Soft-switching triangular current mode control for three phase two-level converters with power factor control

Abstract

Critical-mode soft-switching techniques for a power converter are described. In one example, a power converter includes a bidirectional converter electrically coupled between an alternating current (AC) power system and a direct current (DC) power system, where the bidirectional converter includes a number of phase legs. The power converter can also include a control system configured, during a portion of a line cycle of the AC power system, to clamp a first phase leg of the converter from switching and operate second and third phase legs of the converter independently in either critical conduction mode (CRM) or in discontinuous conduction mode (DCM).