As the subject makes use of a number of empirical Formulas in the Design of Different types of Electrical Machines, I think the following Links may be of use.
The First Link gives the evaluation version,free ,but may contain some Possible errors as stated by the authors. The second link gives the book available in the market.
1. issuu.com/motordesign/docs/preview_book
In this book two of the most experienced authors in the field have come together to present a practical guide to the design of electric machines using the SPEED and Motor-cad for the use of different types of Electrical Motors including Thermal aspects also.
2. http://www.motor-design.com/textbooks.php
Electric Machine Design using SPEED and Motor-CAD
by Prof T.J.E. Miller & Dr D.A. Staton
In this book two of the most experienced authors in the field have come together to present a practical guide to the design of electric machines using the SPEED and Motor-CAD software packages. These were written to work together; one for the electromagnetic and the other for the thermal aspects of motor design.
Ten different machine types are introduced in the book, starting in each case from a simple specification and proceeding through to a credible prototype. Rules of thumb and basic engineering principles are used throughout to guide and inform the design process, and reference is made to the extensive documentation of both SPEED and Motor-CAD for a deeper theoretical understanding.