Solid Dielectrics

A wide range of different materials are used as solid dielectrics in high voltage plant. Although much use has been made of paper and oil as insulation, the tendency is now to move towards synthetic polymers. As a result, understanding the effects of temperature, mechanical loadings and electrical stresses on polymeric insulation is technologically important and presents numerous scientific challenges.

• Injection of charge into polymers results in energy transfer, chemical changes and light emission. Correlating material properties, electrical characteristics and electroluminescence is important in understanding the earliest stages of breakdown.
• The growth of tree-like structures is a common mode of failure; our recent Raman studies of these are providing unique insights into their formation.
• Polymers are complex systems and well characterized samples are essential in understanding failure processes. We therefore routinely analyze samples using electron microscopy, spectroscopic techniques, thermal analysis etc both to characterize existing samples and to design optimal materials for future work.

Ongoing projects include the electrical, chemical and structural characterization of electrical trees, electroluminescence studies, structure/property relationships in polymers and nanocomposites.

Projects