J & P Transformer Book, 13th Edition

2 Design fundamentals

2.1 TYPES OF TRANSFORMERS

There are two basic types of transformers categorised by their winding/core configuration: (a) shell type and (b) core type. The difference is best understood by reference to Fig. 2.1.

Figure 2.1 Transformer types

In a shell-type transformer the flux-return paths of the core are external to and enclose the windings. Figure 2.1(a) shows an example of a three-phase shell-type transformer.

Whilst one large power transformer manufacturer in North America was noted for his use of shell-type designs, core-type designs predominate in the UK and throughout most of the world so that this book will be ...