Critical Wave Forms in Dry Type Transformers

This paper concerns critical wave forms in dry type transformers under transient voltage application. A very general approach has been applied, meaning that many of the results will be applicable to various types of power transformers. The results can be very useful if they are combined with knowledge of the ageing effects of the insulation. Especially fast transients are likely to become a major issue due to fast breakers and power electronics. In order to perform relevant research in transformer insulation with respect to this subject, fundamental knowledge about the transmission and distortion of incoming transients is required. Thus, in this paper it is illustrated how the resulting internal wave forms are affected by different transformer characteristics.