Nanostructured insulation for high torque density electric propulsion motors

It has been identified in ONR Next Generation Integrated Power System (NGIPS) Roadmap that fundamental research in dielectric insulation research enables payload efficiency and affordable high power density of integrated electric propulsion motors. The objective of this study is to revolutionize electrical insulation in the manufacturing of NGIPS motors for military electric propulsion with game-changing torque density and payload efficiency through the development of nanostructured insulation with significant improvements in both electrical and thermal performance. This paper presents the progress of nanostructured insulation innovation, high field characterization, performance and insulation integrity validation under high voltage, high frequency multi-stresses. The thermal, dielectric and voltage endurance properties of novel nanocomposite insulation based on 2D-nanostructured platelet fillers were investigated. It was demonstrated that nanostructured insulation could offer significant improvement over conventional insulation system in electrical, dielectric, thermal and mechanical properties. A Design of Experiment was employed to study the effects of various 2D fillers and their interplay, and more importantly to identify the optimal nanostructured formulation with high thermal conductivity of >0.8 W/mK, low dielectric constant of less than 5, low dissipation factor of less than 3% at 150°C and high breakdown strength of >1000V/mil. Furthermore, disk samples with optimal formulation from Design of Experiment were fabricated for voltage endurance tests in accordance with IEC 60343 standard for evaluation of their long-term endurance life.