The book deals with the following aspects of transformer engineering: general principles governing the function of transformers, iron cores, windings, stray losses caused by stray flux, the insulation of transformers, and the structural parts and accessories. This edition includes the latest developments in theory and practice on the basis of the authors' experience in design, manufacturing and testing of large transformers. New developments have been particularly extensive in the fields of new magnetic materials, cooling methods, dielectric strength for overvoltages of different types, and stray-load loss problems, which are presented in the book in detail. The many diagrams in the book can be used directly in the design, manufacture and testing of large transformers. In preparing their text, the authors have aimed to satisfy the demand for a work that summarizes the latest experience in development and design of large power transformers. The book is intended for engineers engaged in the design, manufacture, processing, commissioning and operating of power transformers, as well as for students and R&D personnel.