US 12,354,767 B2
Condenser bushing
Jan Czyzewski, Cracow (PL); Jedrzej Banaszczyk, Lodz (PL); Darren Tremelling, Apex, NC (US); Andrzej Rybak, Cracow (PL); Krzysztof Kasza, Cracow (PL); Lukasz Matysiak, Cracow (PL); and Elio Perigo, Wendell, NC (US)
Assigned to HITACHI ENERGY LTD
Appl. No. 17/789,969
Filed by Hitachi Energy Ltd, Zürich (CH)
PCT Filed Dec. 22, 2020, PCT No. PCT/EP2020/087675
§ 371(c)(1), (2) Date Jun. 29, 2022,
PCT Pub. No. WO2021/136730, PCT Pub. Date Jul. 8, 2021.
Claims priority of application No. 19220097 (EP), filed on Dec. 30, 2019.
Prior Publication US 2023/0041971 A1, Feb. 9, 2023
Int. Cl. H02G 15/072 (2006.01); H01B 17/58 (2006.01); H01G 4/35 (2006.01); H01B 17/28 (2006.01); H01G 4/32 (2006.01)
CPC H01B 17/583 (2013.01) [H01G 4/35 (2013.01); H02G 15/072 (2013.01); H01B 17/28 (2013.01); H01G 4/32 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A condenser bushing comprising:
a condenser core and electrically conductive field-grading layers, which are embedded in insulating material of the condenser core and arranged around a central channel for a conductor extending along an axis defining an axial direction, an electric connection being provided to at least one of the field-grading layers,
pairs of neighbouring field-grading layers with the insulation material between them forming sections of the condenser core of axial lengths L1 through Ln and with capacitances C1 through Cn,
a shape of at least one of the field-grading layers deviating from cylindricality to reduce non-uniformity of electric field stress of the condenser bushing compared to a corresponding condenser bushing with the cylindrical field-grading layers forming corresponding sections of the axial lengths L1 through Ln and with capacitances C1 through Cn, and
at least one of the field-grading layers being shaped such that the diameter of said field-grading layer varies along the axial direction, the diameter of said field grading layer having at least one maximum between the edges of the field-grading layer, wherein the maximums of the field-grading layers increase in amplitude along a radial direction, but narrower in width along the axial direction, with increasing distance from the condenser core, wherein the terminating ends of each of the field-grading layers are straight in the axial direction.