Patent ID: 8159841

Claim:
An electrical device comprising: a 2N-pulse rectifier having N inputs and providing a set of output terminals/leads, including at least one negative and one positive output terminal/lead; a transformer subsystem having at least one multiple phase transformer with (a) three input terminals/leads, and (b) N output terminals/leads arranged for electrical connection to respective ones of the N inputs of the 2N-pulse rectifier; and at least one series impedance path coupled to one of the three input terminals/leads of the transformer subsystem and which conducts one phase of three phase currents from a three phase power supply to a connected one of the three input terminals/leads of the transformer subsystem, wherein an impedance of the at least one series impedance path is affected by the frequency of the current flowing through the path and wherein the impedance of the at least one series impedance path at any selected frequency above a third harmonic of a fundamental frequency of the three phase power supply divided by the impedance at the fundamental frequency of the three phase power supply is substantially greater than the selected frequency divided by the fundamental frequency of the power supply.