Superconducting fault current limiter

Abstract

The invention relates to a superconducting fault current limiter, comprising a current limiting reactor, a resonant capacitor connected with the current limiting reactor in series, an arrester connected with the resonant capacitor in parallel, a high-speed eddy current switch and a smart protection control system. The smart protection control system comprises a bi-directional controlled rectifier which is connected with two ends of the resonant capacitor in parallel, and an inductor connected with the bi-directional controlled rectifier in series. The superconducting fault current limiter is simple in structure and convenient for use and is safe and reliable. The intensity of a short circuit current can be effectively limited, the impact of the short circuit current on an electrical device is greatly reduced, a voltage of a user side is ensured, and moreover, the superconducting fault current limiter has no loss.

Description

technical field [0001] The invention relates to the technical field of current limiting of power distribution equipment in a power system, in particular to a superconducting fault current limiter. Background technique [0002] With the development of the economy and the sharp increase of electrical load, the capacity of the power grid increases, and the impact of the increasing short-circuit current on the electrical equipment of the power system is increasing; at the same time, the breaking capacity of the existing circuit breaker has been difficult to meet Break the huge short-circuit current. Therefore, in order to solve this major problem, the current-limiting reactor is widely used in the transmission and distribution system of the power system by being connected in series. The current-limiting reactor connected in series in the circuit can limit the short-circuit current intensity, reduce the impact of the short-circuit current on the electrical equipment in the power...

AI Technical Summary

Problems solved by technology

However, the series current-limiting reactor has many shortcomings. First, the huge reactive power loss in the series circuit of the current-limiting reactor also causes a great economic burden to the user; secondly, when selecting the reactance value of the current-limiting reactor , there is often a contradiction that the voltage at the user end is too low under the rated current after meeting the requirements for limiting the short-circuit current

In the long-distance transmission process of the transmission and distribution network of the power system, the transmission line will also generate inductive reactance, which is equivalent to forming an invisible and potential reactor in the load circuit of the user in series, which also causes the voltage at the user end to decrease, and at the same time There is also a large reactive power loss

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