本論文主要針對永久磁石充磁方式對永磁馬達的轉矩特性影響進行分析，本文所指轉矩特性即轉矩漣波(Torque ripple)，包含齒槽效應所造成之頓轉轉矩(Cogging torque) 以及驅動電流波形對應反電動勢(Back-EMF)波形之偏異度，並應用有限元素法(Finite Element Analysis, FEA)模擬軟體來模擬永久磁石經由不同充磁磁場充磁後，對氣隙磁通分佈以及反電動勢波形的影響。
為驗證所設計之充磁治具能與實際將永久磁石充出所需特性，本文將透過FEA模擬與實驗交叉驗証馬達轉矩特性與永久磁石表面磁通分佈之關聯性。未來實務上對永磁馬達可針對磁石充磁條件進行設計，在不須採用磁石修形、斜槽(Skew)與定子修形等繁雜設計條件下獲得所需的轉矩特性。

SUMMARY
The torque characteristics in BLDC motors are studied in this thesis by varying the magnetization patterns applied to the permanent magnet. FEA (Finite Element Analysis) is used to simulate and analyze the relationship between the anisotropic magnet magnetization and the flux density distribution in the air gap. The target is to obtain sinusoidal Bake-EMF waveforms for low torque ripple operation. The effect of such magnetization on cogging torque is also investigated.
In this study, a magnetizing fixture is designed and fabricated to magnetize a ring anisotropic radial-alignment magnet. The simulation and test results show that the Back-EMF can achieve sinusoidal and the cogging torque can be reduced.

Keyword : cogging torque ; magnetization field ; alignment field ; B-EMF ; torque ripple

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