The Boeing Company
Autotransformer rectifier unit with multiple alternating current level outputs

Abstract:

An electric power system is provided that includes a three-phase to two twelve-phase transformer. The transformer includes first and second primary winding groupings, secondary winding groupings, and third, fourth, and fifth windings. The groupings can include sub windings. First primary winding groupings are coupled to form a wye configuration and coupled to second primary winding groupings and the windings. The first of the two twelve-phase outputs at the same voltage as the input voltage while the second twelve-phase output is at a lower voltage. Diode pairs are connected to each other, each diode pair having an inner connection connected to one of the outputs of the transformer and first and second ends respectively connected to a positive dc bus and a negative dc bus. The diode pairs operatively rectify the transformer output voltage to form a DC voltage with a reduced common mode voltage.