Role of Electric Machines and Drives in Sustainable Electric Energy Systems
Sustainable electric energy systems require that we utilize renewable sources for generating electricity and use it as efficiently as possible. Towards this goal, electric machines and drives are required for harnessing wind energy, for example. Nearly one-half to twothirds of the electric energy we use is consumed by motor-driven systems. In most such applications, it is possible to obtain a much higher system-efficiency by appropriately varying the rotational speed based on the operating conditions. Another emerging application of variable-speed drives is in electric vehicles and hybrid-electric vehicles. This textbook explains the basic principles on which electric machines operate and how their speed can be controlled efficiently.
A New Approach
This textbook is intended for a first course on the subject of electric machines and drives where no prior exposure to this subject is assumed. To do so in a single-semester course, a physics-based approach is used that not only leads to thoroughly understanding the basic principles on which electric machines operate, but also shows how they ought to be controlled for maximum efficiency. Moreover, electric machines are covered as a part of electric-drive systems, including power electronic converters and control, hence allowing relevant and interesting applications in wind-turbines and electric vehicles, for example, to be discussed. This textbook describes systems under steady state operating conditions. However, the uniqueness of the approach used here seamlessly allows the discussion to be continued for analyzing and controlling of systems under dynamic conditions that are discussed in graduate-level courses.