BLDC motor drive controller for electric vehicles

In this thesis, direct torque control of BLDC motors and a novel back-EMF zero crossing detection based sensorless control technique has been presented. Two novel fault tolerant systems for motor-drive controllers have also been recommended. Proposed techniques show tremendous experimental improvement to the present state of the art while used in electric vehicle application. They are simple; reduce sensing circuitry and cost of motor-drives while increasing the overall reliability of electric vehicles. Stability of BLDC motors are analysed by Lyapunov's second method and a novel stability analysis condition is introduced. This study improves overall safety and efficiency of electric vehicles.