Graphical DC analysis of three-phase PWM converters using a complex transformation

A graphical complex transformation technique is described for the analysis of balanced three-phase converters in the rotation reference frame. The technique avoids the cumbersome matrix manipulation of the equation form of the complex transformation, and the coupling between the subcircuits resulting from the real (dq) transformation. It uses symmetric and decoupled equivalent circuits to graphically analyze three-phase converters, thus greatly simplifying the analysis procedure. All three-phase circuit components are modeled in the transformed coordinates, where all circuit parameters are constant under steady state. The application of the technique is demonstrated for the boost inverter