US 12,394,550 B2
Transformer cooling system
Jens Tepper, Wolfenbüttel (DE); and Yong Wang, Brilon (DE)
Assigned to Hitachi Energy Ltd, Zürich (CH)
Appl. No. 17/630,252
Filed by Hitachi Energy Ltd, Zürich (CH)
PCT Filed Jul. 21, 2020, PCT No. PCT/EP2020/070536
§ 371(c)(1), (2) Date Jan. 26, 2022,
PCT Pub. No. WO2021/018668, PCT Pub. Date Feb. 4, 2021.
Claims priority of application No. 19188662 (EP), filed on Jul. 26, 2019.
Prior Publication US 2022/0285068 A1, Sep. 8, 2022
Int. Cl. H01F 27/02 (2006.01); H01F 27/08 (2006.01); H01F 27/28 (2006.01); H01F 27/32 (2006.01)
CPC H01F 27/025 (2013.01) [H01F 27/085 (2013.01); H01F 27/2876 (2013.01); H01F 2027/328 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A transformer cooling system comprising:
a dry transformer comprising:
a core comprising:
a leg;
a winding body arranged around the leg; and
a cooling channel extending in a direction of a longitudinal axis of the winding body, wherein the cooling channel is disposed between an inner part of the winding body and an outer part of the winding body;
a housing for containing the dry transformer, the housing having an inlet portion for receiving air from outside the housing and an outlet portion for expelling air outside the housing; and
a flow generating device arranged at the outlet portion and adapted to generate an under pressure for sucking the air from the inlet portion towards the flow generating device and to expel the air through the outlet portion outside the housing, wherein the flow generating device comprises a first flow generating unit arranged at the outlet portion to force an air stream to flow from the inlet portion to the outlet portion of the housing through the cooling channel of the dry transformer and a second flow generating unit arranged upstream of the first flow generating unit in the direction of the air stream to create a further under pressure in the cooling channel of the dry transformer;
wherein the second flow generating unit comprises a pressure chamber located within and separate from the housing, wherein the pressure chamber is connected at one end of the winding body of the dry transformer and connected to the first flow generating unit through at least an outlet tube.