Báo Cáo Sensorless speed estimation of induction motor in a direct torque control system

Sensorless speed estimation of induction motor in a direct torque control system

Fast and robust torque control in a very wide range of speed is very needed by various
industrial AC drive applications. Therefore, since 1986 [1], direct torque control has been
introduced to satisfy this desire. In order to achieve more economical control, conventional
speed sensor has been replacing by sensorless speed estimation. The sensorless schemes are
used so that improving reliability and decreasing maintenance requirements. In this paper,
concerned sensorless techniques of induction machine that is controlled by
(DTC) algorithm are the open-loop estimators and MRAS schemes [2], [3]. To demonstrate
clearly the advantages and disadvantages between two kinds of sensorless techniques,
obtained simulation results are compared. By enhancing speed estimation, the pure integrator
is replace by a low-pass filter to avoid DC drift and saturation problems [2].