- This event has passed.
Direct torque control methods for a three-level inverter fed induction motor drive
November 7, 2019 @ 11:00 am - 12:00 pm
Ph.D Seminar Talk II
Name : Pratibha Naganathan (EE15D003)
Guide : Dr. Srirama Srinivas
Date : November 7, 2019 (Thursday)
Time and Venue : 11:00 am at ESB 244
Title: Direct torque control methods for a three-level inverter fed induction motor drive
DC Members :
Dr. Krishna Vasudevan (Chairperson)
Dr. Mahesh Kumar (M)
Dr. Kalyan Kumar B (M)
Dr. Srinivas Reddy K (ME)
AC induction motors are used in various industrial applications and superior control characteristics can be obtained using advanced control methods like vector control and direct torque and flux control (DTC) methods etc. Overcoming the main drawback of variable switching frequency of the classical DTC method, two, constant switching frequency (CSF)-DTC methods exploiting the three-level inverter (TLI) features will be presented in the present talk. The proposed methods are aimed at reducing the motor torque ripple especially at low speed operation. Both the methods use modulators and characteristics of the Pulse Width Modulation (PWM) mainly determine the motor drive performance. Detailed analytical expressions describing complete harmonic characteristics of the TLI obtained using double Fourier integral approach will also be discussed. Superior harmonic performance obtained with the proposed PWM methods are compared to the existing PWM methods. Drawback of one of the envisaged CSF-DTC techniques entering into over-modulation is rectified at higher motor speeds and a smooth slide-over using zero offset voltage to carrier signals is recommended to overcome the issue. The proposed CSF-DTC methods are simulated and experimentally validated. The dynamic and steady-state torque performance obtained with the proposed CSF-DTC methods for induction motor are compared with the existing DTC methods which show a significant reduction in the steady-state torque and current ripple whereas the torque dynamic performance is almost preserved.