One should get as much benefit as possible from the considerable progress made in the field of control theory. Of course, not all nonlinear control methods apply to electrical AC machines, but some of them are accessible. In this respect, special focus is made on the topics of sensorless nonlinear state high gain observers, sampled output data measurements, adaptive and robust nonlinear controllers, and output feedback controllers. The most significant developments in these topics, and their practical applications to electrical system control, are described clearly in this book, as well as some new research topics. This book is intended for a wide variety of readers, including academia and industry researchers, graduate students and their professors, engineers, and practitioners. Although it includes many aspects of the theory, it is nonetheless beneficial to practitioners who will be able to use the methods without necessarily understanding every single detail of the theory. It will also be useful for new researchers in the field of AC machines control. For students, the main prerequisites are undergraduate courses on linear and nonlinear system control, on electric machines.