Novel robust adaptive control for high performance field oriented control drives

The paper presents a robust adaptive speed controller for AC drives. A minimum control synthesis (MCS) algorithm based on model reference adaptive control (MRAC) is employed in the robust controller. This MCS controller requires no prior knowledge of the drive dynamic parameters and is guaranteed to provide global asymptotic stability of the closed loop system. The paper describes many practical aspects of the implementation, such as adaptive gain analysis, adaptive rate selection, the gain variation limits, gain wind-up prevention measure and initial values. The MCS controller has been successfully implemented and outperforms the PI counterpart with respect to speed overshoot in dynamic tracking, torque response and speed recovery when subject to sudden load torque disturbance. The quantitative comparison of various experimental test results for both MCS and PI controllers are shown as support proof. This new MCS controller has considerable potential for industrial applications as is demonstrated in the paper.