A magnetic integrated hybrid distribution transformer includes a main transformer, a series isolation transformer and a converter, wherein: an iron core includes an iron beam unit, an iron yoke unit and a leakage magnetic core unit. The main transformer includes secondary windings, primary windings and control windings all of which are layer-windings and wound around main transformer iron beams. The series isolation transformer includes converter side windings and grid side windings all of which are pancake-windings and wound around isolation transformer iron beams. The converter side windings and the control windings are respectively connected with the converter by the star connection with neutral point. Leakage magnetic cores are respectively inserted between the primary windings and the control windings or between the converter side windings and the grid side windings, so as to achieve magnetic integration design of the transformer and output connection inductor of the converter.

A wound core equipped with a laminated body including plural electrical steel sheets stacked in a ring shape in side view. The laminated body includes plural bent portions, and plural block-shaped portions at positions between adjacent bent portions. At least one block-shaped portion among the plural block-shaped portions includes a heat transmission path bordered by the electrical steel sheets at least at a portion between the stacked electrical steel sheets. The heat transmission path is included only at the at least one block-shaped portion.

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves and includes two or more broken lines including the grooves having a length of 5 to 10 mm on a straight line intersecting a rolling direction on the steel sheet surface. In each of the broken lines including the grooves, the grooves are arranged at equal intervals, and a ratio of the length of the groove to a length of a non-groove is in a range of 1:1 to 1.5:1.

An iron core (1, 11, 31) for a stationary induction apparatus according to one embodiment is configured by laminating a plurality of electromagnetic steel plates (5, 16, 33). The electromagnetic steel plates are laminated so that joint parts (6, 17, 18, 32), at which the end portions of the electromagnetic steel plates abut one another, are disposed in a staggered manner; and the electromagnetic steel plates are provided with a magnetic domain fine differentiation processed part (7, 19, 34), which is located on the portion, of a surface of the end portion of each of the electromagnetic steel plates, lapped with the joint part of another electromagnetic steel plate, and which has been subjected to warping-derived magnetic domain fine differentiation.

A grain-oriented electrical steel sheet includes a plurality of linear deformable portions formed on a surface of the electrical steel sheet in a rolling direction, wherein an interval between the deformable portions changes to correspond to a grain size of grains over the entire length of the steel sheet, and at least two regions in which intervals between the deformable portions are different exist.

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes producing a cold-rolled plate; forming a groove in the cold-rolled plate; performing primary recrystallization annealing to the cold-rolled plate; and applying an annealing separator to the primary-recrystallized cold-rolled plate and performing secondary recrystallization annealing, wherein a weight ratio of SiO.sub.2/Fe.sub.xSiO.sub.y of the surface layer part of the cold-rolled plate is 0.3 to 3 after the primary recrystallization annealing of the cold-rolled plate. (Here, x is an integer from 1 to 2, and y is an integer from 2 to 4.)

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: manufacturing a cold-rolled sheet; forming a groove in the cold-rolled sheet; removing an Fe—O oxide formed on a surface of the cold-rolled sheet; primary recrystallization annealing the cold-rolled sheet; and applying an annealing separating agent to the primary recrystallized cold-rolled sheet, and secondary recrystallization annealing it, wherein a close contacting property coefficient calculated by Formula 1 below is 0.016 to 1.13.

close contacting property coefficient (S.sub.ad)=(0.8×R)/H.sub.hill-up  [Formula 1] (In Formula 1, R represents the average roughness (μm) of the surface of the cold-rolled sheet after the removing of the oxide, and H.sub.hill-up represents the average height (μm) of the hill-up present on the surface of the cold-rolled sheet after the removing of the oxide.)

Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected region is 90% or more.

One object is to lessen the difference between the direction of the magnetic flux and the easy direction of magnetization in a coil element and improve the effective permeability of the coil element. A coil element according to one element of the present invention includes: a coil conductor wound around a coil axis; at least one isotropic magnetic material layer provided on at least one of an upper surface and a lower surface of the coil conductor, the at least one isotropic magnetic material layer being made of an isotropic magnetic material; and at least one anisotropic magnetic material layer provided on an opposite surface of the at least one isotropic magnetic material layer to the coil conductor, the at least one anisotropic magnetic material layer being made of an anisotropic magnetic material having an easy direction of magnetization oriented perpendicular to the coil axis.

Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected region is 90% or more.