Abstract: A current damper for a voltage transformer, including a first section includes at least one pair of diodes arranged in an anti-parallel configuration; a second section arranged parallel to the first section, and including at least one capacitor; and the first section and the second section being configured to be coupled between a neutral connection of the voltage transformer and a ground potential. A system for current damping includes a plurality of current dampers. A medium voltage or high voltage transformer includes a current damper, a medium voltage or high voltage switchgear including a current damper, and/or a medium voltage or high voltage switchgear including a medium voltage or high voltage transformer.

Abstract: A transformer core assembly is provided that comprises a first yoke clamping plate for clamping a first yoke of a transformer core, and a second yoke clamping plate for clamping a second yoke of the transformer core. Further, the transformer core assembly comprises a plurality of stacked sheets forming a tie plate. The tie plate has a first end and a second end, wherein the first end is connected to the first yoke clamping plate and the second end is connected to the second yoke clamping plate. Using stacked sheets for forming the tie plate significantly improves the availability of a suited material for manufacturing the tie plate. For example, there is a class of high manganese steel material having an adequate, high tensile strength.

Abstract: Provided is a DC current damper for a medium voltage or high voltage transformer. The DC current damper includes at least one pair of diodes. The two diodes in each pair of diodes are in an anti-parallel configuration. The at least one pair of diodes is configured to be connected between a neutral connection of a medium voltage or high voltage transformer and ground potential.

Abstract: Provided is a DC current damper for a medium voltage or high voltage transformer. The DC current damper includes at least one pair of diodes. The two diodes in each pair of diodes are in an anti-parallel configuration. The at least one pair of diodes is configured to be connected between a neutral connection of a medium voltage or high voltage transformer and ground potential.

Abstract: Exemplary embodiments include a fluid insulated high voltage coil having closed tank for an insulation fluid and a high voltage coil arranged therein with at least two taps. An insulation tube extends into the tank, where the inner part of the tube is accessible from an outer side of the tank. Electric contact elements extend through the tube walls along its longitudinal axis, where at least some of the contact elements are electrically connected with the taps. A removable column-like electrical interaction device is arranged within the inner part of the insulation tube, which is electrically connected to the at least two taps by means of the contact elements.

Abstract: Exemplary embodiments include a fluid insulated high voltage coil having closed tank for an insulation fluid and a high voltage coil arranged therein with at least two taps. An insulation tube extends into the tank, where the inner part of the tube is accessible from an outer side of the tank. Electric contact elements extend through the tube walls along its longitudinal axis, where at least some of the contact elements are electrically connected with the taps. A removable column-like electrical interaction device is arranged within the inner part of the insulation tube, which is electrically connected to the at least two taps by means of the contact elements.

Abstract: An elongated current limiting composite material comprising one or more high-temperature superconductor filaments and a second electrically conductive member, which may include a sheath of high bulk resistivity surrounding the filament. The current limiter exhibits dissipation in the range of 0.05-0.5 V/cm at currents of 3-10 times the operating current, thereby minimizing fault currents and improving recovery capability.

Abstract: A superconducting conductor and its method of manufacture includes an electrical conductor having a thermal conductor attached to and along a length of superconductor member and separated from the superconductor member by an electrically-insulative material. The member may include a length of superconductor composite having superconducting material and a non-superconducting, electrically conductive matrix material. The electrical conductor is configured to control the manner in which the superconductor transitions from its superconducting state to its non-superconducting (i.e., normal) state due to, for example, a fault current condition. The electrically-insulative material has a thickness for allowing heat from the superconductor to be conveyed to the thermal conductor. The superconducting conductor may be used in conjunction with a superconducting current-limiting device.

Abstract: A superconducting conductor and its method of manufacture includes an electrical conductor having a thermal conductor attached to and along a length of superconductor member and separated from the superconductor member by an electrically-insulative material. The member may include a length of superconductor composite having superconducting material and a non-superconducting, electrically conductive matrix material. The electrical conductor is configured to control the manner in which the superconductor transitions from its superconducting state to its non-superconducting (i.e., normal) state due to, for example, a fault current condition. The electrically-insulative material has a thickness for allowing heat from the superconductor to be conveyed to the thermal conductor. The superconducting conductor may be used in conjunction with a superconducting current-limiting device.

Abstract: In a current limiting arrangement based on a superconducting transformer (30), a load (21) can be supplied with power without any interruption by providing an auxiliary winding (14) in parallel with the superconducting primary winding (12) of the transformer (30). This auxiliary winding (14) carries the excess current in the event of a short circuit and allows the superconducting primary winding (12), which has been heated due to the current limiting, to cool down. Once the short circuit has been cleared, the latter winding can once again carry the rated current, without any losses, immediately. The auxiliary winding (14) is composed of a normally conductive material and has an additional stray impedance.

Abstract: A cryostat for a superconducting transformer is provided that includes non-conducting load bearing insulation and is adapted for use with a superconducting transformer. In addition, the cryostat prevents the formation of closed loop stray currents on its outer case. The cryostat contains the winding sets and other related electrical equipment of a transformer. The cryostat generally comprises a cryogenic tank having an outer wall, a non-conducting liner, and a load bearing insulation layer disposed therebetween. The tank holds a liquid or gaseous cryogenic coolant into which the components of the transformer are immersed. A plurality of passages allow the passage of the limbs of the iron core of the transformer through the tank.

Abstract: A connection arrangement between superconducting strands of a winding located in a cryotank with strands located external thereof is disclosed. Current leads inside the cryotank are mutually insulated by spacers and current leads outside the cryotank are grouped and interconnected into corresponding single current leads.

Abstract: A cooling device for cooling of current leads (6, 7) in the bushings of a cryotank (1), wherein the current leads in the gas-filled part of the cryotank are designed as plate-formed sub-leads (12) surrounded by a casing (8) of insulating material with an inner open part of rectangular shape. Between all the sub-leads inside the cryotank there are arranged a number of rows of inclined transverse ribs (13a, 13b, . . . 13n, 14a, 14b . . . 14n) of insulating material. On the inner walls of the casing, facing the plate edges of the sub-leads, and at the ends of the transverse ribs, shelves (15, 16) are fixed whereby spiral cooling coils are formed around the current leads from the lower edge of the casing.