Methods Research Of Weakening Cogging Torque In Flux Reversal Machine

Flux reveral machine (FRM) is a novel doubly salient permanent-magnet machine (DSPM). It was brought faward by R.P.Deodhar and others. And they carried on the research of preliminary theory and experiment. Thereafter, some scholars studied structural design and electromagnetic field of FRM. At present, the research of FRM is still in the initial stage and only stays in the step of preliminary theory research and protype experiment. There are still many deficiencies in the structure and the performance. The basic structure and working principle of FRM is discussed in this paper. It's mathematic model is deduced. The methods of optimum designing magnetic structure in FRM, which based on fully considering of the magnetic field characters, are proposed in this paper. The methods weaken cogging torque in FRM effectively and make it operate steadily on the premise of guarantee its own merits.Finite element method (FEM) is used to solve the electromagnetic field of FRM. The electromagnetic field distribution and operational feature of FRM can be analysed through the computed results. To obtain ideal model, the electromagnetic fields of different stator and rotor structures are analysed. The three-phase 6/8 polar FRM structure is acquired finally. The permenant-magnet is NdFeB and its remnant magnetism and coercive force are both high. The width poles and corresponding narraw poles of the stator is paired in the space. The rotor laminated core is divided into three sections along axial direction. This new structure, which is based on the the premise of maximizing its specific power, can weaken cogging torque effectively and output optimal running performance.Corresponding control strategy suit to this new class of machine, which combines the control theory of brushless direct current motor and switch reluctance motor, is concluded. The method is variable angle and voltage pulse-width modulation (PWM) control combination. And the hardware control system is briefly designed, which takes DSP chip TMS320LF2407A as the core device.