TRANSFORMER WITH SHIELDING RINGS IN WINDINGS

摘要

The invention relates to the shielding of windings of a transformer, in particular to a coil and electric shielding arrangement for a transformer, a transformer with the arrangement and a method of manufacturing a coil and electric shielding arrangement for a transformer. A coil and electric shielding arrangement (200) for a dry-type transformer is provided, wherein an electric shielding device (120, 204) is arranged at a distance (D1, D2) to a winding (103, 202) at an axial end (116, 118) of the winding (103, 202) perpendicular to a longitudinal axis (A) of the transformer and parallel to the top surface of a cylindrical-shaped coil which is wound by the winding (103, 202) around the axis (A) such that the electric shielding device (120, 204) covers the cross-section area of the winding (103, 202) perpendicular to the longitudinal axis (A). Another such electric shielding device (120, 204) may be arranged at the other axial end of the winding (103, 202). An insulation material (201) is attached to the winding (103, 202) and to the electric shielding device (120, 204) providing the distance (D1, D2) between the winding (103, 202) and the electric shielding device (120, 204) along the longitudinal axis (A) such that an environment of the winding (103, 202) is shielded against the electric field of the winding (103, 202). The winding (103, 202) and the electric shielding device (120, 204) are casted in a block which insulates the electric shielding device (120, 204) from the electric field of the winding (103, 202) by providing a distance between the winding (103, 202) and the electric shielding device (120, 204).