ON-LINE IDENTIFICATION OF STATOR RESISTANCE FOR SENSORLESS VECTOR CONTROL SYSTEM OF INDUCTION MOTORS
CHEN Shuo, TSUJI Mineo, YAMADA Eiji (1. Dept. of Mech. Eng., Fuzhou University, Fuzhou 350002, China; 2. Dept. of Elec. & Elec. Eng., Nagasaki University, Nagasaki 852-8521, Japan)
This paper presents an on-line identification algorithm of stator resistance for a speed sensorless vector control system of general-purpose induction motors. The proposed system is based on the observer theory and the adaptive control theories. Since the q-axis estimated rotor flux is used for speed estimation, it must converge to zero by proportional plus integral (PI) regulator. The d-axis flux error between the adjustable model and the reference model is considered to be caused by the stator resistance variation mainly. The relationship between this error and the stator resistance variation is analyzed at a steady state. A very simple on-line identification algorithm using the d-axis flux error for stator resistance is proposed. The advantages of the proposed algorithm are simplicity and solution of the problems of system stability and speed control accuracy under the influence of stator resistance variation when using only a voltage model, especially in low-speed operation. The necessity of the stator resistance identification and the effectiveness of the proposed algorithm have been verified by digital simulation and experimentation.