Three-phase Current Control by Dynamic Reconstruction of Undetected Currents for AC Motor Drives

This paper proposes new three-phase current control methods for ac motor drives, which detect only a phase current from among three-phase currents. The first proposed method first detects a phase current, and then estimates the two-phase current in the stationary reference frame using the detected single phase current. The second proposed method first detects a phase current, then synthesizes the two-phase quasi-current in the dq rotating reference frame, and finally produces two-phase current estimates by extracting the positive-phase component from the quasi-current. The third proposed method produces two-phase current estimates by filtering out the negative-phase component from the quasi-current. This paper presents the principles and detailed characteristic analyses of the proposed methods and validates them on the basis of extensive experiments.