A Hybrid Fuzzy-Lqr Based Speed Controller for Induction Motors

Abstract

Induction motors are now widely utilized in a variety of industrial and household applications due to their benefits, which include simple construction, rugged, high reliability and high efficiency. Despite the benefits, an Induction motor has uncertain and nonlinear characteristics which degrade the performance of controllers. As a result, many controllers fail to smoothly track the speed trajectory. Therefore, appropriate speed controllers are required to attain the required level of performance. In this thesis, the Fuzzy- linear quadratic regulator Control technique is used for the speed control of the Induction motor drive system. The proposed control technique is designed, and its performance evaluated against the linear quadratic regulator and the fuzzy logic controller individually. A set of simulation works have been done using MATLAB/SIMULINK. The simulation results show that linear quadratic regulator alone produces a smooth speed response with better rise time and overshoot but it is aggressive and produces chattering about the desired value. The fuzzy logic, on the other hand, with the better settling time and overshoot but high rise time value when it compared to others it is also unable to completely eliminate disturbance. The proposed Fuzzy-Linear quadratic regulator technique takes the benefits of both linear quadratic regulator and Fuzzy controllers to improve the motor drive system's dynamic behavior and it is more resistant to load perturbations (disturbance). The Fuzzy-Linear quadratic regulator controller reduced the overshoot eliminated the chattering effect and resulted in smooth speed tracking with optimal control force utilization, which is the main objective of this thesis.