Cellulose based material for electrical insulation
Ph D Student: Rebecca Hollertz
Cellulose is used as insulation material in oil-filled high-voltage transformers. The pressboard from wood pulp used in the transformers is completely impregnated with oil to extract air and to form a composite material with excellent dielectric properties. Electrical performance and reliability of apparatus are highly impacted by the design and choice of the insulation material. Several deteriorating electrical phenomena that occur may eventually lead to electrical breakdown of the insulation material and failure of the transformer. It is highly desirable to find means to prevent the inception of such phenomena and to limit their deteriorating capacity aiming at improved electrical breakdown strength. To this end it is important to have a profound understanding of the fundamental dielectric properties of the cellulosic material and the factors influencing the propagation of discharges at the surfaces and through the material.
This project is aimed to deliver (i) highly valuable scientific/ technological data and knowledge to serve the development of new insulation models and prototypes, (ii) significant input to material, component and system designer and producers for their further development, (iii) highly relevant data for the development of diagnosis tools to prevent failure mode. These results will pave the way for the development of new generation of insulation materials that confer higher reliability and increased design flexibility in electrical apparatus.