Comparison of selected 3-phase switched mode rectifiers

Prominent members of the large variety of 3-phase switched mode rectifiers constrained to unidirectional power flow are inspected and compared with respect to criteria: power losses and density, THD (total harmonic distortion) and count of semiconductors. Derivatives of the standard switched mode boost-type rectifier bridge topology such as a 6-pulse diode bridge, employing parallel-connected subtopologies, and a 3-level topology are taken into account. Stress quantities are derived for the analytical calculation of conduction and switching losses, measures for the loss and THD minimization are discussed using conventional or flat-top modulation in order to facilitate a solid based selection. Identifying the input filters as the major cost block leads to a 3-level SMR as being the optimum topology with a high potential degree of optimization.