A high-voltage short-circuit current limiting device and control method

Abstract

The invention discloses a high-voltage short-circuit current limiting device and a control method, comprising at least one fast switching module connected in parallel with at least one current limiting reactor, a fast switching branch current detection device, and a total current detection device. Each fast switch module includes 2 electromagnetic repulsion fast switches connected in series, 2 voltage equalizing capacitors, 1 energy storage and control unit and 1 isolated energy supply transformer. Each current-limiting reactor can be connected in parallel with all the series branches of the fast switching modules, or can be connected in parallel with one of the fast switching modules, or can be connected in parallel with one fast switch of electromagnetic repulsion. Through the above-mentioned device, the fast suppression of short-circuit current at high voltage levels can be realized, and the number and wiring mode of fast switching modules and current-limiting reactors can be flexibly adjusted according to actual applications. The current-limiting depth is flexible and controllable, and the structure is simple and easy. Realize the suppression of high-voltage short-circuit current.

Description

technical field [0001] The invention relates to the field of short-circuit fault current limiting in AC power systems, in particular to a high-voltage short-circuit current limiting device and a control method. Background technique [0002] Among all kinds of power system accidents, short circuit is one of the most common serious faults that endanger the safe and stable operation of the power system and cause large-scale power outages. The severity of the short-circuit fault damage to the power system mainly depends on the magnitude of the short-circuit current. In recent years, with the continuous development of my country's electric power construction, the continuous increase of power load, the application of low-impedance large-capacity transformers, the continuous increase in the capacity of power plants and generators, and the interconnection of power grids in various regions, the power system has The level of short-circuit current in many areas, especially in coastal e...

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Problems solved by technology

[0005] The advantage of the superconducting current limiter is the integration of detection, conversion, and current limiting, which can limit the current within milliseconds, but it is difficult to set the current in high-voltage applications; the solid-state current limiter has a fast response speed and can automatically exit after the fault is removed. However, relying on fault detection equipment, high overvoltage is generated when the fault is removed, and the series-parallel connection technology of power electronic switches is difficult and the reliability is not high; the structure of PTC thermistor is simple, no fault detection equipment is needed, and the response speed is fast, but the overvoltage is large and repetitive Poor usability, high voltage is difficult to apply; the arc current transfer topology is relatively simple, and the normal operation loss is small, but it is greatly affected by the arc voltage, so it is not suitable for high voltage occasions

[0006] The fault current limiting device using a mechanical switch shunt reactor has low loss, but because the opening time of the high-voltage mechanical switch is as long as tens of milliseconds, it cannot meet the needs of fast current limiting

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