Hybrid stepping motor with permanent magnets in stator-presentation, parameter calculation and design

In order to enhance the operating performance and simplify the design and analysis of the hybrid stepping motor (HSM) normally with permanent magnet in rotor (RHSM), a novel HSM with permanent magnets in stator, namely the stator permanent magnet stepping motor (SHSM), is presented in this paper. Structural topology of the SHSM is firstly put forward. Operating principle of the SHSM is analyzed and compared with that of the doubly salient permanent magnet (DSPM) motor. Based on which, the main electromagnetic properties, such as PM flux linkage, back EMF, torque, and power, are analytically derived. In addition, the normalized calculation method and corresponding electromagnetic design method applicable to the SHSM are also proposed. A 2-phase 8-pole SHSM is designed and built for exemplification. Both finite element analysis (FEA) and experimental results of the prototype are given to verify the theoretical analysis and to confirm its working feasibility.