A power electronic type short-circuit fault current limiter

Abstract

The invention is a power-electronic short-circuit trouble current limiter, composed by using a variable impedance to replace bypass inductance and transformer in the existing short-circuit trouble current limiter. As compared with existing techniques, it not only omits the bypass inductance but also need not design according to working conditions of common transformer because the variable impedance transformer allows the magnetic circuit to enter saturation as short-circuiting, number of turns, iron core section area of the variable impedance transformer, etc, can largely be reduced, the weight, bulk and cost are remarkably reduced, and simultaneously because of the saturation of the transformer iron core and the increase of leakage impedance, the inductance quantity of current limiting impedance can be reduced, making the overcurrent level remarkably reduced. The invention can implement the industrialized wide application of the shor-circuit current limiter to single-phase and three-phase power systems.

Description

technical field [0001] The invention relates to a short-circuit fault current limiter for a power system. Background technique [0002] With the increasing grid-connected capacity of the power system, the requirements for the short-circuit capacity control of the line increase accordingly. Since the current mechanical switches are not capable of high-capacity, repetitive fast circuit breaking or current limiting, various short-circuit current limiters have been proposed. A large number of short-circuit current limiter circuits are still in the experimental and experimental stage. Due to factors such as performance and cost, no short-circuit current limiter has reached the stage of industrial application. [0003] Relatively speaking, in many short-circuit current limiter circuits, the solution using power electronic devices has the advantages of taking into account reliability, rapidity, and low cost. [0004] The disclosed single-phase short-circuit fault current limiter ...

AI Technical Summary

Problems solved by technology

Cost and device size are the main obstacles to its application, especially the limited space of existing substations in the power sector, and the huge short-circuit current limiter device will directly limit its application

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