Design methodology and sensorless control of electric propulsion system using DTC-SVM

Electric propulsion system (EPS) employing Induction Motors (IM) have gained acceptance due to their robust structure, reliability, technological advancement and low cost. This paper presents the technical considerations and design methodology of EPS for urban cars. Direct torque control (DTC) is a prominent technique in controlling the IM due to its easy configuration and fast performance. Nevertheless, it generates high torque ripple coupled with variable switching frequency. To get sophisticated results like ripple free torque and constant switching frequency, IM can be controlled by DTC scheme using the space-vector modulation (SVM) technique. The speed of the motor is estimated in limp-home mode operation of the vehicle by rotor flux based model reference adaptive system (MRAS). The performance of IM in limp-home mode of electric vehicle using DTC and DTC-SVM techniques considering the drive cycle are presented.