Design and Analysis of Single-Phase, Two-Speed, Line-Start Synchronous Reluctance Motor for Ceiling Fan Applications

In this paper, a single-phase, line-start synchronous reluctance motor is proposed for low-power, outer rotor ceiling fan applications. Different rotor bar and flux barrier shapes and their combinations are investigated to meet the following requirements: (a) motor starts from zero speed and reaches the synchronous speed when rated voltage is applied, and (b) motor steps-out of synchronism and operates at lower speed when the fraction of the rated voltage is applied. The investigation of the motor designs is carried-out in a standard finite element method-based platform. A 16-pole synchronous reluctance motor with an asymmetric cage-barrier combination is chosen from the investigated rotor designs, and it is further analyzed in terms of efficiency. It is also compared against a conventional single-phase induction motor with similar outer dimensions, and considerable improvement in efficiency is observed. The presented motor design adheres to the standard radial dimensions and delivers higher efficiency than all ceiling fan motors without permanent magnets and power electronic converters that are reported in the literature.