(19)

(11)

EP 3 891 767 A1

(12)

(43) Date of publication: 13.10.2021 Bulletin 2021/41 (21) Application number: 19820817.5 (22) Date of filing: 02.12.2019

(51) International Patent Classification (IPC):  H01F 3/10(2006.01) H02M 1/12(2006.01) H01F 38/02(2006.01) H02M 7/48(2007.01) (52) Cooperative Patent Classification (CPC): H01F 2003/106; H02M 1/126; H01F 3/14; H01F 38/023; H01F 3/10; H01F 2038/026; H02M 7/48 (86) International application number: PCT/FI2019/050860 (87) International publication number: WO 2020/115360 (11.06.2020 Gazette 2020/24)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 04.12.2018 FI 20186042 (71) Applicant: Ensto Oy 06100 Porvoo (FI)	(72) Inventors: VANHALAKKA, Juha 00200 Helsinki (FI) TRINH, Dai 04230 Kerava (FI) (74) Representative: Papula Oy  P.O. Box 981 00101 Helsinki 00101 Helsinki (FI)