A discrete-time variable structure controller for induction motor drives

A discrete time variable structure control is proposed for implementing an induction motor drive system. Constant equivalent control gain and constant switching control gain are obtained to minimize the computations involved in implementation. Moreover, the chattering phenomenon is eliminated to achieve more smooth and stable control. For integration of the whole system, a simple vector control algorithm is also derived to coordinate with the proposed control. It turns out that it is now possible to use a simple 8 bit microcomputer to implement a high performance induction motor drive.