本文旨在研製具電流諧波抑制之六臂型三相同步電動機的驅動器。文中以六臂型架構，個別獨立控制同步電動機三相繞組，其驅動器控制則採用單極性弦式脈波寬度調變，可提高系統直流鏈的電壓利用率。本研究提出二種電流諧波抑制策略:正常運轉下利用電流預測法直接抑制零軸電流，降低諧波含量;單相繞組故障時，修正未故障的另二相電流，以此二相電流角度相差60度並配合零軸感應電動勢作補償，降低不平衡條件下的轉矩漣波。最後利用轉速發電機估測轉子磁極角位置及轉速，配合同步旋轉座標系統轉換完成電流與轉速閉迴路控制。
本文以模擬軟體Matlab/Simulink完成永磁式同步電動機驅動器、轉速及電流閉迴路控制、故障控制與諧波抑制之分析。系統以數位控制器TMS320F28069作為控制核心，控制策略皆以軟體完成，減少電路元件，提高可靠度。實際測試之轉速為180rpm，負載為2N-m。在正常運轉下，三相電流總諧波失真率平均值由10.43%降至1.81%。a相故障後，電流總諧波失真率由4.46%降為2.96%，轉矩峰對峰值由0.68N-m降至0.66N-m。實測結果顯示，本文之降低電流諧波含量控制策略具可行性。

The thesis focuses on the development of low total harmonic distortion (THD) of current for a six-leg inverter for three-phase permanent-magnet synchronous motor (PMSM) drives. The power circuit of six-leg three-phase inverter will provide independent operation for each phase of PMSM to raise the utilization factor of dc-link voltage. In addition, two types of current harmonics mitigation control are proposed: one for normal operation and the other for the case when single phase winding fault occurs. The former uses current prediction to suppress the zero-axis current, while for the latter, adjusting the phase angle difference of the other two windings to 60 degrees and introducing zero-axis back electro-motive-force compensation will reduce THD of current as well as torque ripple under unbalanced condition. Finally, an auxiliary generator is used to measure the position and speed of the rotor to facilitate the coordinate transformation of feedback current for current and speed closed-loop control.
In this thesis, Matlab/Simulink is used to simulate the proposed PMSM drive including current and speed closed-loop control, fault tolerance control as well as harmonic mitigation. The digital signal processor, TMS320F28069, is adopted as the control core and the program is compiled by C language, thereby reducing the circuit components and enhancing the reliability. Experimental evaluation for current harmonics mitigation control is conducted at 180 rpm with a load of 2 N-m. Under normal operation, the THD of current is reduced from 10.43% to 1.81%. Whereas, when single phase winding fault occurs, the THD of current is reduced from 4.46 % to 2.96 %. Besides, peak to peak value of torque is dropped from 0.68 N-m to 0.66 N-m. The experimental results show the feasibility of the proposed current harmonic control strategy.

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