Transformer cooling system

Patent metadata

Field	Value
Publication number	US-12394550-B2
Application number	US-202017630252-A
Country	US
Kind code	B2
Filing date	Jul 21, 2020
Priority date	Jul 26, 2019
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A transformer cooling system, includes a dry transformer having a core including 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. The cooling channel is disposed between an inner part of the winding body and an outer part of the winding body. The transformer cooling system further includes a housing for containing the dry transformer. The housing has an inlet portion for receiving air from outside the housing and an outlet portion for expelling air outside the housing. The transformer cooling system further includes 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.

First claim

The invention claimed is:

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.

2. The transformer cooling system of claim 1 , wherein the first flow generating unit is an active flow generating unit working during operation in a sucking mode.

3. The transformer cooling system of claim 1 , further comprising guidance plates arranged for guiding the air coming from the inlet portion along a close proximity of the winding body towards the outlet portion of the dry transformer.

4. The transformer cooling system of claim 1 , wherein the cooling channel is arranged for guiding the air coming from the inlet portion longitudinally through the winding body.

5. The transformer cooling system of claim 1 , wherein the winding body of the dry transformer comprises two winding body segments arranged separately in the longitudinal direction of the leg, wherein segment cooling channels are provided there between.

6. The transformer cooling system of claim 1 , wherein the dry transformer comprises a two-limb transformer core surrounded on both of its limbs by hollow cylindrical winding elements.

7. The transformer cooling system of claim 1 , wherein the inlet and outlet portions are provided on opposite sides of the transformer housing, the opposite sides being spaced apart from each other in the longitudinal direction of the leg.

8. The transformer cooling system of claim 1 , wherein the flow generating device is arranged for generating the under pressure at an upstream side of the outlet portion.

9. The transformer cooling system of claim 1 , wherein the flow generating device is arranged directly upstream of the outlet portion.

10. The transformer cooling system of claim 1 , wherein the dry transformer is a three-phase transformer comprising three legs and three windings.

11. The transformer cooling system of claim 1 , wherein the dry transformer is a traction transformer adapted for feeding a current to an electrical machine.

12. A transformer installation comprising:
a first dry transformer comprising:
a first core comprising:
a first leg;
a first winding body arranged around the first leg;
a first cooling channel extending in a direction of a longitudinal axis of the first winding body, wherein the first cooling channel is disposed between an inner part of the first winding body and an outer part of the first winding body;

a first housing for containing the first dry transformer, the first housing having a first inlet portion for receiving air from outside the housing and a first outlet portion for expelling air outside the first housing;
a flow generating device arranged at the first outlet portion and adapted to generate an under pressure for sucking the air from the first inlet portion towards the flow generating device and to expel the air through the first outlet portion outside the first housing, wherein the flow generating device comprises a first flow generating unit arranged at the first outlet portion to force an air stream to flow from the first inlet portion to the first outlet portion of the first housing through the first cooling channel of the first 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 first cooling channel of the first dry transformer; and
a second dry transformer comprising:
a second core comprising:
a second leg;
a second winding body arranged around the second leg; and
a second cooling channel extending in a direction of a longitudinal axis of the second winding body, wherein the second cooling channel is disposed between an inner part of the second winding body and an outer part of the second winding body;

a second housing for containing the second dry transformer, the second housing having a second inlet portion for receiving air from outside the housing and a second outlet portion for expelling air outside the second housing; and
the flow generating device further arranged at the second outlet portion and adapted to generate an under pressure for sucking the air from the second inlet portion towards the flow generating device and to expel the air through the second outlet portion outside the second housing, wherein the first flow generating unit is further arranged at the second outlet portion to force an air stream to flow from the second inlet portion to the second outlet portion of the second housing through the second cooling channel of the second dry transformer, and wherein the flow generating device further comprises another 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 second cooling channel of the second dry transformer,
wherein the respective first and second housings of the first and second dry transformers are separate from each other; and
wherein the second flow generating units comprise a respective pressure chamber located within and separate from their respective housings, wherein the pressure chamber is connected at one end of the winding body of the first and second dry transformers and connected to the first flow generating unit through at least an outlet tube.

13. A dry transformer comprising:
a housing having an inlet portion for receiving air from outside the housing and an outlet portion for expelling air outside the housing;
a core arranged within the housing;
a winding body arranged around the core;
a cooling channel extending in a direction of a longitudinal axis of the winding body, wherein the cooling channel is disposed within the winding body; and
a flow generating device arranged within the housing 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

Assignees

• Hitachi Energy Ltd

Inventors

• Tepper Jens
• Wang Yong

Classifications

• H01F2027/328

  Dry-type transformer with encapsulated foil winding, e.g. windings coaxially arranged on core legs with spacers for cooling and with three phases · CPC title

• H01F27/2876 Primary

  Cooling (cooling transformers and inductances in general H01F27/08) · CPC title

• H01F27/085

  Cooling by ambient air · CPC title

• H01F38/16

  Cascade transformers, e.g. for use with extra high tension · CPC title

• H01F27/06

  Mounting, supporting or suspending transformers, reactors or choke coils {not being of the signal type} · CPC title