Abstract: A method for administering passivator to a conductor in a power transformer, comprising providing a reservoir of the passivator, wherein the reservoir is provided by adding the passivator to solid insulation prior to impregnating the solid insulation with oil, and wherein the passivator is added to the solid insulation as the solid insulation is applied to a conductor.

Abstract: A method, device and computer program product for determining the change in insulating ability of the insulation provided between two objects of an inductively operating element, where at least one of the objects is a winding. The device includes an analyzing unit, which obtains a first frequency spectrum associated with a frequency response to a signal of varying frequency, where the signal of varying frequency can be applied to a first object of the inductively operating element and the frequency response is obtainable from a second object of the inductively operating element, compares the obtained first frequency spectrum with a second reference frequency spectrum, detects a peak in the obtained first frequency spectrum that does not appear in the second reference frequency spectrum, analyzes the shape of the detected peak, and determines the change in insulating ability based on the analyzed shape.

Abstract: A test body for use in determining moisture content in a laminated insulation of a power transformer by measuring a dielectric frequency response of the test body. The test body has a laminated structure of the same material as the laminated insulation, and has a shape and a size to obtain moisture content characteristics that resembles the moisture content characteristics of the laminated power transformer insulation. The test body further includes electrodes, which are embedded in the laminated structure.

Abstract: A method, device and computer program product for determining the change in insulating ability of the insulation provided between two objects of an inductively operating element, where at least one of the objects is a winding. The device includes an analyzing unit, which obtains a first frequency spectrum associated with a frequency response to a signal of varying frequency, where the signal of varying frequency can be applied to a first object of the inductively operating element and the frequency response is obtainable from a second object of the inductively operating element, compares the obtained first frequency spectrum with a second reference frequency spectrum, detects a peak in the obtained first frequency spectrum that does not appear in the second reference frequency spectrum, analyzes the shape of the detected peak, and determines the change in insulating ability based on the analyzed shape.

Abstract: A method, device and computer program product for determining the change in insulating ability of the insulation provided around a conductor of an inductively operating element, which conductor is wound a number of turns. The device includes a signal generating unit that applies a signal of varying frequency to the conductor and an analyzing unit, which receives a frequency response to the signal from the conductor, compares the received frequency response with a reference frequency response and determines the change in insulating ability based on the comparison.

Abstract: A high voltage corona shield including a body portion including a polymer material.

Abstract: A high voltage bushing including a metal part provided with a resistive layer.

Abstract: A method for administering an additive to oil, wherein a reservoir of the additive is provided in the oil.

Abstract: A winding support body (6, 10) for transformers/reactors with a winding of a tape-formed superconductor (8), wherein the support body consists of a substantially straight, circular-cylindrical tubular body which, on the side where the winding is to be placed and out towards the two ends, is provided with a helical slot with a plane surface with a width equal to the width of the tape. In this way, each turn of the slot around the support body forms a surface which practically constitutes the envelope surface of a straight frustum of a cone. The angle (v) between a generatrix (9) of the envelope surface and the axial center line of the support body increases for each turn out towards the ends of the support body in such a way that the envelope surface at all points coincides with the direction of the magnetic field (FIG. 4 ).