永磁体失磁对永磁伺服电机性能的影响研究

Influence of Permanent Magnet Demagnetization on Performance of Permanent Magnet Servo Motor

永磁体失磁是永磁伺服电机常见故障之一,其失磁程度的不同将会造成电机性能不同程度的改变。以一台12.5 k W卷烟自动化设备永磁伺服电机为例,研究了永磁电机失磁对气隙磁场和电流的影响。基于傅里叶谐波分解理论对电流进行谐波分解,给出了电流谐波随不同永磁体失磁率的变化规律。在此基础之上对电机的功率因数、效率、损耗、最大转矩及其过载能力进行研究,给出了电机不同性能参数随转子永磁体失磁率的变化规律,并进一步揭示了电机失磁对电机性能影响的机理,所得出的结论为进一步研究永磁伺服电机故障容错及其可靠性奠定了一定的基础。

Permanent magnet demagnetization is a common fault in permanent magnet servo machines, and the influ- ence of the demagnetization in different degrees on the machine is also different. Taking a 12, 5 kW permanent magnet mo- tor used in cigarette automatic equipment as an example, the influence of permanent magnet demagnetization on the motor current and magnetic field was studied. Basing on the theory of Fourier harmonic decomposition, the variation of different current harmonics was obtained. And then the power factor, efficiency, losses, maximum torque and overload capacity were analyzed comparatively, when the machine operates at different demagnetization conditions. By analyzing the variation of the motor performance, the influence mechanism of the permanent magnet demagnetization on the motor performance can be discovered. The obtained conclusions may provide useful reference for the research of the fault and reliability on the perma- nent magnet motors.