Normalized model reference adaptive control applied to high starting torque scalar control scheme for induction motors

Abstract

Recently, a novel high-starting torque scalar control scheme (HST-SCS) for induction motor(s) (IM) emerged. It expands the scalar control application field beyond centrifugal pumps, blowers, and fans, moving, for instance, some conveyor belts with nominal torque loading. This paper proposes a normalized model reference adaptive control (N-MRAC) applied to HST-SCS for IM. First, the proposal extends the MRAC, resulting inn a class of nonlinear systems encompassing the IM dynamical model. It uses a normalized information vector, jointly with a direct control approach, reducing the trial and error adaptive controller tuning. Second, a properly designed N-MRAC is applied to regulate the starting stator current within the variable speed drive under investigation. As a result, the proposed methodology keeps the HST-SCS as a simple control scheme without needing variable observers or parameter estimators and employing tuning information only from the motor nameplate and datasheet. Test bench experiments with a 10 HP motor validate the proposal effectiveness.