An Effective Method for Rotor Time-Constant and Load Torque Estimation for High Performance Induction Motor Vector Control

Abstract

This paper proposes an adaptive robust vector control based on Backstepping technique. The proposed controller associates Indirect Field Oriented and Backstepping controls in order to reduce the complexity of the dynamic model. A comparative study between two non adaptive vector control methods, namely the conventional Proportional-Integral regulators and Integrated Backstepping technique, will be provided to determine the appropriate approach that will be combined with adaptive laws. The objective of the new controller is to track the rotor speed, maintain the rotor flux at its rated value and on-line update the rotor time- constant and external load torque disturbances. A closed loop sliding mode observer to estimate the rotor flux is employed and the robustness of the suggested algorithm is analyzed. The three phase inverter is controlled by sinusoidal PWM operating at 10 kHz. Simulation results show improved performance of the proposed approach compared to the conventional indirect rotor flux oriented control and accuracy of on-line estimation of rotor time-constant and load torque disturbances.