Improvements of torque ripple reduction in DTC IM drive with arbitrary 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 of research work on improving these algorithms. This paper presents the DTC algorithm with discretized voltage vectors based on the use of conventional switching table (ST-DTC). This algorithm enables a significant torque ripple reduction by defining the corresponding number of the given voltage intensity while retaining calculation simplicity and fast torque response typical of the ST-DTC algorithms. The proposed algorithm has the ability for its automatic modification depending on the defined number of voltage intensities by the user. In a simple way, the proposed algorithm enables the influence compensation of the induced electromotive force for a torque error at high speed. Experimental results obtained by using MSK2812 digital control platform confirm the significant reduction of the torque ripple with an increase of the number of defined voltage intensities.