Patent ID: 9099238
Filing Date: 2015-08-04
Classification: H01F

Abstract:
1. An insulation system for a winding structure, the insulation system comprising: an innermost barrier pair arranged to cover a majority of the winding structure in the axial direction of the winding structure inside and outside the barrier structure relative the curvature of winding turns of windings of the winding structure, wherein at least one barrier of the innermost barrier pair defines a first flow path allowing flow of a dielectric fluid mainly in a first axial direction between the winding structure and the at least one barrier of the innermost barrier pair when the insulation system is in a assembled state, and a first outer barrier arranged radially inwards or radially outwards relative each barrier of the innermost barrier pair, wherein the first outer barrier defines a second flow path, parallel to the first flow path, allowing flow of a dielectric fluid mainly in a second axial direction opposite the first axial direction, a second outer barrier arranged radially inwards or radially outwards from the first outer barrier, wherein the second outer barrier has a surface defining a third flow path for the dielectric fluid, wherein at least one of the barriers of the innermost barrier pair is arranged to provide fluid communication between a first flow path and the second flow path, and the first outer barrier is arranged to provide fluid communication between the second flow path and the third flow path such that dielectric fluid flowing through the insulation system has axial components in the first axial direction in the first flow path and the third flow path and axial components in the second axial direction in the second flow path, wherein the insulating system is arranged such that a dielectric medium is able to flow from the second flow path and enter the first flow path at one axial end portion of one of the barriers of the innermost barrier pair and at the other axial end portion of one of the barriers of the innermost barrier pair exit the corresponding first flow path, wherein each barrier of the innermost barrier pair has a contiguous envelope surface extending between the one axial end portion and the other axial end portion of each barrier of the innermost barrier pair.