Motors & Drives Information

Electric Drives and Their Controls: R. M. CROWDER (Oxford University Press, 1998, 238 pp., L22.50 paperback)

This informative book has its origins in the machine tool industry and seeks to present a wide range of factual material which will provide the undergraduate with a thorough background in the multi-disciplinary field of controlled drives for manufacturing industry.

The text appears most suitable for a general course from second year to fourth year, depending on prior education. The student would be expected to have covered the basics of electronic circuits, digital electronics, simple mechanics and motors. There is modest academic depth in the book. The student will not find a mathematically rigorous development of either electrical machine theory or control systems here, though a number of equations are used to describe various processes. As these equations are often stated rather than derived, it would have been useful for more extensive references to have been given, in order that the student could find context, derivation and assumptions underlying each piece of theory; it is unlikely that there would be a complementary course to provide support for every area covered. The book does provide a limited bibliography but at the end, rather than in each chapter.

The material in the book is logically presented within the constraints of the various facets of the topic. After an introduction to set the scene, the selection and sizing of drive hardware is dealt with. A chapter on velocity and position transducers is followed by chapters on motors and their controllers brushed D, brushless D, a.c. induction and stepper. The final chapter considers control schemes (servo systems, motion controllers and programmable logic controllers). Powder semiconductors are covered by an appendix. Considering the author's experience and expertise in this field, it seems a pity that one or more case studies of system design have not been included.

# posted by Medical Information : 5:17 AM