Method for enhancing fault current resistance of three-phase coaxial superconducting cable

Abstract

The invention discloses a method for enhancing the fault current resistance of a three-phase coaxial superconducting cable, and the method comprises: enabling a three-phase coaxial superconducting cable branch and a conventional wire branch to be connected to a bus in parallel, and enabling three phases of the conventional wire branch and three phases of the superconducting cable branch to be connected in parallel. By applying the method provided by the invention, when the superconducting cable branch breaks down, the short-circuit current exceeds the critical current of the superconducting cable, the superconducting cable is rapidly quenched, and the superconducting cable is in a high resistance state. At the moment, the impedance of the bypass conventional wire branch is smaller than theimpedance of the superconducting cable branch, thereby achieving a shunting effect, greatly reducing the fault current passing through the superconducting cable branch, improving the fault current tolerance level of a superconducting cable system, and protecting the safety of a superconducting power-on conductor. Compared with a conventional reactor connected in series, the system loss under thenormal operation condition is greatly reduced; and compared with the use of a superconducting current limiter, the cost is lower, and the coordination is simple.

Description

Technical field [0001] The invention relates to the technical field of superconducting cables, and more specifically, to a method for enhancing the anti-fault current capability of a three-coaxial superconducting cable. Background technique [0002] High-temperature superconducting cables have many advantages, such as low line loss, large transmission capacity, small corridors, and environmental friendliness. They provide an efficient, compact, reliable and green power transmission method for the power grid. After more than ten years of development, superconducting cables have made tremendous progress in basic research. Considering many factors such as the continuous growth of power energy demand and the rapid increase in the proportion of new energy sources, the superconducting power transmission technology that can simultaneously achieve high-efficiency, low-loss and large-capacity power transmission will play a greater role in the future, and its application prospects are very...

AI Technical Summary

Problems solved by technology

However, series conventional reactors cause system losses under normal operating conditions and degrade voltage quality

However, the use of superconducting current limiters has problems such as high cost and complicated coordination of relay protection.

[0005] To sum up, how to effectively solve the problems such as the weak anti-fault current capability of the three-phase coaxial superconducting cable itself is a problem that those skilled in the art need to solve

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