This concise book focuses on the reliability of traction electrical drives. The first chapter presents the Lz-transform approach for the comparative analysis of the fault tolerance of multi-motor electrical drives with multi-phase traction motors. The second chapter then provides an estimate of the value of the operational availability and performance of a diesel-electric multi-drive propulsion system, while the third chapter introduces the concept of a more electric aircraft. Lastly, the fourth chapter analyzes the requirements for multi-phase permanent-magnet motors applicable in various aircraft systems.