Performances of fuzzy-logic-based indirect vector control for induction motor drive

This paper presents a novel speed control scheme of an induction motor (IM) using fuzzy-logic control. The fuzzy-logic controller (FLC) is based on the indirect vector control. The fuzzy-logic speed controller is employed in the outer loop. The complete vector control scheme of the IM drive incorporating the FLC is experimentally implemented using a digital signal processor board DS-1102 for the laboratory 1-hp squirrel-cage IM. The performances of the proposed FLC-based IM drive are investigated and compared to those obtained from the conventional proportional-integral (PI) controller-based drive both theoretically and experimentally at different dynamic operating conditions such as sudden change in command speed, step change in load, etc. The comparative experimental results show that the FLC is more robust and, hence, found to be a suitable replacement of the conventional PI controller for the high-performance industrial drive applications.

I. Introduction

AC motor drives are used in a multitude of industrial and process applications requiring high performances. In high-performance drive systems, the motor speed should closely follow a specified reference trajectory regardless of any load disturbances, parameter variations, and model uncertainties. In order to achieve high performance, field-oriented control of induction motor (IM) drive is employed [1]. However, the controller design of such a system plays a crucial role in system performance. The decoupling characteristics of vector-controlled IM are adversely affected by the parameter changes in the motor.