Solid cast transformers

The author provides an overview of the available types of solid cast transformers and compares the advantages and disadvantages of solid cast transformers with those of alternatives. Specifically, a comparison between different solid cast construction techniques is made in the following areas: available techniques; high voltage coils; low voltage coils; and mechanical, electrical, thermal strength, and flame test results. Also, comparisons are made between solid cast transformers and other dry-type and liquid-filled transformers. It is concluded that solid cast transformers do not present potential environmental problems, have proven to be self-extinguishing in flammability tests, can match the basic insulation levels (BILs) of liquid-filled transformers, have higher short-circuit strength, require very little maintenance, and have a very competitive total installed cost.<>