Sliding-mode variable structure current controller for field oriented controlled linear induction motor drive

In this paper, a strategy for field oriented controlled linear induction motor (LIM) drive system using sliding-mode variable structure current controller is proposed to compensate the uncertainties including the parameter variations. This method is based on a LIM model that considering the end effect and attraction force. The dynamic model of an indirect field oriented LIM drive is derived. Then the sliding-mode variable structure current controller is presented. This scheme uses two sliding-mode controllers to regulate the d-axis and q-axis primary currents respectively, and the thrust force and flux of the LIM can be decoupled effectively in the field oriented mechanism. With the sliding-mode current controller, the mover of the LIM drive possesses not only the advantages of feedforward decoupling such as good transient control performance and perfect decoupling, but also the advantages of siding mode variable structure control such as robustness to parameter variations and good anti-disturbance. The effectiveness of the proposed control scheme is verified by both the simulated and experimental results.