In addition, this liquid opens new doors to transformer designers in optimization and cost savings. For instance, as shown in the paper, this new liquid allows faster and more complete impregnation of the solid insulation, hence also ensuring there are no trapped voids or air bubbles, which are common causes of partial discharge. Finally, this liquid is readily biodegradable and has excellent oxidation stability, making the insulating liquid ideal for all transformer types including those that are free breathing.