Condition monitoring of electrical machines and drive systems is a vital factor to achieve efficient and profitable operation of a large variety of industrial processes. Similarly, parameter estimation is important for the machine designer, and invaluable to the operator of modern drivesimplementing various types of controllers. It is also necessary to know the machine parameters for a number of simulation purposes. The chapters in this volume cover recent trends and advances in these and other areas, including sections on on-line and off-line parameter estimation of smooth-air-gapand salient-pole electrical machines, their diagnosis and condition monitoring. New real-time monitoring devices, vibroacoustic techniques, and the symptoms and possible causes of failures of electrical machines are also discussed. In the book a unified and in-depth physical and mathematical analysis of the various parameter estimators and condition monitoring methods is presented. For this purpose, where possible, space phasor theory is utilized and the most recent and modern developments in the field areincorporated.