Rising energy and transmission economy requirements have produced a demand for increasingly larger EHV transformer units capable of meeting the very high operational security standards associated with modern interconnected EHV networks in which the entire energy output is combined.

In addition to appropriate design and material processing methods, efficient drying, degassing and impregnation process technology is a decisive factor to consider. since it is the one on which optimal utilisation of the excellent properties of paper-oil dielectric system depends. Efficient drying of insulation, therefore, is a vital requirement for transformers.