(19)

(11)

EP 1 794 873 A1

(12)

(43) Date of publication: 13.06.2007 Bulletin 2007/24 (21) Application number: 05776425.0 (22) Date of filing: 30.08.2005

(51) International Patent Classification (IPC):  H02M 1/12(2006.01) (86) International application number: PCT/SE2005/001250 (87) International publication number: WO 2006/025782 (09.03.2006 Gazette 2006/10)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (30) Priority: 31.08.2004 SE 0402106 (71) Applicant: ABB Technology Ltd 8050 Zürich (CH)	(72) Inventors: SILJESTRÖM, Roland S-77250 Grängesberg (SE) JIANG-HÄFNER, Ying S-771 43 Ludvika (SE) DOFNÄS, Lars S-771 42 Ludvika (SE) (74) Representative: Kock, Ina  ABB AB Legal Affairs and Compliance/ Intellectual Property Forskargränd 7 721 78 Västerås 721 78 Västerås (SE)