The pros and cons of present transformer insulation thermal classification

Summary form only given. The technology of insulation has accelerated in recent years. The old, time proven insulations have been improved, and new synthetic and natural insulations and composites are frequently appearing. These new insulations add to the difficulty of the designer, in trying to improve his product. His struggles to keep abreast of technological improvements are endless. Present transformer thermal classification is the part of this effort which we will explore in this paper.