Research On Design And Optimization Of Improved Three-phase Flux Reversal Machine

Flux reversal machine(FRM) is a novel doubly salient permanent machine. The concentrated stator pole winding is adopted and the rotor is made of silicon steel sheet only. A pair or more permanent magnets which are magnetized in opposite direction are placed on each stator pole face. The phase flux variation is bipolar with the rotor rotation. FRM has numerous advantages such as high efficiency, simple construction, easy to manufacture, control agility and has a considerable potential in the fields of automotive generators, wind energy generation,low-speed servo drive and so on.This paper introduces the research background and significance of FRM firstly. With reference to relevant literatures both domestic and abroad, the history and development situation of the research on FRM is introduced. The basic structure and operating principles of FRM is expounded next. For the problem of large permanent magnet flux leakage under the stator pole, an improved topology called improved flux reversal machine(IFRM) is proposed.Secondly, the magnet circuit models of FRM and IFRM are created. Based on the magnet circuit models, the main flux and the flux leakage are calculated and contrasted in detail to prove the rationality of improved topology. An equation reveals the relationship between the output power and the electromagnetic design parameters is developed and a test prototype is designed. Distribution of magnet field, permanent magnetic flux linkage, back EMF, electromagnetic torque are calculated by both equivalent magnetic circuit method and finite element method. It reveals that the magnet circuit models created is scientific and reliable by comparison made between the results of equivalent magnetic circuit method and finite element method.Then, the Taguchi method is introduced into the local optimization of IFRM. The maximum average electromagnetic torque and the minimum torque ripple are set as optimal objects, and several groups of parameters are picked up to perform an orthogonal experiment. According to the analysis comparison of the experimental results, an optimal combination is selected and multi-object and multi-parameter optimal design is finally achieved.At last, the comparative study between the IFRM and PMSM are performed, including the structures, electromagnetic torque, torque density, ratio of torque and permanent magnet quantity and so on. It deepens understanding of IFRM.