Rapid switching type superconducting current-limiting transformer and working method thereof

Abstract

The invention discloses a high-speed switch type superconducting current-limiting transformer and a working method thereof. The superconducting current-limiting transformer comprises a low-temperature Dewar, a high-voltage winding, a low-voltage winding, a leading-out terminal of a superconducting winding, a first high-speed switch, a second high-speed switch and a third high-speed switch, the high-voltage winding and the low-voltage winding are soaked in the cooling liquid in the low-temperature Dewar flask and are led out through the lead-out taps; each phase of the low-voltage winding is divided into a main through-flow winding and a main current-limiting winding, the main through-flow winding is connected in series with a first high-speed switch through a leading-out tap, the main current-limiting winding is connected in series with a second high-speed switch through a leading-out tap, and the main through-flow winding and a branch where the main current-limiting winding is located are connected in parallel; the low-voltage winding is provided with a group of mutually insulated leading-out terminals at intervals; and the third quick switch is arranged in an upper gas area of the Dewar and is connected with a leading-out terminal or a neutral gear of the low-voltage winding. Under a short-circuit fault, the length of the superconducting tape cut off when the first quick switch is switched off is changed through the action of the third quick switch, the current-limiting impedance of the superconducting winding is increased, and variable-impedance current limiting is realized.

Description

technical field [0001] The invention relates to the technical fields of superconducting technology, transformer technology and switching appliances, in particular to a superconducting transformer device that uses fast switching to change the winding topology of a superconducting transformer to realize voltage transformation and multi-topology variable impedance current limiting. Background technique [0002] With the continuous development of the economy, the demand for electricity continues to increase, the scale of the power grid is also increasing, the requirements for transmission capacity are also increasing, and the short-circuit current will continue to increase, jeopardizing the security of the system. Superconducting transformers and superconducting current-limiting transformers are based on the zero-resistance characteristics of the superconducting state of superconducting materials and the resistance characteristics of quench time, combined with the current capacit...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the fact that existing superconducting transformers and superconducting current-limiting transformers cannot well realize fault current-limiting functions, the present invention proposes a fast-switching superconducting current-limiting transformer and its working method. The present invention utilizes different connection modes and In the action state, change the topological structure and current-limiting impedance of the superconducting transformer winding, realize the variable impedance current-limiting function, and realize the breaking of the remaining short-circuit current after current-limiting through another fast switch outside the Dewar, and clear the fault of the superconducting current-limiting transformer

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