Title: Improving Speed Control of Induction Motor Using Pulse Width Modulation Technique Based PI Controller
Authors: Moses Ejiofor Okafor and Chidiebere Okafor
Volume: 8
Issue: 8
Pages: 49-55
Publication Date: 2024/08/28
Abstract:
This paper presents a Pulse Width Modulation (PWM) control based proportional and integral (PI) control technique for improving speed control of induction motor. It is required to improve the speed control of induction motor to overcome the effect of oscillation of speed and high overshoot due to parameter variations induced by the use of conventional control technique such as PI controller. In order to do this, the mathematic equations that described the dynamic characteristics of induction motor were obtained. Then a PWM controller that combines PI control scheme was designed in MATLAB/Simulink environment. The designed control strategy was integrated into the closed loop speed control system of induction motor. Simulations were performed by considering different simulation time interval from 0.5 second to 1.5 seconds representing various transient response time of the speed control of the motor. The simulation results obtained showed that the overall speed performance of induction motor seemed to improve as the simulation time increases from t = 0.5 second to t = 1.5 seconds. Thus, at t = 0.5 second, result showed that rotor speed (operational speed) was 892 rpm and at t = 1.5 second, the desired or expected operational speed of 1500 rpm was achieved by PWM-PI controlled induction motor. A comparative study of the PWM-PI controller and PI controller showed that the proposed PWM-PI controller offered the expected rotor speed of 1500 rpm with 0.32% overshoot, while PI controller achieved rotor speed of 1497 rpm with 0.55% overshoot in terms of performance and robustness. The performance is maintained under rotor resistance variations, which is known to cause performance deterioration in vector-controlled induction motors.