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 motors consists of vector control and the shaping of a stator current wave. Vector approximation means that a desirable space current vector is approximated by two realizable current vectors which have only six directions, and by DC link current control. The main purpose of the vector approximation method is not only to decrease torque ripple but also to control instantaneous torque, which is different from the purpose of the general PWM method. Moreover, a parameter adaptation system containing a magnetic saturation table and a model reference adaptive system (MRAS) has been added to the system, and this system works at any constant flux level and the steady state. The simulation and experimental results show the proposed method bring more precise vector approximation and torque control to induction motor drive systems