The adoption of advanced technical solutions to match the requirements of energy efficiency is becoming increasingly essential, promoting a gradual transformation in the field of mechanical actuators and shifting the attention to more electric and efficient systems. The main driving force is the need for new solutions in specific application areas such as railway traction, electric and hybrid vehicle applications, 'more-electric' aircraft, electric ship propulsion, and general high-power applications. Multi-phase motor drives are gaining a growing interest because they permit a boost in torque and power density, allowing the design of very compact high efficiency drives with positive reliability outcomes. Traditional solutions for electric drive/generation systems, based on three-phase machinery, are not necessarily the best solutions, however. Moreover, since the electric machine is either typically decoupled from the mains, or the actual power system is an autonomous one, the number of phases of the machine does not have to be limited to only three. The resultant 'multiphase machines' offer numerous potential advantages over their three-phase counterparts. This book aims at presenting the new research results concerning multiphase machines and drives, AC multiphase power converters and their applications, as related to 'more-electric' transport.