Comparison of Direct Torque Control Techniques in Induction Motor Drives in Terms of Electromagnetic Conducted Emissions

This paper presents a theoretical and experimental characterization of the electromagnetic conducted emissions of DTC induction motor drives. In particular three DTC strategies are focused: the Classic DTC, the DTC-SVM and the DTC EMC. A new theoretical analysis of the common-mode voltage spectrum obtained with all of the three DTC strategies is presented, which is an useful analytical tool for the emissions' prevision. Moreover, an experimental analysis of the conducted emissions has been performed in a frequency range from 0 to 30 MHz, whereby suitable electrical values to be measured and suitable measurements systems have been adopted.