The Furukawa Electric Co., Ltd.

International Superconductivity Technology Center

Tokui Yonemura

Masashi Yagi

Shinichi Mukoyama

Tomoya Nomura

Takaharu Mitsuhashi

Jun Teng

Hirao Hirata

Taro Matsuoka

Takao Nakano

Takeshi Yanagisawa

A cryogenic cable termination connector having a small heat inflow from the outside and stable electrical insulation properties. The cryogenic cable termination connector includes a lead-out conductor led out from a site at a very low temperature to a site at room temperature via a liquid refrigerant layer, a refrigerant gas layer, and an oil layer. The lead-out conductor includes a capacitor-cone insulator in which plural metal foils for dividing an electric field from a high voltage level down to the ground voltage level are stacked through an insulator. Among electric field tilting portions in which voltage changes gradually from the high voltage level to the ground voltage level, an electric field tilting portion positioned at a lower part is located in the liquid refrigerant layer and an electric field tilting portion positioned at an upper part is located in the oil layer.

Cryogenic cable termination connector

In a superconducting cable line in which a superconducting cable is connected to a terminal connecting part or an intermediate connecting part, an offset part in which a superconducting cable is laid in a curved-shape is provided near the terminal connecting part or the intermediate connecting part. Further, when it is assumed that the superconducting cable is movable in the offset part, an external tube of the superconducting cable is fixed such that a maximum amplitude part which maximizes the amount of movement of the superconducting cable following thermal expansion and contraction of a cable core becomes immovable.

Superconducting cable line

A terminal connecting part has: a low temperature container filled with a cooling medium; a conductor current lead which has one end immersed in the cooling medium and the other end led to a normal temperature part; and a conductor movable connecting terminal which electrically connects a superconductive conductor layer and the conductor current lead of a superconducting cable. The superconductive conductor layer of the superconducting cable stripped stepwise from a front end is connected to the conductor current lead through the conductor movable connecting terminal. The cable core of the superconducting cable is movable in a longitudinal direction and is rotatable in a circumferential direction while maintaining electrical connection between the superconductive conductor layer and the conductor current lead. The cable core is horizontally supported in the low temperature container.

Terminal connecting part of superconducting cable

A fixation structure for fixing a superconducting cable including a cable core and a thermal insulation tube. The fixation structure includes a fixation box connected to the thermal insulation tube, including a hollow thermal insulation structure, and through which the cable core is passed, a fixation body for fixing the cable core on the inner wall of the fixation box, and a diameter-expanded reinforcement layer that is an electrical insulation layer that has a diameter decreasing toward both ends and is formed on the cable core. A refrigerant flows through the inside of the inner wall of the fixation box. The cable core is fixed on the inner wall with the fixation body through the diameter-expanded reinforcement layer. The structure implements a simple and low-cost fixation structure appropriate for an electric field design.

Fixation structure of superconducting cable and fixation structure of superconducting cable line

An AC superconducting cable with an insulating layer on the external circumference of a conductor, and wherein: the insulating layer includes a first insulating layer, a second insulating layer and a third insulating layer, from the inside layer to the outside layer; the insulating layer is impregnated with liquid nitrogen; the product of the dielectric constant &#x2208;of the first insulating layer and the dielectric loss tangent tan &#x3b4;and the product of the dielectric constant &#x2208;of the second insulating layer and the dielectric loss tangent tan &#x3b4;fulfilling the relationship &#x2208;&#xd7;tan &#x3b4;&#xd7;tan &#x3b4;; and the product of the dielectric constant &#x2208;of the second insulating layer and the dielectric loss tangent tan &#x3b4;and the product of the dielectric constant &#x2208;of the third insulating layer and the dielectric loss tangent tan &#x3b4;fulfilling the relationship &#x2208;&#xd7;tan &#x3b4;&#xd7;tan &#x3b4;

Superconducting cable

In a terminal structure of a superconducting cable conductor, a terminal portion of the superconducting cable conductor is connected with a terminal member of a good conductor. The terminal portion includes a superconducting layer disposed on an outer periphery of a central support; and an insulating layer surrounding the superconducting layer. The insulating layer and the superconducting layer are partially removed to expose the central support and the superconducting layer in this order from an end of the superconducting cable conductor. The terminal member includes a metal sleeve which includes a first cylindrical portion whose inner surface is in close contact with an exposed portion of the central support; a second cylindrical portion which is soldered around an exposed portion of the superconducting layer; and a third cylindrical portion into which the insulating layer is inserted.

Terminal structure of superconducting cable conductor and terminal member used therein

An organic composite insulator (tube) and method for production thereof giving an external flashover characteristic, enabling a reduction of the cost, and enabling a reduction of the size of the insulator. The outside diameters of the insulator sheath body and watersheds at only the intermediate insulator sheath ( ) corresponding to the vicinity of the tip ( ) of the top of the inside electrode ( ) are made larger than the outside diameters of the body and watersheds of the upper and lower insulator sheaths ( ) and ( ). The electric field of the sheath surface in the vicinity of the tip ( ) of the top of the inside electrode ( ) exhibiting the maximum electric field in the large size insulator is weakened and the maximum electric field part is moved to the top portion of the sheath body and watersheds enlarged in inside diameter. Further, the insulator act to block the propagation of the air dielectric breakdown occurring at the maximum electric field part to the ground side end fitting ( ) and thereby to increase the external flashover voltage.

Growing community of inventors

Chiba, Japan

Tokui Yonemura