Nonlinear Load-Adaptive MIMO Controller for DC Motor Field Weakening

Abstract

Control problem of field weakening for a separately excited DC motor system, modeled in nonlinear differential equations, is tackled in this paper. A novel constant power field weakening controller, based on nonlinear load-adaptive multi-input multi-output (MIMO) linearization technique, is developed to achieve high-performance speed tracking through rejecting load disturbance. The effects of decoupling and linearization permit the controller to be implemented and operated at desired field weakening point of operation. Computer simulations are presented to demonstrate the effectiveness of the proposed controller for a specific motor. It has been shown that the proposed controller provides higher dynamic performance in comparison with traditional PI controllers, whereas the motor system is run over wide dynamic field weakening regimes.