A Novel Self-Commutating Low-Speed Reluctance Motor for Direct-Drive Applications

This paper presents a novel low-speed and high-torque motor, self-commutating low-speed reluctance motor (SCLRM), for direct-drive applications. With six diodes connected to the stator windings, it is capable of self-commutating when working on normal three-phase ac source for constant-speed operation. It provides an uncomplicated and low-cost method to increase the torque capability of the traditional vernier-type motors without the requirement of permanent magnets and inverter drive. In this paper, the basic theory of SCLRM is presented, including the operation principle and the mathematical models from which the calculation equations of the inductance parameters as well as the electromagnetic torque are deduced. Besides, the simulation and implemental results are shown, and the reasons of the improvement of the torque capability are analyzed. Moreover, an inverter drive system for SCLRM whose topology is different from that of the standard three-phase inverter is proposed for variable-speed applications