Analysis of Torque Ripple Reduction in Induction Motor DTC Drive with Multiple Voltage Vectors

Abstract

This paper shows an analysis of torque ripple reduction in modified DTC algorithm by using multiple voltage vectors with the appropriate multilevel hysteresis controller. A short theoretical background of classical and proposed DTC algorithm was given at the beginning. Experimental results of the proposed DTC algorithm, implemented on digital signal processor F2812, were analysed in comparison with classical DTC. It is shown that the torque ripple can be reduced by selecting voltage vectors with an appropriate intensity. Motor current oversampling was used to analyse the estimated torque behaviour during one DSP sampling period. Furthermore, the analysis of torque ripple reduction with oversampled torque values was conducted in relation to the number of available voltage vectors. The analysis shows that the proposed DTC algorithm allows significant torque ripple reduction while retaining the simplicity, small computational burden and good dynamic characteristics of the classical DTC.

Keywords

• digital signal processors
• induction motor
• multilevel comparator
• ripple reduction
• torque control