基于永磁形状的BLDC永磁电机转矩分析与优化

无刷直流永磁电机因节能高效、便于使用等优势而受到广泛关注。然而，该类电机通常因空载感应电动势波形不理想而具有转矩脉动较大等问题。以24槽4极无刷直流永磁电机为例，基于气隙磁场调制理论分析了转子永磁型无刷直流电机的空载感应电动势等电磁特性，以磁场调制原理中的永磁初始磁动势源为切入点，探讨影响电机空载感应电动势波形系数的因素并揭示感应电动势形成的内在机理。首先，针对24槽4极传统转子永磁无刷直流电机的运行原理和空载气隙磁场进行分析，并根据得出的结论采取永磁体谐波削极的方式优化电机空载感应电动势波形系数，最后通过仿真验证了理论分析和优化方案的合理性。

Torque Analysis and Optimization of BLDC Permanent Magnet Motor based on Permanent Magnet Shape

The BLDC permanent magnet motor has received extensive attention because of its advantages such as energy saving, high efficiency and ease of use. However, this kind of motor usually had the problem of large torque ripple due to the no load EMF was not ideal. A 24-slot 4-pole rotor permanent magnet BLDC motor was taked as an example. Based on the theory of air gap magnetic field modulation, the electromagnetic characteristics such as the no-load EMF of the rotor permanent magnet BLDC motor were analyzed. The permanent magnet initial magnetomotive force source was used as an entry point to discuss the factors that affect the motor’s induced potential waveform coefficient and reveal the internal mechanism of the induced potential formation. First, the operation principle and no-load air gap magnetic field of a 24-slot 4-pole traditional rotor permanent magnet BLDC motor were analyzed, and the method such as permanent magnet harmonic pole cutting was adopted to optimize the waveform coefficient of the motor’s induced potential. Finally, the rationality of the theoretical analysis and optimization scheme is verified by simulation.