In Part I we explored various motor technologies used today for industrial and traction motor design. Here in Part II we will explore another motor option: reluctance motors.
Lower-cost motor technologies exist that can be an attractive alternative to neo-based BL PM motors - and are not subject to unpredictable supply chains
There are three major types of reluctance motors: all three reluctance motors are non-permanent magnet, brushless motors. They are synchronous motors with a non-linear relationship between torque and current. The variable-reluctance step and switched-reluctance motors utilize the principle of magnetic attraction by inducing magnet poles within the soft-iron rotor, and by energizing a set of coils wound around stator teeth resident in the laminated stator. These two reluctance motors must be sequentially excited to achieve continuous, steady-state rotation. The design of all reluctance motors requires finite element analysis (FEA) software.
The recent trend toward using segmented laminations as a means to increase slot fill and facilitate automated fabrication of electric machines comes with a penalty of increased core loss at the segment joints.
