A new sensorless speed estimation strategy for induction motor driven electric vehicle with energy optimization scheme

This paper aims to propose a new sensorless speed control technique for induction motor (IM) drive suitable for electric vehicle applications using model reference adaptive system (MRAS) with a basic energy optimization scheme known as golden section method. The proposed MRAS is developed by using instantaneous and steady state values of a fictitious resistance (R) in the reference and adaptive models respectively. The optimization scheme generates the optimal level of rotor flux for machine operation and improves the efficiency of the drive system by bringing down the IM core loss. The developed overall scheme is immune to the stator resistance variation. Moreover, the unique formation of the MRAS eliminates completely the requirement of any flux estimation. Thus, the method is insensitive to the integrator-related problems like drift and saturation enabling an accurate estimation of speed even from zero to the rated speed. In this context, all the relevant studies are done in MATLAB/Simulink. A few experimental results are also presented to validate the simulation results.