本論文的目標是要提出減少永磁同步馬達（Permanent Magnet Synchronous Motor, PMSM）驅動器的轉矩及速度漣波之技術，在傳統的直接轉矩控制法（Direct Torque Control, DTC）中，由於只有六個有效向量與兩個零向量可供輸出的選擇，無法切換出相當平順的弦波電壓供給永磁同步馬達，因此傳統的直接轉矩控制僅使用這些少量的電壓向量來驅動馬達可能會造成我們不希望的轉矩和電流漣波，為了改善這部份的性能，我們可以應用空間向量調變（Space Vector Modulation, SVM）的基礎來獲得新型直接轉矩控制的演算方式，此種方式，可以把它視為一種離散的空間電壓調變（Discrete Space Vector Modulation, DSVM）技術。 這種方法相較於傳統的直接轉矩控制，它可以合成出更多電壓向量的數量，也因為向量的增加，我們可以依據磁通誤差和轉矩誤差定義出更精確的切換表做電壓的選擇。 最後由模擬及實驗的結果來比較本論文所提出的直接轉矩控制法與傳統的直接轉矩控制法的效能，由結果可以看出本論文所提出的直接轉矩控制法，在穩態的控制效能上確實優於傳統的直接轉矩控制法。 The objective of this thesis is to present the techniques for reducing the torque and speed ripples of a Permanent Magnet Synchronous Motor (PMSM) drive. Observing traditional direct torque control (DTC), because of only six effective and two zero output voltage vectors that could be chosen, it is difficult to produce a sinusoidal voltage to Permanent Magnet Synchronous Motor. To less voltage vectors applied to the machine of the basic DTC scheme may cause undesired torque and current ripple. An improvement of the drive performance can be obtained for DTC using the space vector modulation (SVM) with fixed time interval to get equivalent voltage vectors. In this way a sort of discrete space vector modulation (DSVM) is introduced. Based on the above concept, more voltage space vectors can be synthesized with respect to those used in basic DTC technique. More voltage vectors allows the definition of more accurate switching tables in which the selection of the voltage vectors is made according to the flux error and torque error. The simulation and experimental results of the proposed DTC were compared with a conventional DTC. Comparisons that the proposed DTC has better control performance than the conventional DTC.
