High performance speed tracking of CSI-fed SCIM drive employing a variable-gain proportional-integral (VGPI) speed controller

Abstract

The conventional PI controller employed in the outer speed control loop for variable speed operation of the induction motor drive suffers from the problem of large overshoot during perturbation in reference speed or during increase/decrease in load condition. In this paper, a variable-gain proportional-integral (VGPI) controller is employed in the outer speed control loop of a current source inverter-fed squirrel cage induction motor drive. The drive performances with VGPI speed controller are evaluated through MATLAB simulation not only for several perturbations in reference speed but also under sudden change in load conditions and are then compared with that employing a conventional PI speed controller. The VGPI speed controller offered overall better speed tracking performance with greatly reduced overshoot.