This study describes a software-based conrol methodology eliminating low-frequency harmonics from a 3.phi. phase-controlled converter. The converter topology used in the study is capable of the phase current lagging and dealying with respect to the phase voltage. Low order harmonics are eliminated in the dc output voltage by introducing notches. The good agreements between the simulation and experimental resuls show the validity of the proposed scheme. The use of the software-based control scheme results in a simple and flexible realization of the system.