US 7,548,439 B2
	Electric power converter for reducing generated high frequency components
Hikaru Meguro, Chiyoda-ku (Japan); Hiroshi Ikarashi, Chiyoda-ku (Japan); Keizo Shimada, Chiyoda-ku (Japan); and Masashi Toyota, Chiyoda-ku (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan)
Filed on Mar. 30, 2005, as Appl. No. 11/92,672.
Prior Publication US 2006/0227583 A1, Oct. 12, 2006
Int. Cl. H02M 1/12 (2006.01); H02M 1/14 (2006.01); H02M 3/335 (2006.01)

U.S. Cl. 363—41  [363/40; 363/17; 363/98; 363/132]

17 Claims

1. An electric power converter for switching a plurality of switching devices connected between an AC line and a DC line operated by respective high frequency pulses outputted from a controller so as to be switched synchronously with the respective pulses and converting electric power from a DC circuit to a multi-phase AC circuit or from said multi-phase AC circuit to said DC circuit, the switching devices being provided corresponding to the phases, wherein a reactor is inserted into each phase of said AC line such that a load system side of each reactor is operatively connected with a terminal of an associated capacitor being connected to a line between the AC circuit and DC circuit so as to form a high frequency filter for absorbing generated high frequency waves, the line connecting the AC circuit and DC circuit so as to bypass the switching devices, and said controller compares output of a plurality of carrier sources with output of a signal wave source and supplies high frequency pulses which are output of said comparison to said switching device, and phases of said plurality of carrier sources have predetermined phase differences so as to reduce a synthetic harmonic current of the line between the AC circuit and DC circuit, wherein each of said plurality of carrier sources comprises a triangular waveform.