Design And Characteristic Analysis Of W-type PM Reverse Salient Permanent Magnet Synchronous Motor

At present,the country has launched the "dual carbon" strategy,and high-efficiency and energy-saving motors have become the focus of domestic and foreign scholars engaged in motor research direction.In recent years,with the continuous development of rare earth permanent magnet materials with high coercivity and other high-quality characteristics,the motor industry continues to bring forth the new.Compared with the earlier electric excitation,the permanent magnet is now placed in the motor as the excitation source,which makes the motor the advantage of high power density,etc.And it is widely used in other industrial fields.Because the permanent magnet is fixed in the rotor,it is difficult to adjust the magnetic field after prototype processing,which limits its further development in the direction of the flux-weakening.In order to solve a series of problems,such as the permanent magnet synchronous motor（PMSM）in flux-weakening speed regulation and easy demagnetization of permanent magnets,this paper innovatively proposes a W-type negative-salient permanent magnet synchronous motor（NSPMSM）.This work initially discusses the current state of research and development tendency in traditional motor-based NSPMSMs,and meanwhile proposes a w-type NSPMSM with a novel structure.The structure of the W-type NSPMSM is described,and the operating principle and equivalent magnetic circuit model.Secondly,to make the NSPMSM has better performance,on the basis of the magnetic circuit structure analysis,finite element method respectively from the permanent magnet thickness,magnetic bridge length and eccentric distance and crack length analysis influence the parameters of the electromagnetic torque,at the same time further analysis of the inductance of the motor and air gap flux density,and studied the motor fault-tolerant performance,It provides an effective basis for evaluating the performance of reverse salient permanent magnet synchronous motor.Finally,the principle of the motor flux-weakening is described,the optimal control strategy is selected,and the flux-weakening properties of NSPMSM with negative-salient characteristics are analyzed comprehensively with the help of the finite element method.The factors affecting motor flux-weakening such as power factor angle are studied,and the constant power speed range of the motor is calculated.The finite element analysis is consistent with the theoretical analysis,which fully demonstrates the validity and feasibility of the w-type NSPMSM.This scheme provides a new attempt to solve the difficulty of flux-weakening speed regulation of traditional PSPMSM and has theoretical and practical value.