Study on a sliding mode variable structure vector control of induction motor drives

Compared with the conventional control strategy of IM. FOC can offer the excellent performance as DC motors. However, the control performance of the resulting linear system depends critically on very accurate coordinate transformations and flux angle estimation. In this paper, an indirect field-oriented induction motor drive with a sliding-mode controller is presented. The design includes rotor speed estimation from measured stator terminal voltages and currents. The estimated speed is used as feedback in an indirect vector control system achieving the speed control without the use of shaft mouted transducers. Stability analysis based on Lyapunov theory is also presented, to guarantee the closed loop stability. The simulation experimental waveforms and results are given.