Single-Phase Power Transformer Formed Cores

For many years power and distribution transformer cores were built of hot-rolled laminations assembled into a core structure. When cold-rolled, oriented strip steel was introduced into transformers, new types of distribution transformer cores were developed. These cores were of the wound type and utilized the magnetic properties of oriented steel very efficiently. Recently, a new type of single-phase power transformer core using oriented steel has been developed and put into production. A description of the design, manufacture, and characteristics of this new core is given. Power transformers with this type of core built by the General Electric Company are designated Spirakore transformers.