Novel power cable short circuit current limiter

Abstract

The invention discloses a novel power cable short circuit current limiter, which comprises a metal oxide varistor, an iron core, a winding coil, a fast switch and a fast switch controller, wherein the fast switch and the fast switch controller, the iron core and the winding coil, and the metal oxide varistor are in parallel connection; in the case of failure, the iron core and the winding coil are serially connected to the system to generate nonlinear inductance to limit short circuit current; the fast switch is serially connected to the system circuit and on or off of the fast switch is controlled by the fast switch controller; and the metal oxide varistor provides overvoltage support when the fast switch is on and off. The novel power cable short circuit current limiter has the significant effects that a DC bias circuit does not need to be additionally arranged to enable the iron core to achieve saturation, the system has zero loss in a normal working state, only one iron core is needed for single-phase protection for the system, and three iron cores are only needed for three-phase protection. The novel power cable short circuit current limiter has the advantages of simple structure, convenient operation, reliable working and the like.

Description

technical field [0001] The invention relates to a current limiting device, in particular to a novel power cable short-circuit current limiter which can limit the current when a short-circuit fault occurs in an urban power grid during power transmission. Background technique [0002] The transformation of urban power grids. A large number of power cables have been put into use. The development of smart grids and the access of various large-scale power stations have made the current short-circuit current level of urban power grids approach the upper limit of the existing circuit breaker capacity. Most of the power cables are buried underground, and it is very inconvenient to repair the power cables due to short circuit and overcurrent damage. It is particularly important to limit the current of power cables in urban power grids. Such problems are particularly prominent in areas with dense power loads. Conventional technical measures such as busbar segmentation, fixed series ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to propose a new type of power cable short-circuit current limiter in view of the deficiencies in the traditional saturated iron core type superconducting short-circuit current limiter, such as high bias coil requirements, high operating loss, large size and high cost. Design, the short-circuit current limiter not only does not need a DC bias system, but also requires only one iron core for single-phase protection, and only three iron cores for three-phase systems, which greatly reduces the cost, reduces the size of the iron core and the overall weight

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