High damped digital current controller based on active resistance for AC machines

Abstract

Due to the simple structure and good disturbance rejection, the proportional-integral (PI) digital current controller with active resistance term feedback (ARTF) has been widely utilized in high-performance ac motor drives such as electric vehicles (EV) powertrain. However, the complexity of discrete-time ac machine model, current performance degradation of the PI controller at high bandwidth condition, and ARTF digital delay effect led to the difficulty of design and tuning of the controller. To address these issues, without employing current prediction mechanism, a novel high damped digital current controller with ARTF is proposed in this article, which can achieve deadbeat dynamic response performance, possess strong disturbance rejection with no overshoot in theory, suppress the ARTF digital delay issue effectively, and own lower parameter sensitivity. The effectiveness of the proposed controller is fully validated through a practical ac machine drive test rig.