Anisotropic properties of graphene nanocomposites for high voltage insulation

Purpose and goal

Objective: Understand the anisotropic electric field grading properties of graphene composite materials based on silicone rubber matrix. Goals: 1. Develop a measurement method to study the anisotropic electric field grading properties of rubber sheets; 2. Test and Benchmark the anisotropic properties of exfoliated graphite and thermally reduced graphene oxide in a silicone rubber matrix against two commercially utilized materials (HTV and BaTiO3); 3. Analyze and understand the measurement results and material properties via finite-element calculations.

Expected results and effects

Results of this project helped in understanding the anisotropic as well as non-linear electric properties of the two different graphene oxide-silicone rubber composites. In addition, electrical testing methods, instrumentation, as well as electrode system for materials’ anisotropic property characterization were developed. These material parameters and testing methods are the basis in design of modern high voltage power apparatuses. Design, prototyping and testing of new types of HVDC bushings with graphene composites as field grading materials are foreseen.

Planned approach and implementation

The developed measurement technique can further be used in different material’s anisotropic and non-linear electrical property characterizations as well as for material selections. The graphene-rubber composite preparation method together with the electrical characterization techniques can be combine in application of materials’ design and optimization. The finite-element material models can further be utilized in large components design as well as verification.