Improvements of torque ripple reduction in DTC IM drive witharbitrary number of voltage intensities and automatic algorithm modification


Abstract: Techniques of direct torque control (DTC) are very common in high-performance electric motor drives.Retaining the good features of the conventional DTC and reducing torque ripple have been the subject of many years ofresearch work on improving these algorithms. This paper presents the DTC algorithm with discretized voltage vectorsbased on the use of conventional switching table (ST-DTC). This algorithm enables a significant torque ripple reductionby defining the corresponding number of the given voltage intensity while retaining calculation simplicity and fast torqueresponse typical of the ST-DTC algorithms. The proposed algorithm has the ability for its automatic modificationdepending on the defined number of voltage intensities by the user. In a simple way, the proposed algorithm enables theinfluence compensation of the induced electromotive force for a torque error at high speed. Experimental results obtainedby using MSK2812 digital control platform confirm the significant reduction of the torque ripple with an increase of thenumber of defined voltage intensities.

Keywords: AC motor drive, variable speed drive, direct torque control, torque ripple reduction, electromotive forcecompensation

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