Development of H-Infinity Based Speed Control of a Sensorless Induction Motor Drives

Abstract

Induction motors (IMs) are widely used in industrial and domestic applications due to their robustness, reliability, and cost-effectiveness; however, achieving accurate and stable speed control under varying load conditions and parameter uncertainties remains a persistent challenge. Conventional scalar and vector control methods rely heavily on mechanical sensors for rotor speed and position estimation, which increase cost, system complexity, and vulnerability to environmental conditions. To overcome these limitations, this study developed an H-infinity based speed control system for sensorless induction motor drives, integrating an Extended Kalman Filter (EKF) for rotor speed estimation with an H-infinity controller to ensure robust and precise control under system uncertainties and disturbances. A dynamic model of a three-phase induction motor was formulated in the d–q reference frame and implemented in MATLAB/Simulink R2021a. The performance of the proposed H-infinity controller was evaluated against a conventional Proportional-Integral (PI) controller using transient response parameters such as rise time, settling time, and percentage overshoot. Simulation results revealed that the H-infinity controller achieved a rise time of 2.42 s, settling time of 5.30 s, and overshoot of 0.82%, outperforming the PI controller, which exhibited 1.83 s, 9.83 s, and 4.49%, respectively, while the uncontrolled system showed an excessive overshoot of 52.79%. The integration of the EKF effectively replaced physical sensors, providing accurate and stable rotor speed estimation even under noise and load fluctuations. The developed H-infinity based sensorless control system demonstrated superior robustness, enhanced transient response, and improved steady-state accuracy compared to conventional control schemes. Consequently, the proposed control approach provides a reliable and energy-efficient solution suitable for industrial automation, electric vehicle propulsion, and renewable energy applications, where adaptability, precision, and robustness are essential.