18-Pulse Rectifier with Electronic Phase Shifting and Pulse Width Modulation

At present, 12-pulse rectifiers with electronic phase shift are known. Unlike classic rectifiers, they do not use phase-shifting transformers and have a unit power factor. Increasing of the rectifier's pulse makes it possible to improve the harmonic composition of the input current. This article is devoted to the study of the operation of an 18-pulse rectifier with an electronic phase shift. The use of the principle of electronic phase shift leads to different levels of constant voltage at the output of the rectifiers. The introduction of pulse-width modulation contributes to equalizing the output voltages of the 6-pulse rectifiers which are the parts of the converter. In addition, the use of the pulse-width modulation allows eliminating matching magnetic elements which are used to equalize rectifiers output voltages. This improves the mass and dimension parameters of the converter. The results of modeling are presented.