Patent ID: 8488354

Claim:
An AC/DC converter system comprising: an input circuit for connection to a three phase AC source; an isolation transformer comprising a set of primary windings and first and second sets of secondary windings magnetically coupled to the set of primary windings, the first and second sets of secondary windings phase shifted by select amounts from the set of primary windings, the set of primary windings connected to the input circuit; an AC/DC converter comprising first, second and third three phase, six-pulse rectifiers, the first three phase six-pulse rectifier being powered by the first set of secondary windings, the second three phase six-pulse rectifier being powered by the second set of secondary windings, and the third three phase six-pulse rectifier being powered by the input circuit; a current balancing three phase inductor electrically connected between the input circuit and the third three phase six-pulse rectifier, the three phase inductor being matched to the windings of the isolation transformer to balance current flowing into the first, second and third three phase six-pulse rectifiers such that the rms value of the currents flowing into the three six-pulse rectifiers are the same, resulting from the wave-shape and duration of conduction of corresponding diode pairs in each of the three six-pulse rectifiers being the same; and an output circuit for connection between the AC/DC converter and a DC load.