New Three-Phase Current Control Methods Using Quasi-Current-Error for AC Motor Drives

Abstract

This paper proposes new three-phase current control methods for ac motor drives, which detect only a single phase current out of three-phase currents. The proposed methods first detect one of three-phase currents, then synthesize three-phase or two-phase quasi-current-error in a static manner using the detected single phase current and the current command in the dq rotating reference frame, process the multiphase quasi-current-error by using a dedicated current controller, and finally produce a three-phase voltage command. The three-phase quasi-current-error, the two-phase quasi-current-error in the stationary reference frame, and the two-phase quasi-current-error in the rotating reference frame are processed by a 3×3 “D-controller”, 2×2 “D-controller”, and 2×2 standard current controller, respectively. Although the three multiphase quasi-current-errors and three associated current controllers differ from each other, the same voltage commands are produced. This paper presents the principles and detailed characteristic analyses of the proposed methods and validates them by extensive simulations.