VECTOR APPROXIMATION METHOD WITH PARAMETER ADAPTATION AND TORQUE CONTROL OF CSI-FED INDUCTION-MOTOR

The concept of the vector approximation method for CSI-fed induction m otors consists of vector control and the shaping of a stator current w ave, Vector approximation means that a desirable space current vector is approximated by two realizable current vectors which have only six directions, and by de link current control, The main purpose of the ve ctor approximation method is not only to decrease torque ripple but al so to control instantaneous torque, which is different from the purpos e of the general PWM method. Moreover, a parameter adaptation system c ontaining a magnetic saturation table and a model reference adaptive s ystem (MRAS) has been added to the system, and this system works at an y constant flux level and the steady state, The simulation and experim ental results show the proposed method bring more precise vector appro ximation and torque control to induction motor drive systems.