A Design Procedure for Hybrid Rotor PMSM to Achieve Wide Constant Power Speed Ratio

Interior permanent magnet (IPM) machines are more commonly used in applications where constant power vs. speed operation is required. However, achieving IPM rotor design for a wide constant power speed ratio (CPSR) requires an iterative design process, thus driving design cycle time and cost higher. In this work, a design methodology is proposed to achieve wide CPSR using combinations of different types of pre-designed rotor cross-sections, i.e., hybrid rotor machines. The design constraints developed in this work are broadly applicable to any synchronous AC machine that allows for a relative offset between PM and reluctance torque components as an additional design degree of freedom.