Anyone who has studied electromagnetism will have covered the basic principles of electrical motors, generators, and transformers. There is a huge gap, however, between simple moving loops in magnetic fields and the complexities of the electrical equipment which permeates modern life. Wildi's Electrical Machines, Drives, and Power Systems is an introductory textbook aimed at engineering students who are not necessarily specialising in power engineering, making it fairly broadly accessible.

The necessary physics and circuit theory are quickly recapitulated in part one. No calculus is required, nor any knowledge of Maxwell's equations: indeed phasor addition (simple vector algebra) is the most difficult concept and numerical calculations are always preferred to symbolic treatment. In places I found this avoidance of mathematics a little frustrating. Sometimes it just seems clumsy or awkward, but in other places I suspect some more mathematics would have allowed important insights, even without Maxwell's equations and full-blooded Fourier transforms.

In 350 pages, part two surveys the full range of electrical machines: DC motors and generators, transformers in theory and practice, three phase induction motors, synchronous generators and motors, single-phase motors, and stepper motors — everything from the motors used in toys to the multi-megawatt generators in hydropower stations. It also explains active and reactive power and efficiency and heating constraints. Part three covers the fundamentals of industrial control and the basic components and circuits of power electronics, and their application to the control of DC and AC motors. Part four covers electric utility power systems — the generation, transmission, distribution, and pricing of electricity, as well as DC current transmission, solid-state controllers, and programmable logic arrays. There is also a chapter on harmonic analysis.

Electrical Machines is well organised and clearly laid-out, with sensible chapter and subsection divisions. Everywhere where there could be a diagram there is one (and usually on the right page). These diagrams are supplemented by black and white photographs of equipment — from diodes to dams — which help to keep real systems in mind. There are plenty of worked examples and each chapter has a set of problems, for which numerical answers are included. Electrical Machines, Drives, and Power Systems is an almost "textbook" textbook.

October 1997 [updated June 2003]

External links:

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- information from Theodore Wildi

Related reviews:

- books about engineering
- books published by Prentice Hall