Permanent-magnet (PM) brushlessBrushless synchronousSynchronous machines have been widely used in many industrial applications, such as electric propulsion and traction systems, due to their high working efficiency, high reliability and low noise. Increasing torque, reducing torque rippleTorque ripple, and lightweight structure are the key issues for the development of PMBrushlessSynchronous machines. The rotor pole pattern is one of the important aspects that influence the torque output significantly. In this chapter, the advantages and applications of PM machines with typical pole patterns are presented and discussed. Then, the main objective of this monograph is presented.