轴向磁通电机永磁体尺寸沿径向变化较大,且定子绕组有效长度较短,因此气隙磁场径向端部磁密值的削弱不可忽略。以一台7 k W、4000 r/min表贴式双转子轴向磁通永磁电机为例,采用三维有限元法分析气隙磁场端部效应,并得出结论:气隙长度δ...轴向磁通电机永磁体尺寸沿径向变化较大,且定子绕组有效长度较短,因此气隙磁场径向端部磁密值的削弱不可忽略。以一台7 k W、4000 r/min表贴式双转子轴向磁通永磁电机为例,采用三维有限元法分析气隙磁场端部效应,并得出结论:气隙长度δ增大至2 mm时对内、外端部磁场影响程度相同;极弧系数αp增大,内端部气隙磁密变化速度先减小后增大,外端部恰相反,αp=0.75时分别达到速度最小值与最大值;外端部气隙磁场随斜极角度呈明显的周期性变化,气隙圆环外径至平均半径之间气隙磁密周期变化范围为[θz,2θz)。展开更多
With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increas...With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increased.To solve the problem of oversized cogging torque of axial flux PMSM,a rotor topology with hybrid permanent magnet is proposed to weaken the cogging torque.Firstly,the expression of the cogging torque of the axial flux motor is derived,and the influence of the pole-arc ratio of the permanent magnet on the cogging torque is analyzed.Secondly,the rotor structure with hybrid permanent magnet is adopted to reduce the cogging torque.According to the analytical analysis,the constraints of the size and pole-arc ratio between the hybrid permanent magnets are obtained,and the two permanent magnets related to the minimum cogging torque are determined.And the analysis results are verified by the finite element simulation.Furthermore,the motor performance with and without the hybrid permanent magnet is compared with each other.Finally,the cogging torque is significantly reduced by adopting a rotor structure with hybrid permanent magnets.展开更多
文摘轴向磁通电机永磁体尺寸沿径向变化较大,且定子绕组有效长度较短,因此气隙磁场径向端部磁密值的削弱不可忽略。以一台7 k W、4000 r/min表贴式双转子轴向磁通永磁电机为例,采用三维有限元法分析气隙磁场端部效应,并得出结论:气隙长度δ增大至2 mm时对内、外端部磁场影响程度相同;极弧系数αp增大,内端部气隙磁密变化速度先减小后增大,外端部恰相反,αp=0.75时分别达到速度最小值与最大值;外端部气隙磁场随斜极角度呈明显的周期性变化,气隙圆环外径至平均半径之间气隙磁密周期变化范围为[θz,2θz)。
基金supported by the Natural Science Foundation of Hubei Province(No.2019 CFB759)。
文摘With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increased.To solve the problem of oversized cogging torque of axial flux PMSM,a rotor topology with hybrid permanent magnet is proposed to weaken the cogging torque.Firstly,the expression of the cogging torque of the axial flux motor is derived,and the influence of the pole-arc ratio of the permanent magnet on the cogging torque is analyzed.Secondly,the rotor structure with hybrid permanent magnet is adopted to reduce the cogging torque.According to the analytical analysis,the constraints of the size and pole-arc ratio between the hybrid permanent magnets are obtained,and the two permanent magnets related to the minimum cogging torque are determined.And the analysis results are verified by the finite element simulation.Furthermore,the motor performance with and without the hybrid permanent magnet is compared with each other.Finally,the cogging torque is significantly reduced by adopting a rotor structure with hybrid permanent magnets.
