The subject of Electric Generators ("Synchronous Generators" and" Variable Speed Generators" as in book here) attracted formidable R&D effort, both in Academia and in various industries in the last decade. To the point that "Electric generators design, testing and control" - the subject of present book set, may constitute a new senior or graduate Course in Universities with electric power programs and a practical guide for young professionals in industry. In the last 10 years design and control of electric generators for applications in energy conversion, through transport electrification, e-buildings, industrial processes, auxiliary power sources, inspired a rich body of new knowledge. By now, only the wind energy industry has more than 1000 GW of installed power (in 2025). In view of this progress, we decided (after 10 years) to come with a new (third) edition of this two-set book that:

• Keeps the structure of the second edition to avoid confusion to long-term users.
• Keeps and adds to the style with more numerical work-out examples of practical interest, together with more case studies to inspire the new R&D reader.
• Includes additional (though minor) needed text and number corrections.
• Adds quite a few new paragraphs, in most existing Chapters, especially as case studies of design or control of new (recent) electric generator systems of hot industrial interest.