Saturated iron-core fault current limiter for alleviating DC impact

Abstract

The invention relates to a saturated core-type fault current limiter capable of relieving a direct-current impact. Each core structure shaped like a Chinese character 'ri' comprises a DC core limb, an AC core limb, a bypass core limb and an AC coil, wherein the DC core limb is in a C-shaped structure; each AC core limb is in an I-shaped structure, and is distributed in the middle of the corresponding core structure shaped like the Chinese character 'ri'; each bypass core limb is in the I-shaped structure and is distributed at one end of the outer side of the corresponding core structure shaped like the Chinese character 'ri'; each AC coil is wound on the corresponding AC core limb; two core structures shaped like the Chinese character 'ri' are in transverse mirror-image parallel placement; a DC coil is wound on the peripheries of two adjacent DC core limbs; the AC coils wound on the two AC core limbs are the same in number of turns and consistent in winding direction; the same ends of the AC coils are connected with each other; and the other ends are connected to a power grid in series. The saturated core-type fault current limiter provided by the invention is not only suitable for a single-phase saturated core-type fault current limiter, but also suitable for a three-phase saturated core-type fault current limiter, and is simple in structure, easy to achieve, low in cost and high in reliability.

Description

technical field [0001] The invention relates to a power system short-circuit fault current limiting technology applied to an AC power transmission system, in particular to a device for alleviating the voltage impact effect generated on a DC winding of a saturated iron-core type fault current limiter during the current limiting stage. Background technique [0002] With the increasing demand for electricity in modern society and the continuous development of new energy power generation, the capacity of the power grid is required to continue to increase. In order to improve the transmission capacity of the power grid, the utilization rate of new energy power generation and the strength of the power grid, the state proposes 1000kV UHV voltage Level, to interconnect the regional power grids. However, the interconnection of the power grid not only increases the voltage level of the power grid, but also increases the short-circuit current. However, the maximum breaking current of t...

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Problems solved by technology

[0005] However, in the stage of short-circuit current limiting, the iron core exits saturation, and since the DC winding is much larger than the number of turns of the AC winding, a large voltage will be induced in the DC winding, so the application voltage level is still limited

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