Study On Novel Topologies Self-Commutating Low-Speed Reluctance Motors

With the development of society and technology, the exploitations and researches of low speed motors for direct drive applications have been greatly advanced, and there has been lots of researchers at home and abroad going for low speed and high torque motors for direct drive applications without decelerators in current years, and how to get high torque at low speed is always the key point of these researches. Based on conventional tiny teeth and variable reluctance (VR) motors, this paper presents both dual-stator (DE-SCLRM) and dual-rotor (DR-SCLRM) configurations as the novel topologies of self-commutating low speed reluctance motors (SCLRM), without any gearbox and permanent magnet. Only with a static inverter composed of six diodes connected to the specially arranged stator windings, this series of motors are capable of self-commutating when working on the normal three-phase ac source for low speed operation, which is only dozens of revolutions per minute or even more lower. Since DE-SCLRM and DR-SCLRM both have two tooth-layers, their inner spaces can be highly utilized, so compared to normal SCLRM of similar construction the output torque will be further more increased, which provides a new method to the research of low speed and high torque motors for direct drive applications.This paper has introduced the typical configurations of dual-excitation (dual stator) self-commutating low speed reluctance motor (DE-SCLRM) and dual-rotor self-commutating low speed reluctance motor (DR-SCLRM), as well as the connections of the stator windings and the self-commutating principle applied to both topologies when working on the normal three-phase ac source. The mathematics models and the equivalent linear magnetic circuits of the dual-tooth-layer self-commutating low speed reluctance motors will be established, from which we can derive the mathmatic expressions of the both outer and inner inductance and magnetic torque. Comparison studies between different topologies of the dual-tooth-layer SCLRM will also be carried out on the aspects of the magnetic field distribution, flux, inductance, current and torque capacity by 2D finite element transient simulation models in Maxwell v12. Further more, according to the electromagnetism design philosophy of the novel dual-tooth-layer SCLRM, influence of the configuration parameters such as stator teeth number per pole, air-gap length, tooth width and tooth height on torque will be analysed, and the electromagnetism and configuration designs of prototype DR-SCLRM will be accomplished as well.