本論文探討感應馬達之直接轉矩控制法，所產生轉矩漣波過大的現象，並實現一種以固定磁通變量之直接轉矩控制法，有效抑制轉矩漣波。 感應馬達之直接轉矩控制法有簡單、易於實現、且受參數變化影響不大的特性，但直接轉矩控制法最大的問題在於有限的電壓向量做切換時之轉矩變化，造成馬達噪音及震動的產生，多以空間電壓向量調變技術之控制法來克服，是以更多的電壓向量與高階磁滯比較器能使磁通變化平順，但增加電壓向量與磁滯比較器的階層，無法有效消除轉矩漣波的產生，原因於開關元件並無法快速的響應。 因此本論文提出固定磁通變量直接轉矩控制法，藉由即時的空間電壓向量運算，保持固定磁通變量，有效抑制轉矩漣波的產生，並在磁通誤差量大時使用傳統方法，而當磁通誤差量到達目標範圍後改為固定磁通變量法，如此即可實現兼顧暫態與穩態性能之控制法。 本研究以定點式數位訊號處理器與智慧型功率模組為基礎，實現全數位化驅動器，不但有效簡化電路，亦提升了系統之彈性，最後以實驗證實其可行性。 This research investigated the phenomenon of over-large ripple generated by direct torque control operated induction motors, and developed a fixed flux variation direct torque control to sufficiently inhibit the ripple. Direct torque control is uncomplicated, easy to practice, and not affected much by factor variations. However, a huge problem of direct torque control is that switching limited voltage vector results in a torque change, and this change causes noise and vibration of the motor. This problem is usually solved by spatial voltage vector adjusting control, which uses more voltage vector and advanced hysteresis comparators to stablize the variation of flux. However, increasing voltage vector and the level of hystersis comparator cannot eliminate torque ripple efficiently because the switch element cannot follow this rapid adjustment. This thesis proposed fixed flux variation direct torque control to stabilize the flux variation and inhibit torque ripple generation by instant spatial voltage vector computation. The traditional method is used when flux deviation is big; the fixed flux variation method is used when the flux deviation decreases to the targeted range. Therefore, this newly developed method accomplishes both transient and steady state control. This research developed a full-digital drive based on the fixed-point digital signal processor and intelligent power module. This drive not only efficiently simplifies the circuit, it also increases the flexibility of the system. Finally, the experiment confirmed the feasibility of this method.