| Title |
Sensorless Control of Induction Motors with Simultaneous Estimation of Speed and Rotor Resistance in the Very Low Speed Region |
| Keywords |
유도전동기 ; 순시 토크 제어법 ; 센서리스 속도제어 ; 2차 저항 동시 추정 ; 2차 자속 가변 ; |
| Abstract |
This paper is concerned with a new speed sensorless induction motor scheme which can be successfully applied to at any speed including even zero speed. The proposed method is robust against rotor resistance variations. In addition, simultaneous on-line estimations of speed and rotor resistance are realized based on a feedforward type torque control approach. The rotor flux with a low frequency sinusoidal waveform has been utilized to help the simultaneous estimation for both speed and rotor resistance. The control scheme has no current minor loop to determine voltage references. Since the proposed estimation does not depend on any derivative terms of currents and stator voltages, it offers a good performance at extremely low speed region for sensorless induction motor. Furthermore, the proposed control is simply using motor parameters and stator currents without determining any PI gains for current feedback and any signal injection for the rotor resistance estimation. Finally, both simulation and experimental results are given to show the effectiveness of this method. |