Improved Direct Torque Controlled PMSM Drive for Electric Vehicles

Direct torque control (DTC) scheme for permanent magnet synchronous motor (PMSM) drive is one of the perceptible vector control schemes in industrial applications providing a faster dynamic response. Nevertheless, the existence of hysteresis controllers and imperfect switching tables consequences more torque ripples and poor flux response. A highly precise DTC for two-level voltage source inverter (VSI) fed PMSM drive gaining less ripples in torque and flux response is proposed in this paper. The proposed DTC is functioned by computing the reference voltage vector (VV) in the stationary reference frame. The VV table is formed depending on the sector and size of the reference VV. Therefore, the closest discrete VV to the reference VV is chosen to operate PMSM drive in better manner producing less ripples in torque and flux response. In addition, the reduction of switching frequency for proposed system is gained by employing redundant switching combinations of null VV. The steady-state and dynamic responses of existing and the proposed DTC schemes are analyzed. Also, loss evaluations of PMSM drives are incorporated. The results are compared with the existing DTC scheme. From these entire results, proposed DTC operated PMSM drive is validated exhibiting favorable response for smooth operation of Electric Vehicles. © 2022, The Institution of Engineers (India).