Power quality improvement in DTC based induction motor drive using Minnesota rectifier

Abstract

This paper presents power quality improvement at the utility interface for a Direct Torque Controlled (DTC) induction motor drive by making use of a Minnesota rectifier. The proposed Minnesota rectifier for a 2.2 kW drive is designed, modeled and simulated in MATLAB/Simulink platform. The design of the proposed Minnesota rectifier is developed along with the necessary modifications required for making it suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. The performance parameters of the DTC drive fed by a 6-pulse uncontrolled converter is compared with the one fed by Minnesota rectifier for variable load conditions. The results show that the THD and power factor at the ac mains are improved perceivably even with the magnetic rating being as low as 40.94% of the drive rating.