Unity power factor converter-inverter fed vector controlled cage motor drive without mechanical speed sensor

This paper presents a comprehensive analysis of a vector controlled induction motor drive. The motor is fed from a current controlled converter-inverter system which acts as an ideal frequency changer and offers four quadrant operation. An intelligent and robust closed loop speed control of the cage induction motor drive is obtained using a fuzzy logic based sliding mode speed controller. The motor speed is estimated using a flux model based observer which uses terminal conditions of the motor and its parameters and it eliminates the use of a mechanical speed sensor. The simulated results reveal that the proposed drive system exhibits a high level of performance at input/output ports (AC mains and the motor) of the integrated converter-inverter link. The potential applications of this drive are identified.