Sensorless vector control of induction motor drive for electrical vehicle application

In this paper, an electric vehicle drive using alternating current (AC) induction motor with low cost and robust construction is presented. This approach is applied to an already existing commercial utility electric vehicle where previously used direct current (DC) series motor was replaced by the new AC induction motor. A voltage source inverter is used for three-phase squirrel cage induction motor which requires supply of DC voltage from vehicle battery system. A new DSP based voltage inverter is designed for the proposed drive. The used processor realizes the field oriented control algorithm with torque and flux closed loop control. The processor computes the motor speed using speed observer. In this paper system description, control algorithms realization, and speed computation are presented. The paper also includes the simulation and experimental results of the discussed system The proposed drive does not have a speed sensor, which make the solution sensorless which reduces the cost and is reliable on speed sensor faults.