A Luenberger State Observer for Simultaneous Estimation of Speed and Stator Resistance in Sensorless IRFOC Induction Motor Drives

This paper characterizes the problem of implementing a simultaneous estimation of the stator resistance and the rotor speed of a sensorless indirect rotor flux oriented control (IRFOC) induction motor (IM) drive. For this purpose, the Luenberger state observer (LSO) is taken as a rudimentary method to simultaneously estimate the rotor speed and the stator resistance. Likewise, we suggest an adaptation algorithm related to the Lyapunov stability hypothesis to estimate the stator resistance and the rotor speed. The latter utilizes the estimated and measured stator currents and the estimated rotor flux. Along these lines, the control method that we suggest is liable to achieve a good performance after reducing the computational complexity through the use of the analytical relation in order to determine the Luenberger observer (LO) gain matrix. Additionally, compared to the previous observers, our observer is characterized by its simplicity, robustness as well as its ability to be implemented online. This article implies also the use of a typical PI regulator with feed-forward reparation expressions in the synchronous frame. But to regulate the rotor speed, we use the IP controller because of its effectiveness. Actually, its validity and efficiency are verified by the simulation results.