Superconductive current limiter with composite insulation structure

Abstract

The invention discloses a superconductive current limiter with a composite insulation structure. The superconductive current limiter comprises a superconductive current limiting unit, an inner composite insulating cylinder, an outer composite insulating cylinder and a low-temperature container, wherein the inner composite insulating cylinder coaxially sleeves the superconductive current limiting unit along the axial direction; the low-temperature container coaxially sleeves the external composite insulating cylinder along the axial direction; the superconductive current limiting unit is fixedly connected with the inner composite insulating cylinder through inner insulating supporting pieces, and the low-temperature container is fixedly connected with the outer composite insulating cylinderthrough outer insulating supporting pieces. Through the outer composite insulating cylinder connected with the low-temperature container, and the inner composite insulating cylinder connected with the superconductive current limiting unit, air bubbles generated by the low-temperature container are blocked between the low-temperature container and the outer composite insulating cylinder; bubbles generated by the superconductive current limiting unit are blocked between the superconductive current limiting unit and the inner composite insulating cylinder, so that a radial diffusion path of thebubbles in a liquid nitrogen space is blocked, generation of the bubbles between electrodes is prevented, and the insulating effect of the resistive superconductive current limiter is ensured.

Description

technical field [0001] The invention relates to the field of superconducting technology, in particular to a superconducting current limiter with a composite insulating structure. Background technique [0002] The resistive superconducting current limiter is a power device used to suppress the magnitude of short-circuit fault current in the power grid, and insulation is the first problem that all high-voltage power devices need to solve. The resistive superconducting current limiter is mainly developed based on the superconducting state-normal state transition characteristics of the superconducting strip. When the steady-state operating current is normally transmitted, it is in a superconducting state, and the resistance is close to "zero"; when a short-circuit fault occurs in the power grid When , the superconducting strip automatically turns into a normal state under the action of current, and the resistance quickly becomes the resistance value of a conventional conductor, ...

AI Technical Summary

Problems solved by technology

However, the biggest problem with liquid nitrogen as an insulating medium is that liquid nitrogen at 77K is always in a boiling state, and even if it cools down to about 70K, it is close to a boiling state, resulting in very small thermal disturbances that will cause liquid nitrogen to vaporize and generate bubbles

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