(19)

(11)

EP 0 634 065 A1

(12)

(43) Date of publication: 18.01.1995 Bulletin 1995/03 (21) Application number: 93908222.0 (22) Date of filing: 23.03.1993

(51) International Patent Classification (IPC):  H02P 9/ 12( . ) (86) International application number: PCT/SE1993/000244 (87) International publication number: WO 1993/020614 (14.10.1993 Gazette 1993/25)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI NL PT (30) Priority: 02.04.1992 SE 19920001039 (71) Applicant: ASEA BROWN BOVERI AB S-721 83 Västeras (SE)	(72) Inventor: IVARSSON, Claes S-724 70 Västeras (SE) (74) Representative: Grennberg, Erik Bertil, et al  H. Albihns Patentbyra AB, Box 3137 S-103 62 Stockholm S-103 62 Stockholm (SE)