Patent ID: 8395913

Claim:
A device comprising: an autotransformer inter-connecting each phase to a midpoint, wherein the device corrects power factor of a 3-phase power converter; and the autotransformer comprising two transformer legs, or the autotransformer comprises two transformer windings; two diodes connecting each transformer leg to the mid-point, or two diodes connecting each transformer winding to the mid-point; and a plurality of controllable bi-directional switches connecting as closed each transformer leg to the midpoint, or a plurality of controllable bi-directional switches connecting as closed each transformer winding to the midpoint, wherein two controllable bi-directional switches, each connected to a leg of the autotransformer, the autotransformer and the diodes form a five-state switching cell, or two controllable bi-directional switches, each connected to a winding of the autotransformer, the autotransformer and the diodes form a five-state switching cell.