Research on Stator Flux and Rotor Speed Estimation for Induction Motor Based on Extended Complex Kalman Filter

Abstract

This paper proposes a stator flux and rotor speed estimation method for induction motor (IM) based on extended complex Kalman filter (ECKF). A complex-valued model is adopted that allows a simpler and more effective state estimation of IM. And a third order ECKF has been designed for IM model by neglecting the mechanical equation, which is a valid hypothesis when the motor is operated at a constant rotor speed. The stator flux and rotor speed estimation obtained from ECKF are applied for direct torque control (DTC) of induction motor. This method for state estimation is more effective and easier than the one performed on the corresponding real-valued model, as it obtains observability conditions directly in terms of stator current and flux complex-valued vectors. The proposed ECKF achieves a good performance in DTC of IM. Simulation experiment results in Matlab/Simulink environment validate the proposed method.