Stator Resistance Estimation Of Modified DTC IM Drives Using Fuzzy Logic

Volume 11 Issue 3 January - March 2018

Research Paper

Stator Resistance Estimation Of Modified DTC IM Drives Using Fuzzy Logic

Naveen Goel*, Ram Narayan Patel**, Saji Chacko***

* Research Scholar, Swami Vivekanand Technical University, Bhilai (C.G.), India.

** Professor, Department of Electrical and Electronics Engineering, Shri Shankaracharya Technical Campus, Bhilai, India.

*** HOD, Department of Electrical, Government Polytechnic College, Durg, Chhattisgarh, India.

Goel, N., Patel, R. N., and Chacko, S. (2018). Stator Resistance Estimation Of Modified DTC IM Drives Using Fuzzy Logic. i-manager’s Journal on Electrical Engineering, 11(3), 34-44. https://doi.org/10.26634/jee.11.3.14125

Abstract

The electric drives used in industries have adjustable speed drives, where AC Induction motors are used in most of these drives. Due to their low cost, reliability, and performance, they find application in a variety of domains. A number of techniques are reported in the literature for control of induction motor drive. Amongst them, the most advanced and popular technology is the Direct Torque Control (DTC) drive. The control strategy of DTC Induction motor drive requires estimation of torque and flux. The estimation of flux depends on stator resistance (Rs). During drive operation, the motor temperature increases. With increase in motor temperature, the Rs increases and it is found that the change in Rs is normally in between 0.75 to 1.7 times to its normal value. This leads to erroneous flux estimation leading to high flux and torque ripple. Therefore, an online estimation of Rs is required for robust performance of DTC drive. In this paper, the estimation of Rs based on the variation of stator current is proposed. The estimation is based on model reference adaptive system with the adaptive mechanism using the Proportional Integral (PI) and Fuzzy Logic Controller (FLC). The performance of the DTC drive using the two different adaptive mechanisms is compared and the results obtained show improved performance in terms of motor speed, torque, and flux developed despite changes in Rs .