A 12-sector space vector switching table for parallel-connecting to dual induction motors fed by matrix convertor based on direct torque control

Abstract

The present study proposes an improved switching table of direct torque control (DTC) for two parallel connection induction motors fed by matrix convertor. This method is based on the mean control strategy and allows the use of all switching states of matrix convertor. These functions represent the relationship between the change rates of the torque, flux, and input power factor of motors and the output voltage vector and input current vector of the matrix convertor. The effect of matrix convertor switching states on the change rate of the torque, flux, and input power factor is established by averaging approach and is done in the four improved switching tables. Finally, the optimal switching state is chosen from the switching tables. The results show that overshoot of motors speed to following reference input is 1% of reference speed less than conventional methods and also, oscillation of motors torque is less than conventional methods. Numerical results show the effectiveness of the proposed approach and prove its reliability for industrial uses.Article HighlightsIn summary, the highlight of this research is the simultaneous control of torque and speed of two electric motors by an inverter. In such a way that even in different conditions of motors load, speed and torque follow the reference values well. Also, using the advantages of DTC algorithm and applying it to use matrix convertor are the highlights of this research.